Question 1

Which of the following is an example of a chromoprotein?

Accepted Answer

Answer reason: Hemoglobin is a chromoprotein because it contains a heme group with an iron-containing porphyrin ring that gives it color and allows it to bind oxygen. Chromoproteins are conjugated proteins with a colored prosthetic group, typically a pigment such as heme.

Question 2

Number of carbons in tetroses are ________________?

Accepted Answer

Answer reason: Tetroses are monosaccharides that contain four carbon atoms; the prefix “tetra-” means four, so the correct number of carbons in a tetrose is 4.

Question 3

Polysaccharides are?

Accepted Answer

Answer reason: Polysaccharides are long-chain carbohydrates composed of repeating monosaccharide units linked by glycosidic bonds, making them biological polymers such as starch, glycogen, and cellulose.

Question 4

The number of isomers of glucose is?

Accepted Answer

Answer reason: Glucose is an aldohexose with four chiral centers, and the number of possible stereoisomers is determined by the formula 2ⁿ, where n is the number of chiral carbons. Therefore, 2⁴ = 16 stereoisomers, making 16 the correct answer.

Question 5

The protein present in hair is?

Accepted Answer

Answer reason: Keratin is the primary structural protein found in hair, composed of fibrous alpha-helical polypeptides rich in cysteine, which form strong disulfide bonds that provide rigidity and resilience.

Question 6

Glucose is .....carbon compound?

Accepted Answer

Answer reason: Glucose contains six carbon atoms, making it a hexose sugar. Its chemical formula is C₆H₁₂O₆, confirming that it is a 6-carbon compound.

Question 7

Example of keto sugar is ………?

Accepted Answer

Answer reason: Fructose is a keto sugar because it contains a ketone functional group at the second carbon, classifying it as a ketohexose. In contrast, glucose, galactose, and mannose are aldo sugars with an aldehyde group.

Question 8

The Symbol of Glutamate is?

Accepted Answer

Answer reason: The single-letter symbol for glutamate is E, while Q represents glutamine. The single-letter amino acid codes are standardized based on nomenclature and structural distinctions, making E the correct symbol for glutamate.

Question 9

2nd shell has _________ numbers of electrons?

Accepted Answer

Answer reason: The second electron shell (n=2) can hold a maximum of 8 electrons because it contains one 2s orbital (2 electrons) and three 2p orbitals (6 electrons), giving a total capacity of 8.

Question 10

An example of chromoprotein is?

Accepted Answer

Answer reason: Hemoglobin is a chromoprotein because it contains a heme prosthetic group with an iron-containing porphyrin ring that imparts color and enables oxygen binding. Chromoproteins are conjugated proteins associated with a colored pigment such as heme.

Question 11

The simplest amino acids are?

Accepted Answer

Answer reason: Glycine is the simplest amino acid because its side chain consists of a single hydrogen atom, making it the smallest and least structurally complex of all amino acids. This minimal structure allows greater flexibility within protein chains.

Question 12

The sugar found in RNA is?

Accepted Answer

Answer reason: RNA contains D-ribose with a 2′-OH group; DNA contains 2′-deoxyribose. The other listed sugars are not constituents of RNA.

Question 13

Net ATPs used in aerobic glycolysis are ______?

Accepted Answer

Answer reason: In aerobic glycolysis, net substrate-level ATP gain is 2 and 2 NADH are formed. Using the classical P/O ratio (3 ATP per cytosolic NADH via shuttle), total ATP equivalents are 2 + 6 = 8

Question 14

Uracil and ribose form?

Accepted Answer

Answer reason: A nucleoside is a base plus ribose. Pyrimidines take the -idine suffix; uracil + ribose is uridine. Adenosine and guanosine are purine nucleosides; cytidine is cytosine + ribose

Question 15

The sugar found in DNA is?

Accepted Answer

Answer reason: DNA contains deoxyribose as its pentose sugar; ribose is found in RNA, and xylose/ribulose are not DNA components.

Question 16

Starch is a?

Accepted Answer

Answer reason: Starch consists of many glucose units (amylose and amylopectin) and is therefore a polysaccharide.

Question 17

Casein, the milk protein is?

Accepted Answer

Answer reason: Casein contains covalently bound phosphate groups and forms calcium–phosphate micelles; it is classified as a phosphoprotein

Question 18

Cofactor is ....... part of holoenzyme?

Accepted Answer

Answer reason: A holoenzyme consists of an apoenzyme plus a non-protein component. The inorganic non-protein component (often a metal ion) is termed a cofactor; the organic non-protein component is a coenzyme.

Question 19

The one alphabet symbol of Arginine is ......?

Accepted Answer

Answer reason: Arginine’s standard one-letter amino acid code is R; W is tryptophan, K is lysine, and Q is glutamine.

Question 20

Tripeptide is a chain having ...... amino acid?

Accepted Answer

Answer reason: A tripeptide consists of three amino acids linked by peptide bonds.

Question 21

K is the symbol of .......?

Accepted Answer

Answer reason: In standard one-letter amino acid codes, K denotes lysine. Leucine is L, and glutamic acid is E.

Question 22

Each turn of α-helix contains the amino acid residues (number)?

Accepted Answer

Answer reason: An α-helix has 3.6 amino acid residues per turn (pitch ~5.4 Å), making 3.6 the correct number.

Question 23

F is the symbol of .......?

Accepted Answer

Answer reason: The one-letter amino acid code F denotes phenylalanine. Methionine is M, tyrosine is Y, and histidine is H.

Question 24

The carbohydrate reserved in human body is?

Accepted Answer

Answer reason: Humans store carbohydrates as glycogen in the liver and skeletal muscle. Starch and inulin are plant storage polysaccharides, and glucose is a circulating monosaccharide rather than a storage form.

Question 25

Which of the following is polysaccharide?

Accepted Answer

Answer reason: Agar is a complex polysaccharide from red algae; lactose and sucrose are disaccharides, and insulin is a peptide hormone.

Question 26

Enzymes that catalyze electron transport are present mainly in the?

Accepted Answer

Answer reason: The electron transport chain complexes and ATP synthase are embedded in the inner mitochondrial membrane, where oxidative phosphorylation occurs.

Question 27

An example of Aldo sugar is...?

Accepted Answer

Answer reason: An aldo sugar (aldose) contains an aldehyde group; glucose is an aldose. Fructose is a ketose, and chitin and cellulose are polysaccharides.

Question 28

An example of a saturated fatty acid is?

Accepted Answer

Answer reason: Palmitic acid is a fully saturated 16-carbon fatty acid; the others (oleic, linoleic, and erucic) are unsaturated.

Question 29

Which of the following is a proteinaceous substance?

Accepted Answer

Answer reason: Starch is a polysaccharide (carbohydrate), not a protein. Note that heparin (a glycosaminoglycan) and glycogen (a polysaccharide) are also not proteins, whereas amyloid is proteinaceous.

Question 30

A process in which an electron is lost is called __________?

Accepted Answer

Answer reason: The loss of electrons is oxidation (OIL RIG: Oxidation Is Loss, Reduction Is Gain).

Question 31

In which of the following cells does the Krebs cycle not occur?

Accepted Answer

Answer reason: The Krebs (TCA) cycle occurs in the mitochondria. Mature red blood cells lack mitochondria, so they cannot perform the Krebs cycle and rely on anaerobic glycolysis. Neurons, type II alveolar cells, and epithelial cells contain mitochondria.

Question 32

Which of the following polysaccharides is indigestible by man?

Accepted Answer

Answer reason: Humans lack the enzyme cellulase to hydrolyze the beta-1,4-glycosidic bonds in cellulose, making it indigestible. Amylopectin, glycogen, and amylose are digestible starches with alpha linkages.

Question 33

A proton has a ________ charge?

Accepted Answer

Answer reason: A proton carries a +1 elementary charge; electrons are negative, and neutrons are neutral.

Question 34

An enzyme that catalyses the conversion of an aldose sugar to a ketose sugar would be classified as one of the following?

Accepted Answer

Answer reason: Aldose-to-ketose conversion is an intramolecular rearrangement (isomerization); enzymes that catalyze it are isomerases, e.g., aldose–ketose isomerases.

Question 35

Where is glycogen stored?

Accepted Answer

Answer reason: Glycogen is stored primarily in the liver and skeletal muscle; the stomach and kidneys are not major glycogen stores.

Question 36

What is the main product of protein metabolism?

Accepted Answer

Answer reason: Amino acid deamination generates ammonia, which is converted in the liver to urea—the principal nitrogenous waste of protein metabolism.

Question 37

Which type of enzyme brings about intermolecular rearrangement of atoms in molecules?

Accepted Answer

Answer reason: Isomerases catalyze intramolecular rearrangements, converting a molecule into one of its isomers. Lyases add or remove groups to form double bonds, hydrolases catalyze hydrolysis, and transfer enzymes move groups between molecules.

Question 38

An enzyme increases the rate of a reaction by ........ activation energy?

Accepted Answer

Answer reason: Enzymes accelerate reactions by lowering the activation energy, typically by stabilizing the transition state.

Question 39

A positive Benedict's test is not given by?

Accepted Answer

Answer reason: Benedict’s test detects reducing sugars. Glucose, lactose, and maltose are reducing sugars, while sucrose is nonreducing because both anomeric carbons are involved in its glycosidic bond.

Question 40

An alpha helix is formed where the highest probability of ........ sequence is present?

Accepted Answer

Answer reason: Alpha-helical segments are favored by the amino acids methionine, alanine, leucine, glutamate, and lysine (MALEK). Among the choices, MALE best represents this high helix-forming propensity.

Question 41

The primary structure of a protein is formed by?

Accepted Answer

Answer reason: The primary structure is the linear sequence of amino acids linked by peptide bonds; hydrogen bonds and disulfide bonds stabilize higher-order structures.

Question 42

The most important epimers of glucose are?

Accepted Answer

Answer reason: Glucose and galactose differ in configuration at C-4, making galactose the key epimer of glucose; fructose is a ketose, and arabinose and xylose are pentoses.

Question 43

Α-D-glucose and β-D-glucose are related by?

Accepted Answer

Answer reason: α- and β-D-glucose are cyclic forms that differ only in the configuration at the anomeric carbon (C1), making them anomers.

Question 44

Account for the net production of ATP at each step of cellular respiration for one molecule of glucose?

Accepted Answer

Answer reason: Net ATP per glucose: glycolysis yields 2 ATP, the citric acid cycle yields 2 ATP (as GTP), and oxidative phosphorylation contributes about 32 ATP, totaling ~36. This matches option A.

Question 45

What is the energy currency of the cell called?

Accepted Answer

Answer reason: ATP (adenosine triphosphate) stores and transfers energy for cellular processes; ADP has one fewer phosphate and less energy, and RNA and DNA are nucleic acids, not primary energy carriers.

Question 46

Sickle cell anemia is due to the replacement of glutamic acid with which amino acid?

Accepted Answer

Answer reason: In sickle cell disease, a missense mutation in the β-globin gene substitutes nonpolar valine for negatively charged glutamic acid at position 6 of the β chain.

Question 47

All proteins contain the?

Accepted Answer

Answer reason: Proteins are polymers built from the common set of 20 standard amino acids, even though many other amino acids exist in nature.

Question 48

The carbohydrate of the blood group substances is?

Accepted Answer

Answer reason: ABO blood group antigens are oligosaccharides that characteristically contain L-fucose as a terminal sugar.

Question 49

A polysaccharide that is often called animal starch is?

Accepted Answer

Answer reason: Glycogen is the storage polysaccharide in animals, commonly called animal starch, stored mainly in the liver and muscles.

Question 50

C-O-C is a functional group of _____________?

Accepted Answer

Answer reason: The ether functional group consists of an oxygen atom bonded to two carbon atoms (C–O–C).

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