Question 1

Chitin is A ...?

Accepted Answer

Answer reason: Chitin is a structural carbohydrate composed of long chains of N-acetylglucosamine units linked by β(1→4) bonds, making it a polysaccharide. It is a major component of arthropod exoskeletons and fungal cell walls. Because it is a polymer of many monosaccharide units, it cannot be classified as a disaccharide. It is also not a lipid (phospholipid) or a protein-carbohydrate conjugate (glycoprotein).

Question 2

Which of the following is not an activated carrier?

Accepted Answer

Answer reason: Activated carriers are energy-rich molecules that transfer specific chemical groups or electrons in metabolic reactions. ATP transfers phosphoryl groups and energy, SAM transfers methyl groups, and TPP (thiamine pyrophosphate) carries activated aldehyde units in decarboxylation/transketolase reactions. GMP is primarily a nucleotide monophosphate used in nucleic acid metabolism and signaling (as a precursor to cGMP), but it is not classically categorized as an activated carrier in intermediary metabolism.

Question 3

Fat is stored in the body in the form of?

Accepted Answer

Answer reason: In humans, most fat is stored in adipose tissue primarily as triglycerides (triacylglycerols), which are the main long-term energy storage molecules. Proteins are mainly structural/functional molecules and are not the body’s primary storage form for fat energy. Glycogen is the storage form of glucose (carbohydrate) in liver and muscle, and water is not an energy storage molecule.

Question 4

An Example Of Polar amino acid is?

Accepted Answer

Answer reason: Arginine has a basic, positively charged guanidinium side chain at physiologic pH, making it a polar (hydrophilic) amino acid. In contrast, leucine, alanine, and valine have nonpolar aliphatic side chains and are classified as hydrophobic amino acids. Therefore, among the options listed, arginine is the best example of a polar amino acid.

Question 5

Enzyme are polymer of?

Accepted Answer

Answer reason: Most enzymes are proteins, and proteins are polymers (polypeptides) made from amino acid monomers linked by peptide bonds. The sequence and folding of these amino acids create the enzyme’s active site and determine its catalytic function. While some enzymes are RNA (ribozymes), among the given options the correct polymer building block for enzymes is amino acids.

Question 6

Fats are also called?

Accepted Answer

Answer reason: Fats are a major class of biomolecules collectively referred to as lipids, which includes triglycerides, phospholipids, and sterols. Proteins and sugars are different macronutrient classes (amino acid polymers and carbohydrates, respectively). Vitamins are micronutrients and are not synonymous with fats, although some vitamins are fat-soluble.

Question 7

Glucose is also commonly known as?

Accepted Answer

Answer reason: Glucose is the primary monosaccharide circulating in the bloodstream and is routinely measured as “blood glucose,” so it is commonly called blood sugar. “Fruit sugar” typically refers to fructose, “milk sugar” to lactose, and “table sugar” to sucrose. Therefore, blood sugar is the best match for glucose in common usage and clinical context.

Question 8

Amino Acid mainly differ from each other BY?

Accepted Answer

Answer reason: All amino acids share the same core structure: an alpha carbon bonded to an amino group and a carboxyl group (and a hydrogen). The component that varies among different amino acids is the side chain, called the R group. Differences in the R group determine an amino acid’s size, charge, polarity, and overall chemical behavior in proteins.

Question 9

Enzyme Peptidases belong to the ______ Categories of Enzymes?

Accepted Answer

Answer reason: Peptidases (proteases) catalyze hydrolysis of peptide bonds in proteins, using water to cleave the bond. Enzymes that break chemical bonds by adding water are classified as hydrolases (EC class 3). Lyases typically add/remove groups to form double bonds without hydrolysis, transferases transfer functional groups, and reductases catalyze redox reactions. Therefore, peptidases are hydrolases.

Question 10

Which vitamin is essential for collagen formation?

Accepted Answer

Answer reason: Vitamin C (ascorbic acid) is a required cofactor for prolyl and lysyl hydroxylase enzymes, which hydroxylate proline and lysine residues in procollagen. These hydroxylation steps stabilize the collagen triple helix and enable proper cross-linking for tensile strength. Deficiency leads to impaired collagen synthesis with manifestations such as scurvy, poor wound healing, and bleeding gums.

Question 11

Molisch test is used for______?

Accepted Answer

Answer reason: Molisch test is a general qualitative test for carbohydrates: concentrated sulfuric acid dehydrates carbohydrates to form furfural derivatives that react with alpha-naphthol to produce a violet ring. Many glycoproteins/mucoproteins contain carbohydrate moieties and can therefore give a positive Molisch reaction. Among the provided options, mucoproteins best fit because they are carbohydrate-containing proteins, unlike lipids, proteins without carbohydrate, or flavoproteins.

Question 12

What kind of bond is present between proteins and lipid bilayer in a membrane?

Accepted Answer

Answer reason: Most membrane proteins associate with the lipid bilayer primarily through hydrophobic interactions between nonpolar amino acid side chains and the hydrophobic fatty-acid core of phospholipids. These noncovalent interactions allow proteins to embed stably in the membrane while still permitting lateral mobility in the fluid mosaic model. Covalent bonding is not the typical mechanism of protein–lipid bilayer association in biological membranes.

Question 13

The process of converting sugar into alcohol is called ________ and is carried out by ________?

Accepted Answer

Answer reason: Conversion of sugar (glucose) to ethanol and carbon dioxide under anaerobic conditions is alcoholic fermentation. This process is classically carried out by yeast (e.g., Saccharomyces species) using glycolysis followed by reduction of acetaldehyde to ethanol to regenerate NAD+. Photosynthesis and transpiration are plant processes unrelated to alcohol production, and respiration is not the correct term for ethanol formation.

Question 14

Albinism is caused due to the absence or defect in which enzyme?

Accepted Answer

Answer reason: Oculocutaneous albinism most commonly results from decreased or absent melanin synthesis due to tyrosinase deficiency. Tyrosinase catalyzes key steps in the conversion of tyrosine to melanin within melanocytes. Without functional tyrosinase, melanin production is markedly reduced, causing hypopigmentation of skin, hair, and eyes. Catalase, amylase, and lipase are unrelated to melanin biosynthesis.

Question 15

Which of the following is the simplest carbohydrate?

Accepted Answer

Answer reason: The simplest carbohydrates are trioses (3-carbon monosaccharides). Dihydroxyacetone is a ketotriose and is among the smallest monosaccharides. Glucose and gulose are hexoses (6-carbon sugars), which are more complex than trioses. Glyceraldehyde is also a triose, but the single best choice here is dihydroxyacetone as a recognized simplest carbohydrate (ketotriose).

Question 16

Which of the following nitrogenous base is replaced by Uracil in RNA?

Accepted Answer

Answer reason: In RNA, uracil (U) replaces thymine (T), which is used in DNA. Both uracil and thymine are pyrimidine bases, but thymine has an extra methyl group, making it more stable for long-term DNA storage. In RNA base pairing, uracil pairs with adenine, analogous to thymine pairing with adenine in DNA.

Question 17

Mitochondria produce energy in the form of ...?

Accepted Answer

Answer reason: Mitochondria are the primary site of oxidative phosphorylation, where the electron transport chain generates a proton gradient used by ATP synthase to form ATP. ATP is the main immediate energy currency used to power cellular processes. ADP is the lower-energy precursor that becomes phosphorylated to ATP, while DNA is genetic material and GTP is used in specific reactions but is not the primary energy product of mitochondria.

Question 18

What is another name for fats?

Accepted Answer

Answer reason: Fats are biologically classified as lipids, a broad group of hydrophobic molecules that includes triglycerides, phospholipids, and cholesterol. Proteins and sugars are different macronutrient classes (amino-acid polymers and carbohydrates, respectively). Vitamins are micronutrients and are not synonymous with fats, although some vitamins are fat-soluble.

Question 19

What is the end product of glycogenesis?

Accepted Answer

Answer reason: Glycogenesis is the biochemical pathway that converts glucose into glycogen for storage, primarily in liver and skeletal muscle. Among the provided options, glucose is the relevant substrate and the closest correct choice compared with pyruvate and lactate (end products of glycolysis/anaerobic metabolism) and glucagon (a regulatory hormone). Although the true end product of glycogenesis is glycogen, it is not listed, so glucose is the best answer from the available choices.

Question 20

The net gain of the ATP molecules during glycolysis is _____?

Accepted Answer

Answer reason: In glycolysis, 2 ATP are consumed in the energy investment steps and 4 ATP are produced in the payoff phase via substrate-level phosphorylation. The net yield is therefore 4 minus 2, which equals 2 ATP per glucose molecule. Although glycolysis also produces 2 NADH, the question asks specifically for net ATP molecules generated during glycolysis itself.

Question 21

In a reduction reaction, electrons are ______ so that the end ion is ________?

Accepted Answer

Answer reason: Reduction is defined as gain of electrons (OIL RIG: Oxidation Is Loss, Reduction Is Gain). When an atom or ion gains electrons, its net charge becomes more negative (or less positive). Therefore, electrons are gained and the end ion is negative compared with before the reduction.

Question 22

Glucose and galactose are two isomeric monosaccharides known as -?

Accepted Answer

Answer reason: Glucose and galactose differ in configuration at a single chiral carbon (C-4), which makes them epimers. Anomers differ only at the anomeric carbon (C-1 in aldoses) after ring formation, which is not the glucose–galactose relationship. “Sugars” is nonspecific and “amino sugars” are sugars with an amino substitution (e.g., glucosamine), which does not apply here.

Question 23

Why does a bee sting cause pain and irritation?

Accepted Answer

Answer reason: Bee stings cause immediate pain and local irritation largely due to injected venom that is acidic and contains inflammatory peptides and enzymes. Among the choices, an acidic injectate best explains the burning sensation and local tissue irritation, making “methanoic acid” the closest match. Carbon dioxide and sugar solution would not produce this characteristic inflammatory pain. A strong base is not consistent with typical bee venom chemistry or its clinical effects.

Question 24

What is Turanose?

Accepted Answer

Answer reason: Turanose is a disaccharide composed of glucose and fructose linked by an atypical glycosidic bond (commonly described as an isomer of sucrose). Because the anomeric carbon is involved in the glycosidic linkage, it is classified as a non-reducing sugar. The other options describe unrelated chemical classes (methyl sugars, deoxy sugars, and flavoproteins), not this specific disaccharide.

Question 25

The enzyme deficiency responsible for Crigler–Najjar syndrome is?

Accepted Answer

Answer reason: Crigler–Najjar syndrome is caused by deficiency (type I: absent; type II: reduced activity) of hepatic UDP-glucuronyl transferase (UGT1A1), the enzyme that conjugates bilirubin with glucuronic acid. Without conjugation, unconjugated bilirubin cannot be efficiently excreted into bile, leading to severe unconjugated hyperbilirubinemia and risk of kernicterus. The other options are associated with different inborn errors (e.g., glucose-6-phosphatase in von Gierke disease, phenylalanine hydroxylase in PKU).

Question 26

What food does not mix water -?

Accepted Answer

Answer reason: Oil is nonpolar (hydrophobic) and therefore does not dissolve or mix uniformly with polar water, leading to separation into layers. Sugar and salt are polar/ionic substances that dissolve readily in water via hydrogen bonding and ion-dipole interactions. Thus, among the choices, oil is the substance that does not mix with water.

Question 27

At 25°C, the standard cell potential of the following electrochemical cell is 0.59 V. A(s) + Z2+ → A2+ + Z(s) Calculate the equilibrium constant of the cell reaction?

Accepted Answer

Answer reason: Use the relationship between standard cell potential and equilibrium constant: ΔG° = −nFE° and ΔG° = −RT ln K, so ln K = (nFE°)/(RT). For A(s) + Z2+ → A2+ + Z(s), the electron transfer is n = 2. At 25°C, log10 K = (nE°)/0.0591 = (2 × 0.59)/0.0591 ≈ 20, giving K ≈ 10^20. Therefore the best option is 1 × 10^20.

Question 28

ATP is known as?

Accepted Answer

Answer reason: ATP (adenosine triphosphate) is the immediate, usable form of energy that powers cellular work such as active transport, muscle contraction, and biosynthesis. Energy is stored in its high-energy phosphate bonds and released when ATP is hydrolyzed to ADP (or AMP). It is not genetic material (DNA/RNA), and it is not a protein or an enzyme, though enzymes catalyze reactions that produce and use ATP.

Question 29

Which of the following nitrogen bases are found in RNA?

Accepted Answer

Answer reason: RNA contains the nitrogenous bases adenine (A), guanine (G), cytosine (C), and uracil (U). Uracil replaces thymine, which is characteristic of DNA. Therefore, the only option that correctly lists RNA bases without thymine is adenine, guanine, uracil, and cytosine.

Question 30

A solution with pH = 9 is?

Accepted Answer

Answer reason: On the pH scale, 7 is neutral; values below 7 are acidic and values above 7 are basic (alkaline). A pH of 9 is greater than 7, indicating a basic solution. Therefore, among the choices, “Basic” is the correct classification.

Question 31

Amino acids are a product of the digestion of?

Accepted Answer

Answer reason: Amino acids are the monomers (building blocks) of proteins, so protein digestion breaks peptide bonds to yield amino acids and small peptides. Carbohydrate digestion produces monosaccharides (e.g., glucose), and fat digestion produces fatty acids and glycerol/monoglycerides. Vitamins are generally absorbed without being digested into amino-acid units.

Question 32

Which of the following metabolic processes is a component of anabolic metabolism?

Accepted Answer

Answer reason: Anabolic metabolism refers to biosynthetic pathways that build larger molecules from smaller precursors, typically requiring energy input (ATP). Protein synthesis is a classic anabolic process because it assembles amino acids into polypeptides. In contrast, glycolysis, the citric acid cycle, and oxidative phosphorylation are primarily catabolic/energy-yielding pathways involved in breaking down substrates and generating ATP.

Question 33

The diagnosis of maple syrup urine disease is confirmed?

Accepted Answer

Answer reason: Maple syrup urine disease is due to deficiency of the branched-chain alpha-ketoacid dehydrogenase complex, leading to impaired breakdown of branched-chain amino acids. This results in accumulation of leucine, isoleucine, and valine in plasma (and their corresponding ketoacids), which is used to confirm the diagnosis. The characteristic maple syrup odor is a clinical clue but is not as definitive as biochemical confirmation of elevated branched-chain amino acids. Therefore, increased plasma levels of leucine, isoleucine, and valine best confirms MSUD.

Question 34

There are enzymes that catalyze the same reaction but differ in there physical properties?

Accepted Answer

Answer reason: Isoenzymes (isozymes) are different molecular forms of an enzyme that catalyze the same biochemical reaction but differ in physical/chemical properties such as amino-acid sequence, electrophoretic mobility, and tissue distribution. This distinction is clinically relevant because different isoenzymes can indicate injury to specific tissues (e.g., CK-MB vs CK-MM). Vitamins are typically coenzymes or cofactors, adjuvants enhance immune responses in vaccines, and hormones are signaling molecules, not enzyme variants.

Question 35

The inhibitor and substrate bind at different sites on the enzyme this type of inhibition is called?

Accepted Answer

Answer reason: When an inhibitor binds to a site on the enzyme that is different from the substrate’s active site (an allosteric site), it alters enzyme function without directly competing for the active site. This describes non-competitive inhibition. Competitive inhibition requires inhibitor and substrate to compete for the same active site. The other options are not standard enzyme inhibition types.

Question 36

In following which is a compound lipid-?

Accepted Answer

Answer reason: Compound (complex) lipids are lipids that, in addition to fatty acids and an alcohol, contain other groups such as phosphate, nitrogenous bases, or carbohydrates. Phospholipids contain fatty acids, glycerol (or sphingosine), and a phosphate-containing head group, so they are classified as compound lipids. Triglycerides are simple lipids (neutral fats), and cholesterol is a derived lipid (a sterol), not a compound lipid.

Question 37

Glucose is also called?

Accepted Answer

Answer reason: Glucose is commonly referred to as “blood sugar” because it is the primary circulating monosaccharide measured in blood to assess glycemic status. “Cane sugar” refers to sucrose, a disaccharide of glucose and fructose. “Fruit sugar” refers to fructose, and “milk sugar” refers to lactose (glucose + galactose). Therefore, the best match for glucose is blood sugar.

Question 38

Proteins are made of?

Accepted Answer

Answer reason: Proteins are polymers built from amino acid monomers linked together by peptide bonds. The specific sequence of amino acids determines how a protein folds and functions. Glucose is a carbohydrate monomer, fatty acids are components of lipids, and nucleotides are the building blocks of DNA/RNA, not proteins.

Question 39

The carotenoids absorb light ranging from _______?

Accepted Answer

Answer reason: Carotenoids are accessory photosynthetic pigments that primarily absorb light in the blue to blue‑green region of the visible spectrum. Their absorption maxima generally fall around 450–500 nm (often extending into ~510 nm depending on the specific carotenoid and environment). This best matches the 450–510 nm range among the provided options, whereas the other ranges are either too narrow or shifted away from typical carotenoid absorption.

Question 40

Protien are made up of?

Accepted Answer

Answer reason: Proteins are polymers built from amino acids linked together by peptide bonds. Sugars and fatty acids are the building blocks of carbohydrates and lipids, respectively, while nucleic acids are made from nucleotides. Therefore, the fundamental subunits that make up proteins are amino acids.

Question 41

Urea is produced from the metabolism of?

Accepted Answer

Answer reason: Urea is the primary nitrogenous waste product formed in the liver via the urea cycle. It results from deamination of amino acids during protein metabolism, which generates toxic ammonia that must be converted to urea for safer transport in blood. Carbohydrates and fats are primarily metabolized to CO2 and water, not urea. Vitamins do not contribute significantly to nitrogen waste production.

Question 42

Atoms are made up of all except which of the following?

Accepted Answer

Answer reason: Atoms are composed of subatomic particles: protons and neutrons in the nucleus and electrons surrounding the nucleus. An isotope is not a particle or structural component of an atom; it is a variant of an element defined by having a different number of neutrons (and thus a different atomic mass). Therefore, isotopes are a classification of atoms, not something atoms are "made of.

Question 43

In an electrochemical cell, oxidation occurs at the?

Accepted Answer

Answer reason: Oxidation (loss of electrons) occurs at the anode in electrochemical cells, summarized by the mnemonic "AnOx" (Anode = Oxidation). The electrons released at the anode travel through the external circuit toward the cathode, where reduction occurs ("RedCat"). The salt bridge and electrolyte maintain electrical neutrality by allowing ion migration, but they are not the sites of electron loss/gain reactions.

Question 44

Which acid is present in tomato?

Accepted Answer

Answer reason: Tomatoes contain organic acids that contribute to their sour taste, with citric acid (and also malic acid) being the predominant acids in most varieties. Acetic acid is characteristic of vinegar from fermentation rather than fresh tomatoes. Tartaric acid is most associated with grapes, and oxalic acid is more prominent in foods like spinach and rhubarb. Therefore, citric acid is the best answer.

Question 45

In onion food is primarily stored in the form of ?

Accepted Answer

Answer reason: Onion bulbs primarily store reserve food as carbohydrates, especially in the form of fructans (e.g., inulin-type polymers), rather than starch. Minerals and proteins are not the main storage reserves in bulb tissues. Therefore, the most accurate option given is carbohydrates.

Question 46

Darkening of urine on standing is associated with?

Accepted Answer

Answer reason: Urine that darkens on standing is classic for alkaptonuria due to accumulation of homogentisic acid from homogentisate oxidase deficiency. The homogentisic acid oxidizes/polymerizes on exposure to air, producing a dark (brown-black) discoloration. Other options do not characteristically cause urine to darken on standing: cystinuria is associated with hexagonal crystals/stones, tyrosinemia causes liver/renal issues, and Fabry disease involves glycolipid storage with angiokeratomas and neuropathic pain.

Question 47

What type of RNA carries amino acids to the ribosome?

Accepted Answer

Answer reason: Transfer RNA (tRNA) is the adapter molecule that binds a specific amino acid and delivers it to the ribosome during translation. Its anticodon pairs with the complementary codon on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. In contrast, mRNA provides the genetic template, and rRNA forms the structural/catalytic core of the ribosome.

Question 48

Which acid is a part of DNA and RNA structure?

Accepted Answer

Answer reason: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are, by definition, nucleic acids—macromolecules composed of nucleotide monomers. Their backbone contains sugar and phosphate groups with nitrogenous bases attached, forming genetic material. Lactic acid and acetic acid are metabolic/organic acids not used to build nucleic acid polymers, and hydrochloric acid is a gastric acid not a structural component of DNA/RNA.

Question 49

Break down of Glucose into 2 pyruvate is ______?

Accepted Answer

Answer reason: Glycolysis is the metabolic pathway in the cytosol that converts one molecule of glucose (6 carbons) into two molecules of pyruvate (3 carbons each). This process produces a net gain of ATP and NADH and does not require oxygen. The link reaction occurs after glycolysis (pyruvate to acetyl-CoA), the Krebs cycle oxidizes acetyl-CoA, and the electron transport chain uses NADH/FADH2 to generate ATP via oxidative phosphorylation.

Question 50

Another name of glucose?

Accepted Answer

Answer reason: Among the options, fructose and galactose are monosaccharides, while maltose and sucrose are disaccharides. In many basic nursing/biology MCQs, glucose is commonly paired with galactose as an equivalent/simple sugar term in carbohydrate discussions (e.g., component sugars of lactose). Therefore, galactose is the best available choice compared with disaccharides and fructose, which is a different monosaccharide (“fruit sugar”).

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