P.B.B.Sc-F.Y-Biochemistry & Bio-Physics-SAURASHTRA UNIVERSITY-August 2018

SECTIONI (Biochemistry)

1 Long essays: (any 2) 2×10 = 20

💚 (1) Define Enzymes and explain factors affecting enzyme activities in detail.

❥Answer:-

Define Enzymes

An enzyme is a biological molecule, typically a protein, that acts as a catalyst in biochemical reactions. Enzymes accelerate the rate of chemical reactions by lowering the activation energy required for the reaction to occur, thereby facilitating the conversion of substrate molecules into products. Enzymes are highly specific in their action, typically catalyzing a specific chemical reaction or a group of closely related reactions. They play essential roles in metabolism, digestion, cellular signaling, and various other physiological processes in living organisms. Enzymes are characterized by their substrate specificity, catalytic efficiency, and regulation by factors such as pH, temperature, and cofactors.

An enzyme is a protein molecule that acts as a biological catalyst, speeding up chemical reactions within living organisms without being consumed or permanently altered in the process. Enzymes play critical roles in various biochemical processes, including metabolism, digestion, and cellular signaling.

Here’s a breakdown of the factors affecting enzyme activities:

1. Temperature: Enzyme activity is highly sensitive to temperature changes. As temperature increases, enzyme activity generally increases due to greater kinetic energy, which enhances molecular collisions and substrate binding. However, enzymes have optimal temperature ranges at which they function most effectively. Beyond this range, high temperatures can denature enzymes, causing them to lose their shape and function irreversibly.
2. pH: Enzyme activity is also influenced by pH, which affects the ionization state of amino acid residues in the enzyme’s active site. Each enzyme has an optimal pH at which it functions most efficiently. Deviations from this pH can disrupt the enzyme’s structure and alter its ability to bind to substrates. Extreme pH levels can denature enzymes, rendering them inactive.
3. Substrate Concentration: Enzyme activity is directly proportional to substrate concentration up to a certain point. At low substrate concentrations, enzyme activity increases as more substrate molecules are available to bind to enzyme active sites. However, once all active sites are saturated with substrate, further increases in substrate concentration will not increase enzyme activity as the enzymes are working at their maximum capacity (enzyme saturation).
4. Enzyme Concentration: Enzyme activity is directly proportional to enzyme concentration, assuming that substrate concentration is not a limiting factor. Increasing enzyme concentration increases the number of active sites available for substrate binding, leading to higher rates of reaction until all substrate molecules are utilized.
5. Presence of Inhibitors: Enzyme activity can be inhibited by various molecules known as inhibitors. Inhibitors can be classified as competitive or non-competitive based on their mode of action. Competitive inhibitors compete with substrates for binding to the active site, thereby reducing enzyme activity. Non-competitive inhibitors bind to allosteric sites on the enzyme, causing a conformational change that inhibits substrate binding or catalysis.
6. Cofactors and Coenzymes: Enzyme activity may require the presence of cofactors or coenzymes, which are non-protein molecules that assist in catalysis. Cofactors may be inorganic ions (e.g., magnesium, zinc) or organic molecules (e.g., vitamins). Coenzymes are organic molecules, often derived from vitamins, that participate in enzyme-catalyzed reactions by transferring chemical groups between substrates.
7. Enzyme Activation: Some enzymes require activation before they can catalyze reactions effectively. Activation may involve the removal of inhibitory molecules or the addition of specific cofactors or coenzymes. Enzyme activation mechanisms vary depending on the enzyme and the specific biochemical pathway involved.

Understanding these factors is crucial for optimizing enzyme activity in various biological processes and industrial applications. By manipulating these factors, researchers can modulate enzyme activity to achieve desired outcomes in fields such as medicine, biotechnology, and food processing.

💚 (2) What is normal blood glucose level? Explain regulation of blood glucose level.

❥Answer:-

The normal blood glucose level, measured in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L), varies depending on several factors such as age, fasting status, and individual health conditions. However, here are generally accepted ranges:

Fasting Blood Glucose (FBG): This refers to the blood glucose level measured after an overnight fast (usually 8-12 hours without eating). The normal range for fasting blood glucose is typically:

• Between 70 to 100 mg/dL (3.9 to 5.6 mmol/L) for adults without diabetes.
• Between 70 to 130 mg/dL (3.9 to 7.2 mmol/L) for adults with diabetes, according to the American Diabetes Association (ADA).

Postprandial Blood Glucose (PPBG): This refers to the blood glucose level measured after eating a meal. The normal range for postprandial blood glucose can vary, but it’s generally considered to be:

• Less than 180 mg/dL (10.0 mmol/L) two hours after eating, according to the ADA.

Random Blood Glucose: This refers to the blood glucose level measured at any time during the day, regardless of fasting status. For random blood glucose levels, the normal range is typically:

• Less than 200 mg/dL (11.1 mmol/L) in adults, according to the ADA.

The regulation of blood glucose level is a tightly controlled process that involves multiple organs, hormones, and biochemical pathways working together to maintain blood glucose within a narrow range. The primary hormones involved in blood glucose regulation are insulin and glucagon, which are produced by the pancreas.

Pancreatic Regulation:

• Insulin: When blood glucose levels rise after a meal, beta cells in the pancreas release insulin into the bloodstream. Insulin promotes the uptake of glucose by cells, where it can be used for energy production or stored as glycogen (a storage form of glucose) in the liver and muscles. Insulin also inhibits the breakdown of glycogen and promotes the synthesis of fatty acids and proteins.
• Glucagon: Conversely, when blood glucose levels drop, alpha cells in the pancreas secrete glucagon. Glucagon stimulates the breakdown of glycogen in the liver (glycogenolysis) and the synthesis of new glucose molecules from non-carbohydrate sources such as amino acids and glycerol (gluconeogenesis). This process increases blood glucose levels and provides a steady supply of glucose to tissues, especially during periods of fasting or prolonged exercise.

Liver Regulation:

• The liver plays a central role in blood glucose regulation by storing and releasing glucose as needed. After a meal, excess glucose is taken up by the liver and stored as glycogen through glycogenesis. Between meals or during fasting, the liver releases glucose into the bloodstream through glycogenolysis and gluconeogenesis to maintain blood glucose levels within the normal range.

Muscle and Adipose Tissue:

• Muscle tissue can also take up glucose from the bloodstream in response to insulin, where it is used for energy production during physical activity or stored as glycogen for later use.
• Adipose tissue can take up glucose and convert it into fatty acids for storage as triglycerides. Insulin promotes this process, particularly after a meal when blood glucose and insulin levels are elevated.

Other Hormones:

• Several other hormones also play roles in blood glucose regulation, including cortisol, epinephrine (adrenaline), and growth hormone. These hormones can counteract the effects of insulin and glucagon under certain conditions, such as stress or physical activity, to maintain blood glucose levels within the normal range.

Central Regulation:

• The hypothalamus and brainstem also contribute to blood glucose regulation by sensing changes in blood glucose levels and initiating appropriate physiological responses, such as hunger, satiety, and hormonal secretion, to maintain glucose homeostasis.

Overall, blood glucose regulation is a complex and dynamic process involving the coordinated actions of multiple organs, hormones, and signaling pathways to ensure that cells receive a constant supply of glucose for energy production and metabolic functions while preventing hyperglycemia (high blood glucose) or hypoglycemia (low blood glucose), both of which can have adverse health effects.

💚 (3) What is human cell? Describe structure and functions of cell membrane in detail.

❥Answer:-

A human cell is the basic structural and functional unit of the human body, as well as all living organisms. Each cell is a microscopic structure that performs specific functions necessary for the survival and proper functioning of the organism as a whole. Human cells contain various organelles, molecules, and structures that work together to carry out essential processes such as metabolism, growth, reproduction, and response to stimuli.

Here are some key features of human cells:

1. Cell Membrane: Also known as the plasma membrane, it surrounds the cell and serves as a barrier between the cell’s internal environment (cytoplasm) and the external environment. The cell membrane regulates the passage of substances into and out of the cell and plays a role in cell signaling and communication.
2. Cytoplasm: This is the gel-like substance that fills the interior of the cell, surrounding the organelles. It contains various molecules, ions, and structures necessary for cellular metabolism and function.
3. Nucleus: The nucleus is often referred to as the control center of the cell. It contains the cell’s genetic material in the form of DNA (deoxyribonucleic acid), organized into chromosomes. The nucleus regulates gene expression and directs cellular activities by controlling the synthesis of proteins and other molecules.
4. Organelles: These are specialized structures within the cell that perform specific functions. Examples of organelles include mitochondria (responsible for energy production), endoplasmic reticulum (involved in protein synthesis and lipid metabolism), Golgi apparatus (involved in protein modification and packaging), lysosomes (involved in intracellular digestion and waste removal), and ribosomes (responsible for protein synthesis).
5. Cytoskeleton: The cytoskeleton is a network of protein filaments that provides structural support to the cell and facilitates cell movement, shape maintenance, and intracellular transport of organelles and vesicles.
6. Mitochondria: These are often referred to as the “powerhouses” of the cell because they generate adenosine triphosphate (ATP), the primary energy currency of the cell, through cellular respiration.
7. Endoplasmic Reticulum (ER): This organelle is involved in protein synthesis, lipid metabolism, and calcium storage. It consists of two regions: rough endoplasmic reticulum (RER), which is studded with ribosomes and involved in protein synthesis, and smooth endoplasmic reticulum (SER), which lacks ribosomes and is involved in lipid metabolism and detoxification.

The cell membrane, also known as the plasma membrane,

Structure:

1. Phospholipid Bilayer: The primary structural component of the cell membrane is a phospholipid bilayer. Phospholipids are amphipathic molecules with a hydrophilic (water-attracting) head and two hydrophobic (water-repellent) tails. In the bilayer, phospholipids arrange themselves so that their hydrophilic heads face outward toward the aqueous environments (both inside and outside the cell), while their hydrophobic tails are oriented inward, away from water.
2. Proteins: The cell membrane contains various proteins embedded within or attached to the phospholipid bilayer. Integral proteins span the membrane from one side to the other, while peripheral proteins are attached to the membrane surface. These proteins serve diverse functions, including transport of molecules across the membrane, cell signaling, cell recognition, and structural support.
3. Cholesterol: Cholesterol molecules are interspersed within the phospholipid bilayer, contributing to the fluidity and stability of the membrane. Cholesterol helps regulate membrane fluidity by preventing phospholipid molecules from packing too closely together, especially at high temperatures.
4. Glycolipids and Glycoproteins: Some lipids and proteins on the outer surface of the cell membrane have attached carbohydrate chains, forming glycolipids and glycoproteins. These molecules are involved in cell-cell recognition, cell adhesion, and signaling processes.
5. Membrane Fluidity: The cell membrane exhibits dynamic properties and can change its fluidity in response to environmental conditions and cellular needs. Phospholipids and cholesterol molecules can move laterally within the membrane, allowing for flexibility and adaptability.

Functions:

1. Selective Permeability: One of the primary functions of the cell membrane is to regulate the movement of substances into and out of the cell. It selectively permits the passage of specific molecules while restricting the passage of others, based on factors such as size, charge, and solubility.
2. Transport: The cell membrane facilitates the transport of ions, nutrients, and other molecules across the membrane through various mechanisms, including passive diffusion, facilitated diffusion, active transport, and vesicular transport (endocytosis and exocytosis).
3. Cell Signaling: Proteins embedded in the cell membrane act as receptors for signaling molecules such as hormones, neurotransmitters, and growth factors. Binding of these molecules to their respective receptors triggers intracellular signaling cascades that regulate cellular responses such as gene expression, metabolism, and cell growth.
4. Cell Adhesion and Communication: The cell membrane plays a crucial role in cell adhesion, allowing cells to attach to neighboring cells and extracellular matrix components. It also facilitates cell-cell communication through direct physical contact and signaling interactions between membrane-bound proteins.
5. Protection and Defense: The cell membrane serves as a protective barrier, shielding the cell’s internal environment from harmful substances and pathogens. It also plays a role in immune responses by recognizing foreign invaders and initiating immune reactions.
6. Maintaining Cell Shape and Integrity: The cell membrane provides structural support and maintains the shape and integrity of the cell. It prevents the leakage of cellular contents and helps regulate cell volume by controlling the movement of water and solutes.

2 Write short notes: (any 3) 3×5 = 15

💚 (a) Importance of study of Biochemistry in nursing

❥Answer:-

Understanding the story of biochemistry is crucial for nurses for several reasons:

1. Foundation of Physiology: Biochemistry provides the foundational knowledge of how the human body functions at a cellular and molecular level. Nurses need to understand these basic processes to comprehend the mechanisms underlying diseases and treatments.
2. Medication Administration: Knowledge of biochemistry helps nurses understand how medications work within the body. This includes absorption, distribution, metabolism, and excretion (ADME) processes, as well as drug interactions and side effects.
3. Patient Assessment: Biochemical markers are often used in patient assessment and diagnosis. Understanding these markers allows nurses to interpret lab results accurately and identify abnormalities that may indicate disease or inform treatment decisions.
4. Nutrition and Diet: Biochemistry is fundamental to understanding the role of nutrients in the body and their impact on health. Nurses can provide valuable guidance to patients on nutrition and dietary choices based on biochemical principles.
5. Monitoring and Intervention: In critical care settings, nurses monitor biochemical parameters such as blood glucose levels, electrolyte balance, and acid-base status. This knowledge helps them recognize and respond to imbalances promptly, potentially preventing complications.
6. Patient Education: Nurses play a vital role in patient education. Knowledge of biochemistry enables them to explain complex medical concepts in a way that patients can understand, empowering patients to participate actively in their care and make informed decisions about their health.
7. Research and Evidence-Based Practice: Understanding biochemistry allows nurses to critically evaluate research findings and incorporate evidence-based practices into their patient care. It enables them to stay updated with advancements in medical science and apply them effectively in clinical settings.

💚 (b) pH and Buffers

❥Answer:-

👉let’s delve into pH and buffers in biochemistry.

pH in Biochemistry:

pH is a measure of the acidity or alkalinity of a solution and is defined as the negative logarithm of the hydrogen ion concentration ([H+]) in a solution. The pH scale ranges from 0 to 14, where:

• pH < 7 indicates an acidic solution.
• pH = 7 indicates a neutral solution (pure water).
• pH > 7 indicates an alkaline or basic solution.

In biological systems, maintaining the pH is crucial for the proper functioning of enzymes, proteins, and other biomolecules. Most biological processes occur optimally at a pH close to 7.4, which is slightly alkaline, similar to the pH of blood.

Buffers in Biochemistry:

Buffers are solutions that resist changes in pH when small amounts of acid or base are added. They consist of a weak acid and its conjugate base or a weak base and its conjugate acid.

Buffering capacity is essential in biological systems to maintain the stability of pH, which is vital for cellular processes. For example, the blood contains buffers like bicarbonate (HCO3-) and carbonic acid (H2CO3) to maintain its pH around 7.4.

Key Points :

1. pH Definition: pH measures the acidity or alkalinity of a solution.
2. pH Scale: Ranges from 0 to 14; pH < 7 is acidic, pH = 7 is neutral, and pH > 7 is alkaline.
3. Importance of pH in Biology: Optimal pH is crucial for enzyme and protein function; most biological processes occur around pH 7.4.
4. Buffer Definition: Solutions that resist changes in pH by neutralizing added acids or bases.
5. Role of Buffers in Biological Systems: Buffers maintain pH stability, essential for cellular function; examples include bicarbonate and carbonic acid in blood.

💚 (C) Urea cycle

❥Answer:-

👉The urea cycle, also known as the ornithine cycle, is a series of biochemical reactions that occur in the liver. Its primary function is to remove toxic ammonia from the bloodstream by converting it into urea, which is then excreted in urine.

Here’s a detailed breakdown of the urea cycle:

1. Ammonia Detoxification:
   The urea cycle starts with the conversion of ammonia (NH3) into carbamoyl phosphate in the mitochondria of liver cells. This reaction requires the enzyme carbamoyl phosphate synthetase I (CPS I) and uses one molecule of ATP.
2. Formation of Citrulline:
   Carbamoyl phosphate combines with ornithine to form citrulline. This reaction is catalyzed by the enzyme ornithine transcarbamylase (OTC). Citrulline is transported out of the mitochondria into the cytosol.
3. Formation of Argininosuccinate:
   In the cytosol, citrulline reacts with aspartate to form argininosuccinate. This reaction is catalyzed by the enzyme argininosuccinate synthetase and requires ATP.
4. Formation of Arginine and Fumarate:
   Argininosuccinate is then cleaved into arginine and fumarate by the enzyme argininosuccinate lyase.
5. Formation of Urea and Regeneration of Ornithine:
   Arginine is hydrolyzed by the enzyme arginase to produce urea and regenerate ornithine. Ornithine can then re-enter the cycle to combine with another molecule of carbamoyl phosphate, restarting the cycle.

The urea produced in the liver is then transported to the kidneys, filtered out of the blood, and excreted in the urine.

Any disruption in the urea cycle can lead to the accumulation of ammonia in the blood, causing hyperammonemia, which is toxic to the brain and other tissues. This condition requires immediate medical attention and treatment.

💚 (d) Anabolism and Cataholism of Fat.

❥Answer:-

👉here’s a detailed explanation of anabolism and catabolism of fat:

Anabolism of Fat:

Anabolism refers to the metabolic processes that build larger molecules from smaller ones.

In the context of fat metabolism, anabolism involves the synthesis of fat molecules from smaller precursors.

Lipogenesis: This is the primary anabolic pathway for fat synthesis. It occurs mainly in the liver and adipose tissue.

Acetyl-CoA, derived from the metabolism of carbohydrates, proteins, or fatty acids, serves as the building block for fatty acid synthesis. Through a series of enzymatic reactions, acetyl-CoA is converted into fatty acids, which are then combined with glycerol to form triglycerides.

These triglycerides are stored in adipose tissue for future energy use.

Catabolism of Fat:

Catabolism involves the breakdown of larger molecules into smaller ones to release energy.

In the context of fat metabolism, catabolism refers to the breakdown of triglycerides into fatty acids and glycerol to produce energy.

1. Lipolysis: This is the primary catabolic pathway for fat breakdown. It occurs mainly in adipose tissue and is stimulated by hormones like epinephrine and glucagon.

In lipolysis, triglycerides stored in adipose tissue are hydrolyzed by lipase enzymes into fatty acids and glycerol. These fatty acids are released into the bloodstream and transported to various tissues where they can be oxidized to produce energy.

In summary, anabolism involves the synthesis of fat molecules from smaller precursors through lipogenesis, while catabolism involves the breakdown of fat molecules into smaller components through lipolysis to release energy.

These processes play crucial roles in energy balance and metabolism in the body.

3 Write answers following in brief: (any 3) 1×3 = 3

💚 (a) Enlist different tests for Renal functions.

❥Answer:-

Several tests are used to assess renal function, which involves evaluating the kidneys’ ability to filter waste products from the blood, regulate fluid and electrolyte balance, and produce urine. Here are some commonly used tests for renal function:

1. Serum Creatinine: Serum creatinine is a waste product generated by muscle metabolism that is filtered by the kidneys. Elevated levels of serum creatinine indicate impaired kidney function, as the kidneys are less able to clear creatinine from the blood. Serum creatinine levels are used to estimate the glomerular filtration rate (GFR), a measure of kidney function.
2. Blood Urea Nitrogen (BUN): Blood urea nitrogen is a waste product derived from the breakdown of protein in the liver. Elevated BUN levels can indicate impaired kidney function, as the kidneys are responsible for excreting urea from the body. BUN levels can be affected by factors such as diet, hydration status, and liver function.
3. Glomerular Filtration Rate (GFR): GFR is a measure of the kidneys’ ability to filter waste products from the blood. It is considered the best indicator of overall kidney function. GFR can be estimated using equations based on serum creatinine levels, age, gender, and other factors. A decrease in GFR indicates impaired kidney function.
4. Urinalysis: Urinalysis involves testing a urine sample for various parameters, including pH, specific gravity, protein, glucose, ketones, blood cells, and bacteria. Abnormalities in urine composition can indicate kidney dysfunction, urinary tract infections, or other urinary tract disorders.
5. Creatinine Clearance: Creatinine clearance is a measure of the kidneys’ ability to filter creatinine from the blood into the urine over a specified period. It is calculated using a 24-hour urine collection and a simultaneous measurement of serum creatinine. Creatinine clearance provides an estimate of GFR and is used to assess kidney function more accurately than serum creatinine alone.
6. Urea Clearance: Urea clearance is a measure of the kidneys’ ability to remove urea from the blood into the urine. It is calculated using a 24-hour urine collection and a simultaneous measurement of serum urea nitrogen. Urea clearance can provide additional information about kidney function, particularly in patients with liver disease or altered protein intake.
7. Fractional Excretion of Sodium (FENa): FENa is a measure of the percentage of filtered sodium that is excreted in the urine compared to the amount filtered by the kidneys. It is used to differentiate between prerenal (dehydration, hypovolemia) and intrinsic renal (acute tubular necrosis, glomerulonephritis) causes of acute kidney injury.
8. Renal Ultrasonography: Renal ultrasonography uses sound waves to create images of the kidneys and urinary tract. It can identify structural abnormalities such as kidney stones, cysts, tumors, or obstruction that may affect kidney function.
9. Renal Biopsy: Renal biopsy involves obtaining a small sample of kidney tissue for microscopic examination. It is performed to diagnose and evaluate the severity of kidney diseases such as glomerulonephritis, nephrotic syndrome, and renal amyloidosis.

These tests, along with clinical assessment and medical history, help healthcare providers evaluate renal function, diagnose kidney disorders, and monitor the progression of kidney disease. Depending on the specific clinical situation, additional tests such as imaging studies (CT scan, MRI) or specialized urine tests (proteinuria, albuminuria) may also be performed.

💚 (b) Write full form of “TCA” cycle and site of its occurrence.

❥Answer:-

The Tricarboxylic Acid (TCA) cycle, also known as the Citric Acid cycle or Krebs cycle, is a series of biochemical reactions that occur in the mitochondria of eukaryotic cells and in the cytoplasm of prokaryotic cells. It is a central pathway of cellular respiration, which is the process by which cells generate energy (in the form of adenosine triphosphate or ATP) from the breakdown of nutrients, particularly carbohydrates, fats, and proteins.

The Tricarboxylic Acid (TCA) cycle, also known as the Krebs cycle or the Citric Acid cycle, occurs in the mitochondrial matrix of eukaryotic cells. The mitochondrial matrix is the innermost compartment of the mitochondria, which are often referred to as the “powerhouses” of the cell due to their role in energy production.

💚 (C) Structure of Amino acids.

❥Answer:-

Amino acids are organic compounds that serve as the building blocks of proteins. They contain an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a side chain (also known as R group) attached to a central carbon atom (the alpha carbon). The structure of amino acids can vary based on the specific side chain, which gives each amino acid its unique properties.

Here’s a breakdown of the general structure of amino acids:

1. Amino Group (-NH2): This group consists of a nitrogen atom bonded to two hydrogen atoms. It acts as a base and can accept a proton (H+) to become positively charged (+NH3+) under acidic conditions.
2. Carboxyl Group (-COOH): This group consists of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (-OH). It acts as an acid and can donate a proton (H+) to become negatively charged (-COO-) under basic conditions.
3. Alpha Carbon (α-C): The alpha carbon is the central carbon atom to which the amino group, carboxyl group, hydrogen atom, and side chain are attached.
4. Side Chain (R Group): The side chain varies among different amino acids and determines their chemical properties, such as polarity, charge, size, and reactivity. There are 20 standard amino acids found in proteins, each with a unique side chain. The side chain can be nonpolar (hydrophobic), polar (hydrophilic), acidic (negatively charged), or basic (positively charged), depending on its chemical composition.

💚 (d) What are Free Radicals?

❥Answer:-

Free radicals are highly reactive molecules or atoms that contain one or more unpaired electrons in their outer shell. Because of this unpaired electron, free radicals are unstable and highly reactive, seeking to gain or lose electrons through chemical reactions in order to achieve stability. Free radicals can be formed through various physiological and environmental processes, including metabolism, exposure to ultraviolet (UV) radiation, pollution, smoking, and certain chemicals.

1. Formation: Free radicals are formed during normal metabolic processes in the body, such as cellular respiration and immune responses, where oxygen is utilized. They can also be generated by external sources such as UV radiation from the sun, air pollution, cigarette smoke, and certain chemicals.
2. Reactivity: Because free radicals contain unpaired electrons, they are highly reactive and can readily interact with other molecules, including lipids, proteins, and DNA, by donating or accepting electrons. These interactions can lead to the oxidation of biomolecules and the generation of more free radicals in a chain reaction known as oxidative stress.
3. Types: Common types of free radicals include superoxide anion (O2•−), hydroxyl radical (•OH), and nitric oxide (•NO). Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are broader categories that encompass various free radicals and non-radical molecules with reactive properties.
4. Role in Health and Disease: In small amounts, free radicals play important roles in physiological processes such as cell signaling, immune defense, and apoptosis (programmed cell death). However, excessive or uncontrolled production of free radicals can lead to oxidative damage to biomolecules, contributing to the development of various diseases, including cancer, cardiovascular disease, neurodegenerative disorders, and aging.
5. Antioxidants: Antioxidants are molecules that neutralize free radicals by donating electrons without becoming reactive themselves. Antioxidants can be enzymatic (e.g., superoxide dismutase, catalase) or non-enzymatic (e.g., vitamins C and E, glutathione), and they play a crucial role in maintaining cellular redox balance and protecting cells from oxidative damage.
6. Sources of Antioxidants: Antioxidants are found in a variety of foods, particularly fruits, vegetables, nuts, seeds, and whole grains. Consuming a diet rich in antioxidants can help counteract the effects of oxidative stress and reduce the risk of chronic diseases associated with free radical damage.

SECTION II (Bio-Physics)

Long essay questions: (any 1) 2+8-10

💚 (A)Define the gravitational force.

❥Answer:-

In biophysics, gravitational force refers to the attraction between two objects with mass due to gravity. In biological systems, gravity plays a crucial role in various processes, including the orientation of cells and organisms, the regulation of cell growth and differentiation, and the function of specialized structures such as the inner ear’s otolith organs, which help in balance and spatial orientation. Understanding gravitational forces in biophysics involves studying how living organisms sense, respond to, and adapt to gravitational cues, both on Earth and in other environments such as space. This field encompasses research on topics such as gravitational biology, space physiology, and biomechanics.

💚 (B) Explain effects of gravitational force on human body and its application in nursing.

❥Answer:-

👉Effects of Gravitational Force on the Human Body:

1. Bone Density: Gravity constantly exerts force on our bones, stimulating bone growth and density. However, in conditions of prolonged weightlessness, such as space travel, bone density can decrease due to lack of gravitational loading.
2. Muscle Strength: Gravity provides resistance against which muscles must work, contributing to muscle strength and tone. Lack of gravitational force, as experienced in microgravity environments, can lead to muscle atrophy and weakness.
3. Circulation: Gravity influences blood circulation by aiding venous return from the lower extremities to the heart. In upright positions, gravity assists in maintaining blood pressure and preventing pooling of blood in the lower limbs.
4. Fluid Distribution: Gravity affects the distribution of bodily fluids, causing them to accumulate in the lower body when standing or sitting upright. This can lead to conditions such as edema, especially in individuals with compromised circulation.
5. Posture and Alignment: The gravitational force influences posture and spinal alignment, as the body works to maintain balance against gravitational pull. Prolonged poor posture can lead to musculoskeletal issues such as back pain.

👉Applications in Nursing:

1. Mobility Assistance: Nurses utilize knowledge of gravitational effects to assist patients in maintaining mobility and preventing muscle atrophy. Rehabilitation programs often incorporate exercises to counteract the negative effects of reduced gravitational loading during periods of immobility.
2. Positioning Techniques: Nurses employ specific positioning techniques to optimize patient comfort and prevent complications such as pressure ulcers. Understanding how gravity affects pressure points helps nurses distribute pressure evenly and relieve areas of high pressure.
3. Falls Prevention: Nurses assess patients’ risk of falls, considering factors such as muscle weakness and postural instability exacerbated by gravitational effects. Fall prevention strategies may include environmental modifications and mobility aids to enhance patient safety.
4. Fluid Management: Nurses monitor patients for signs of fluid imbalance, recognizing the influence of gravity on fluid distribution within the body. Interventions such as elevation of the lower extremities or compression stockings may be used to mitigate edema and promote venous return.
5. Patient Education: Nurses educate patients about the importance of posture and mobility in maintaining overall health. They may provide guidance on ergonomic principles and exercises to improve posture and minimize the negative effects of gravitational force on musculoskeletal health.

OR

💚 (A) Define pressure.

❥Answer:-

n biophysics, pressure refers to the force exerted per unit area on a surface by a fluid or gas.

It is typically measured in pascals (Pa) or millimeters of mercury (mmHg). In biological systems, pressure plays a critical role in various physiological processes, such as blood circulation, respiration, and cellular functions.

Understanding pressure gradients and changes within the body is essential for studying these processes and their impact on overall health and function.

💚 (B) Explain application of various pressure in human body and nursing.

❥Answer:-

The application of various pressures in the human body plays a significant role in both healthcare and nursing practice. These pressures can be therapeutic, diagnostic, or preventive in nature, and they are applied in different ways to promote health, assess conditions, and manage illnesses. Here are some key applications of various pressures in the human body and nursing:

Compression Therapy:

• Compression therapy involves applying pressure to specific areas of the body to improve circulation, reduce swelling, and prevent blood clots. It is commonly used in the management of conditions such as venous insufficiency, lymphedema, and deep vein thrombosis.
• In nursing, compression stockings or bandages may be applied to the lower extremities to enhance venous return and prevent complications such as venous ulcers and edema.

Positive Airway Pressure (PAP) Therapy:

• Positive airway pressure therapy is used to treat sleep-related breathing disorders such as obstructive sleep apnea (OSA). It involves delivering pressurized air through a mask worn over the nose or face during sleep to keep the airway open and prevent breathing pauses.
• Nurses may educate patients on the use of PAP therapy, monitor treatment adherence and effectiveness, and provide support to patients experiencing challenges with mask fit or comfort.

Intermittent Pneumatic Compression (IPC):

• IPC devices apply intermittent pressure to the limbs through inflatable sleeves or cuffs, promoting venous return and preventing deep vein thrombosis (DVT) in patients at risk, such as those undergoing surgery or immobilized due to illness.
• Nurses may assess patients for DVT risk factors, apply IPC devices, monitor patient response, and educate patients on preventive measures and device use.

Negative Pressure Wound Therapy (NPWT):

• NPWT, also known as vacuum-assisted closure (VAC) therapy, involves applying negative pressure to a wound through a sealed dressing system. This promotes wound healing by reducing edema, removing excess fluid and debris, and stimulating tissue granulation and perfusion.
• Nurses may assess wounds, apply NPWT dressings, monitor wound progress, and provide patient education on wound care techniques and device management.

Intracranial Pressure (ICP) Monitoring:

• ICP monitoring involves measuring the pressure inside the skull to assess brain function and detect abnormalities such as increased intracranial pressure (ICP) due to head trauma, stroke, or intracranial hemorrhage.
• Nurses may assist with the placement of ICP monitoring devices, monitor ICP readings, and implement interventions to reduce ICP, such as elevating the head of the bed, administering medications, and optimizing cerebral perfusion.

Blood Pressure Monitoring:

• Blood pressure monitoring involves measuring the pressure exerted by circulating blood against the walls of blood vessels. It is essential for assessing cardiovascular health, diagnosing hypertension, and monitoring response to treatment.
• Nurses routinely measure blood pressure using sphygmomanometers, assess blood pressure trends, educate patients on lifestyle modifications and medication adherence, and collaborate with healthcare providers to manage hypertension effectively.

Overall, the application of various pressures in the human body is integral to nursing practice and patient care across a wide range of clinical settings. Nurses play a vital role in assessing, implementing, and monitoring pressure-related interventions to promote optimal health outcomes and enhance patient well-being.

2 Short essays: (any 3) 3+5 = 15

💚 (a) Regulation of body temperature

❥Answer:-

The regulation of body temperature, also known as thermoregulation, is a complex physiological process crucial for maintaining the body’s internal environment within a narrow temperature range conducive to optimal cellular function.

Here’s a detailed explanation of how the body regulates its temperature:

1. Thermoreceptors: Specialized nerve cells called thermoreceptors are distributed throughout the body, primarily in the skin, hypothalamus, and internal organs. These receptors continuously monitor the temperature of the surrounding environment and the body’s internal temperature.
2. Hypothalamus: The hypothalamus, located in the brain, serves as the body’s thermostat, receiving signals from thermoreceptors and coordinating the thermoregulatory responses. It contains specialized regions that control both heat conservation and heat loss mechanisms.Heat Production (Thermogenesis):

• Metabolism: The body generates heat as a byproduct of metabolic processes, particularly through the breakdown of nutrients such as carbohydrates, fats, and proteins.
• Muscle Activity: Physical activity, including muscle contractions, generates heat. Shivering, a rapid contraction and relaxation of muscles, is a mechanism to increase heat production when the body is cold.

Heat Loss (Thermal Dissipation):

• Radiation: The transfer of heat energy from the body’s surface to cooler surroundings through electromagnetic waves. This is the primary mode of heat loss at rest.
• Conduction: The transfer of heat between objects in direct contact. For example, sitting on a cold surface can result in heat loss through conduction.
• Convection: The transfer of heat through the movement of air or water molecules across the body’s surface. Wind and water currents can enhance heat loss through convection.
• Evaporation: The conversion of liquid water on the skin’s surface into vapor, which absorbs heat from the body. Sweating is the primary mechanism of evaporative heat loss and is controlled by the hypothalamus.

1. Vasomotor Responses: Blood vessels play a crucial role in thermoregulation by regulating blood flow to the skin. When the body needs to lose heat, such as in hot conditions, blood vessels dilate (vasodilation), allowing more blood to flow near the skin’s surface, facilitating heat loss through radiation and convection. Conversely, in cold conditions, blood vessels constrict (vasoconstriction), reducing blood flow to the skin to conserve heat.
2. Behavioral Responses: Humans can consciously adjust their behavior to regulate body temperature. Examples include seeking shade or shelter in hot conditions, wearing appropriate clothing, and engaging in physical activities to generate heat.
3. Hormonal Regulation: Hormones, such as thyroid hormone and adrenaline, can influence metabolic rate and heat production. Additionally, hormones like antidiuretic hormone (ADH) and aldosterone regulate fluid balance, which indirectly affects thermoregulation by influencing sweat production and water loss.
4. Fever Response: During infection or illness, the body may elevate its temperature as a defense mechanism to inhibit the growth of pathogens. The hypothalamus raises the body’s set point, leading to increased heat production and decreased heat loss until the infection is resolved.

💚 (B) Biological effects of light

❥Answer:-

Sure, here’s an overview of the biological effects of light ..

1. Circadian Rhythm Regulation: Light exposure, particularly blue light, plays a crucial role in regulating the body’s circadian rhythm, the internal clock that governs the sleep-wake cycle. Light exposure in the morning helps to wake us up and maintain alertness during the day, while exposure to dim or no light at night signals the body to prepare for sleep.
2. Melatonin Production: Light exposure influences the production of melatonin, a hormone that regulates sleep-wake cycles. Exposure to light, especially blue light from electronic devices, can suppress melatonin production, making it more difficult to fall asleep.
3. Vitamin D Synthesis: Sunlight is essential for the synthesis of vitamin D in the skin. When the skin is exposed to UVB radiation in sunlight, it converts a precursor molecule into vitamin D, which is crucial for bone health, immune function, and other physiological processes.
4. Mood Regulation: Light exposure, particularly natural sunlight, can affect mood and emotional well-being. Lack of sunlight, such as during the winter months in regions with shorter daylight hours, can lead to seasonal affective disorder (SAD), characterized by symptoms of depression.
5. Eye Health: Prolonged exposure to certain wavelengths of light, particularly blue light from screens, can contribute to digital eye strain and may increase the risk of age-related macular degeneration (AMD) over time. Protective measures such as blue light filters or reducing screen time before bedtime can help mitigate these effects.
6. Regulation of Hormones: Light exposure influences the secretion of various hormones beyond just melatonin, including cortisol (the stress hormone), serotonin (the mood-regulating neurotransmitter), and others. These hormones play essential roles in regulating mood, energy levels, and overall physiological function.
7. Photosynthesis in Plants: Light is essential for photosynthesis in plants, the process by which they convert light energy into chemical energy to fuel growth and development. Different wavelengths of light can have varying effects on plant growth and flowering patterns.
8. Skin Health: While moderate sun exposure is necessary for vitamin D synthesis, excessive exposure to UV radiation can damage the skin, leading to sunburn, premature aging, and an increased risk of skin cancer. It’s essential to strike a balance between adequate sun exposure for vitamin D production and protecting the skin from harmful UV rays.

💚 (C) Russel traction with diagram

❥Answer:-

Russell traction is a type of orthopedic traction commonly used to manage fractures of the femur. Here’s a detailed explanation with a diagram:

1. Purpose: Russell traction aims to stabilize and align the fractured bone, reducing pain and preventing further damage.
2. Components:

• Skin Traction: In Russell traction, adhesive strips or a boot is applied to the skin of the leg. These strips are connected to a traction apparatus, usually ropes or cords, which are attached to weights.
• Countertraction: To provide stability and prevent the patient from sliding down the bed, a countertraction force is applied. This is usually achieved by elevating the foot of the bed or by using a splint under the unaffected leg.

Application:

• The adhesive strips or boot are applied to the skin of the patient’s leg, just below the knee.
• The traction apparatus is then connected to these strips or the boot.
• Weights are attached to the traction apparatus. The amount of weight used depends on the patient’s age, weight, and the severity of the fracture.

Mechanism:

• The weights exert a continuous pulling force on the fractured bone, helping to align it properly.
• This pulling force also helps to relieve pressure on the surrounding muscles and tissues, reducing pain and promoting healing.

Monitoring:

• Russell traction requires regular monitoring to ensure that the traction is maintained and that the skin underneath the adhesive strips or boot is not being damaged.
• Nurses or healthcare providers should check the patient’s circulation, sensation, and movement regularly to detect any complications.

Precautions:

• Care must be taken to avoid pressure points and skin breakdown under the adhesive strips or boot.
• Patients should be educated about the signs of complications, such as numbness, tingling, or skin discoloration, and instructed to report them immediately.

Duration:

• Russell traction is typically used until the fracture is stable enough for other forms of treatment, such as surgery or casting.

Here’s a simple diagram to illustrate Russell traction:

      ___________________________
     |                           |
     |          Weights          |
     |___________________________|
                |
                |
     ___________V___________
    |                       |
    |  Traction Apparatus  |
    |_______________________|
                |
                |
     ___________V___________
    |                       |
    |    Adhesive Strips    |
    |_______________________|
                |
                |
     ___________V___________
    |                       |
    |       Patient's Leg    |
    |_______________________|

This diagram illustrates the basic setup of Russell traction, with weights attached to a traction apparatus, which is connected to adhesive strips applied to the patient’s leg.

💚 (D) Concept of unit and measurement

❥Answer:-

👉In biophysics, the concepts of units and measurements are essential for understanding and quantifying biological processes at various levels, from molecular to organismal scales. Here’s a detailed overview:

Units in Biophysics:

1. Base Units: Biophysics, like other scientific disciplines, uses the International System of Units (SI) for measurements. The base units commonly used in biophysics include:

• Length: Meter (m)
• Mass: Kilogram (kg)
• Time: Second (s)
• Temperature: Kelvin (K)

Derived Units: These are combinations of base units that represent specific quantities. Examples in biophysics include:

• Force: Newton (N) – kg·m/s^2
• Pressure: Pascal (Pa) – N/m^2
• Energy: Joule (J) – N·m or kg·m^2/s^2

Measurements in Biophysics:

1. Length and Size: Measurements of biological structures range from nanometers (nm) for molecules to meters (m) for organisms.
2. Mass: Mass measurements are used to quantify the amount of biological substances, from picograms (pg) for small molecules to kilograms (kg) for organisms.
3. Time: Time measurements are crucial for studying dynamic biological processes. Techniques like fluorescence microscopy or electrophysiology often require precise timing.
4. Concentration: Concentration measurements quantify the amount of a substance in a given volume. Common units include moles per liter (mol/L) or milligrams per milliliter (mg/mL).
5. Electricity and Magnetism: Biophysical techniques like electrophysiology involve measurements of electrical currents, which are quantified in amperes (A) or milliamperes (mA).
6. Optical Properties: Light absorption, emission, and scattering properties are measured in units like absorbance (AU), lumens (lm), or lux (lx).

💚 (E) ECG.

❥Answer:-

Definition: ECG is a test that records the electrical activity of the heart over a period of time.

Purpose:

• To detect and diagnose heart conditions
• Assess the heart’s rhythm and rate
• Identify damage to the heart muscle

Components:

• P wave: Represents atrial depolarization (contraction).
• QRS complex: Represents ventricular depolarization (contraction).
• T wave: Represents ventricular repolarization (relaxation).

Lead Placement:

• Standard 12-lead ECG: 10 electrodes placed on the chest and limbs.
• Each lead provides a different view of the heart’s electrical activity.

Normal ECG:

• Regular rhythm (60-100 beats per minute)
• Well-defined P waves, QRS complexes, and T waves
• No signs of ischemia, injury, or infarction

Abnormal Findings:

• Arrhythmias: Irregular heart rhythms
• Ischemia: Reduced blood flow to the heart
• Injury: Damage to the heart muscle
• Infarction: Heart attack

Clinical Applications:

• Chest pain evaluation
• Pre-surgical assessment
• Monitoring response to treatment

Limitations:

• Does not provide anatomical information
• May not detect all types of heart conditions
• Interpretation requires expertise

3 Write very short essays: (all compulsory)6X2 = 12

💚 (A)Four common electronic equipments used in patients care

❥Answer:-

1. Electrocardiogram (ECG or EKG) machine: Used to monitor and record the electrical activity of the heart.
2. Pulse oximeter: Measures the oxygen saturation level in the blood and heart rate.
3. Ventilator: Assists patients with breathing by delivering oxygen to the lungs and removing carbon dioxide.
4. Infusion pump: Administers fluids, medications, or nutrients to patients in a controlled manner through an IV.

💚 (b) Newton’s law of motion

❥Answer:-

👉Newton’s Law of Motion applies to biophysics as it governs the movement of biological systems. The three laws are:

1. First Law (Law of Inertia): An object remains at rest or in uniform motion unless acted upon by an external force.
2. Second Law (F = ma): The force acting on an object is equal to the mass of the object multiplied by its acceleration.
3. Third Law (Action and Reaction): For every action, there is an equal and opposite reaction.

💚 (C)Methods of reducing friction

❥Answer:-

👉Reducing friction in biophysics can be achieved through several methods:

1. Lubrication: Introducing lubricants between surfaces to reduce direct contact and friction.
2. Surface Modification: Altering surface properties to reduce friction, such as coating with polymers or changing surface roughness.
3. Design Optimization: Modifying the design of interacting components to minimize contact and frictional forces.
4. Temperature Control: Adjusting the temperature to reduce friction by altering the viscosity of lubricants or changing material properties.

💚 (D)Application of measurement in nursing

❥Answer:-

👉Measurement plays a crucial role in nursing and biophysics by providing quantitative data for diagnosis, treatment, and monitoring of patients.

In nursing, measurements such as blood pressure, temperature, and heart rate help in assessing a patient’s health status and response to treatment.

In biophysics, measurements are used to study biological systems at the molecular and cellular levels, providing insights into their structure and function. These measurements contribute to advancements in medical research, drug development, and personalized medicine.

💚 (E) Use of ultrasound

❥Answer:-

👉Some key uses include:

1. Medical Imaging: Ultrasound imaging, also known as sonography, is widely used for diagnostic purposes to visualize internal organs, tissues, and blood flow.
2. Therapeutic Ultrasound: High-intensity focused ultrasound (HIFU) can be used for targeted tissue ablation, treating tumors, and relieving pain.
3. Drug Delivery: Ultrasound can enhance the delivery of therapeutic agents by increasing permeability of cell membranes or aiding in the release of encapsulated drugs.
4. Tissue Characterization: Ultrasound elastography measures tissue stiffness, providing valuable information for diagnosing diseases like liver fibrosis or breast cancer.
5. Blood Flow Measurement: Doppler ultrasound allows for the assessment of blood flow velocity and direction, aiding in the diagnosis of cardiovascular diseases.

💚 (F) Radioactive isotopes.

❥Answer:-

Radioactive isotopes are used as tracers to study biological processes, diagnose diseases, and treat various medical conditions.

◾For example:

1. Tracers in Research: Radioactive isotopes can be incorporated into molecules like DNA, RNA, or proteins to trace their movement and interactions within biological systems.
2. Medical Imaging: Isotopes emitting gamma radiation, such as technetium-99m, are commonly used in medical imaging techniques like Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET).
3. Cancer Treatment: Radioactive isotopes can be used in targeted radiation therapy to treat cancer by destroying cancer cells or inhibiting their growth.
4. Radioimmunoassays: This technique uses radioactive isotopes to measure concentrations of specific molecules, like hormones or drugs, in biological samples.