MCQS | Ascorbic acid acts as an

Question :- In aerobic respiration, the compound that enters a mitochondrion is

1.acetyl CoA

2.pyruvate

3. phosphoglyceraldehyde

4.oxaloacetate

Question :- What metal ion is specifically bound by vitamin B12?

1.Cobalt

2.Copper

3.Zinc

4.Iron

Question :- Biotin occurs mainly in combined forms bound to protein through

1.ε-N-lysine moiety

2.ε-S-lysine moiety

3. ε-N-biotinyl-L-lysine

4.ε-N-lipoyl - L-lysine

Question :- β-carotene together with α-carotene, γ-carotene and cryptoxanthine are synthesized by

1.plants

2.animal

3.plants and animals both

4.none of these

Question :- In electron transport, electrons ultimately pass to

1.ADP

2. cytochrome b

3.oxygen

4.none of these

Question :- Lipoic acid exists in

1.oxidized form

2.reduced form

3.oxidized and reduced form both

4.none of these

Question :- Selenium is an essential component of the enzyme glutathione peroxidase which

1.scavenges toxic hydoperoxycompounds in tissues

2.reduces toxic hydoperoxycompounds in tissues

3.oxidizes toxic hydoperoxycompounds in tissues

4. none of the above

Question :- What compound of raw egg white causes a syndrome similar to vitamin B deficiency?

1.Avidin

2.Betabindin

3.Ovalbumin

4.Albumin

Question :- A deficiency of niacin causes

1.pellagra

2.scurvy

3.cataract

4.anemia

Question :- A deficiency of thiamin produces the disease known as

1. beri-beri

2.scurvy

3.cataract

4.anemia

Question :- A deficiency of Vitamin K results in a decreased level of

1.prothrombin

2.thrombin

3.fibrin

4.fibrinogen

Question :- A fat-soluble vitamin that regulates blood clotting is

1. vitamin A

2. vitamin K

3. vitamin C

4.niacin

Question :- Acyl carrier protein (ACP) plays an important role in the biosynthesis

1.fatty acids

2.amino acids

3.sugars

4.carbohydrates

Question :- An early sign of retinol deficiencies in man is

1.night blindness

2.keratinization

3.xeropthalmia

4. none of these

Question :- An enzyme, L-folate reductase reduces folic acid to

1. hydrofolic acid

2.dihydrofolic acid

3.trihydrofolic acid

4.tetrahydrofolic acid

Question :- An example of a digestive hormone is

1.lipase

2.pepsin

3.amylase

4.gastrin

Question :- Ascorbic acid acts as an

1.reducing agent

2.oxidizing agent

3.oxidizing and reducing agent both

4.none of the above

Question :- Biotin occurs mainly in combined forms bound to protein through

1.ε-N-lysine moiety

2. ε-S-lysine moiety

3.ε-N-biotinyl-L-lysine

4.ε-N-lipoyl - L-lysine

Question :- Dihydroorotate dehydrogenase contains

1.4 flavins and 4 atoms of iron per molecule

2.2 flavins and 4 atoms of iron per molecule

3.2 flavins and 2 atoms of iron per molecule

4.4 flavins and 2 atoms of iron per molecule

Question :- During electron transport, protons are pumped out of the mitochondrion at each of the major sites except for

1.complex I

2.complex II

3.complex III

4.complex IV

Question :- E.coli ACP has its molecular weight as around

1.9000

2.19000

3.39000

4.90,000

Question :- How many CO2 molecules are exhaled for each O2 molecule utilized in cellular respiration?

1.1

2.3

3.6

4.12

Question :- How many molecules of ATP are hydrolysed to form two molecule of ammonia?

1.10

2.5

3.16

4.15

Question :- Which of the following is not a significant biological oxidizing agent?

1.FAD

2.Fe3+

3.O2

4.NAD+

Question :- β-carotene together with α-carotene, γ-carotene and cryptoxanthine are synthesized by

1.plants

2.animal

3.plants and animals both

4.none of these

Question :- In one iron-metalloflavoprotein, the iron is present as a

1.heme-protein

2.nonheme type

3.both (a) and (b)

4.flavin moiety

Question :- In the co-enzyme B12the position occupied by a cyanide ion in vitamin B12 is bonded directly to the __________ of the ribose of adenosine.

1.adenine

2. 5-6 dimethylbenzimidazole

3.hydroxycobalamin

4.cyanocobalamin

Question :- Lactic acid is produced by human muscles during strenuous exercise because of lack of

1.oxygen

2.NAD+

3.glucose

4.ADP and Pi

Question :- Lipoic acid is a co-factor of the

1.pyruvic dehydrogenase

2.α-ketoglutaric dehydrogenase

3.both (a) and (b)

4. di-hydroorotate dehydrogenase

Question :- Lipoic acid is a co-factor of the

1.pyruvic dehydrogenase

2.α-ketoglutaric dehydrogenase

3.both (a) and (b)

4.di-hydroorotate dehydrogenase

Question :- Main function of insulin hormone is to

1.increase glycogen in liver

2.decrease glycogen in liver

3.increase blood sugar

4.decrease blood sugar

Question :- Models of end-linked Osaka VI Fibrinogen dimers, a bilayer dimer is linked at

1.both ends by one disulfide bond

2.either end via two disulfide bonds

3.either end via a single disulfide bond

4.both ends by two disulfide bonds

Question :- Molar absorbtivities of compounds exhibiting charge transfer absorption are

1.small

2.moderate

3.large

4.none of these

Question :- Nitrate reduction can be carried out by

1.only microorganism

2.plant and microorganism

3.only plants

4.none of these

Question :- The absence of ascorbic acid in the human diet gives rise to

1.rickets

2.pernicious anemia

3.cataract

4. beri-beri

Question :- The aerobic breakdown of glucose known as respiration involves

1.electron transport phosphorylation

2.glycolysis

3.Krebs Cycle

4.all of the above

Question :- The complete oxidation of glucose yields usable energy in the form of

1.FADH2

2.coenzyme A

3.ATP

4.pyruvic acid

Question :- The disease Beriberi is due to a dietary deficiency in

1.vitamin B1 (thiamine)

2.vitamin B2 (riboflavin)

3.vitamin B6 (pyridoxine)

4.vitamin B12

Question :- The inputs to one cycle of the urea cycle are

1.1 molecule of aspartic acid, 1 molecule of ammonia, 1 molecule of carbon dioxide, 3 molecules of ATP

2.1 molecule of urea, 1 molecule of ammonia, 3 molecules of ATP and 1 molecule of fumaric acid

3.1 molecule of fumaric acid, 1 molecule of urea, 3 molecules of AMP

4.None of the above

Question :- The most prominent role that tocopherol has in in-vitro systems is as a strong

1.antioxidants

2. reducing agent

3.oxidizing agent

4. all of these

Question :- The most prominent role that tocopherol has in in-vitro systems is as a strong

1.antioxidants

2.reducing agent

3.oxidizing agent

4.all of these

Question :- The nitrogen atoms of urea produced in the urea cycle are derived from

1.nitrate

2.ammonia and aspartic acid

3.nitrite

4.ammonia

Question :- The occurrence of metals such as iron or molybdenum in some flavoproteins can

1.stabilize the semiquinone

2.de-stabilize the semiquinone

3.form chelation

4.all of these

Question :- The products of urea cycle are

1.1 molecule of urea, 1 molecule of ammonia, 1 molecule of ATP and 1 molecule of fumaric acid

2.1 molecule of fumaric acid, 1 molecule of urea, 1 molecule of AMP, 2 molecules of ADP

3. 1 molecule of aspartic acid, 1 molecule of ammonia, 1 molecule of fumaric acid, 1 molecule of ATP

4.None of the above

Question :- The prosthetic group biotin is a carrier of which type of molecule?

1.Activated carbon dioxide (CO2)

2.Ammonia

3.Methyl group

4.Sulfhydryl group

Question :- The reductant, NADH, transfers the electrons via a flavo-proteins to the specific disulfide (S-S) protein to form a dithiol (SH,SH) protein which converts vitamin

1.B12(Co2+)to B12(Co)

2. B12(Co) to B12(Co2+)

3.B12(Co2+)to B12(Co+)

4.B12(Co+)to B12(Co2+)

Question :- The symptoms of retinol excess are

1. bone fragility

2.nausea

3.weakness

4.all of these

Question :- The vitamin niacin is part of the __________ molecule.

1.ferredoxin

2.pyridoxal phosphate

3.pyrophosphate

4.NAD+

Question :- The vitamin riboflavin is part of the __________ molecule.

1.ferredoxin

2.FAD

3.pyridoxal phosphat

4.pyrophosphate

Question :- The vitamin riboflavin, which occurs as a yellow pigment in egg yolk and milk become

1.colorless on reduction with Zn in acid and regained its color on re-oxidation

2.colorless on oxidation and regained its color on reduction with Zn in acid

3.more deep in color on reduction with Zn in acid and regained its color on re-oxidation

4.more deep in color on oxidation and regained its color on reduction with Zn in acid

Question :- Urea cycle converts

1.ammonia into a less toxic form

2.ketoacids into amino acids

3.amino acids into ketoacids

4.none of these

Question :- Vitamin B12 (Cobalamin) is only synthesized by

1.fishes

2.micro-organisms

3.plants

4.animals

Question :- Vitamin B12 is useful in the prevention and treatment of

1.pernicious anemia

2.scurvy

3.cataract

4.beri-beri

Question :- Vitamin K1 was first isolated from alfalalfa and has the phytyl side chain consisting of

1.four isoprene units

2.six isoprene units

3.nine isoprene units

4.four isoprene units

Question :- Vitamin-C is considered as a

1. water soluble

2.fat soluble

3.fat and water soluble

4. none of these

Question :- Vitamin-D deficiency can cause

1.rickets

2.pernicious anemia

3.cataract

4. beri-beri

Question :- Vitamins are essential because the organism

1.can't synthesize these compounds at all

2. can synthesize these compounds partially

3.can't synthesize these compounds in the adequate amounts

4.none of the above

Question :- What happens after glycolysis when oxygen is available as an electron acceptor?

1. Pyruvate is formed

2. NADH is produced

3.Fermentation

4.Oxidative phosphorylation

Question :- Which of the following amino acid do not fall under the category of essential amino acid?

1.Histidine

2.Leucine

3.Glycine

4.Methionine

Question :- Which of the following are reduced coenzymes?

1.NADH and FADH2

2.NAD+ and FAD

3.ATP and GTP

4.Coenzyme A and ubiquinone

Question :- Which of the following compounds/(s) belong/(s) to the vitamin B6 group?

1.Pyridoxal

2.Pyridoxine

3.Pyridoxamine

4.All of these

Question :- Which of the following is correct sequence of processes in the oxidation of glucose?

1.Krebs cycle - glycolysis - electron transport

2.Glycolysis - Krebs cycle - eletron transport

3.Electron transport - Krebs cycle - glycolysis

4.Krebs cycle - electron transport - glycolysis

Question :- Which of the following is used as carbon atom source while producing urea in the urea cycle?

1.Arginine

2.Aspartic acid

3.Carbon dioxide

4.Glucose

Question :- Which of these hormones is a catecholamine?

1.Follitropin

2.Norepinephrine

3.Tetraiodothyronine

4.Tetrahydrofolate

Question :- Which of these is a symptom of vitamin A deficiency?

1.Osteoporosis

2. Impaired taste perception

3.Blindness

4.Impaired blood clotting

Question :- Which of these is a vitamin A precursor?

1.Cobalamin

2.Pyridoxine

3.Beta-Carotene

4.Thiamine

Question :- Which of these molecules is vitamin H?

1.Biotin

2.Carnitine

3.Folic acid

4.None of these

Question :- Who discovered vitamin C (ascorbic acid)?

1. Paul Berg

2.Linus Pauling

3.Albert Szent-Gyorgyi

4.Kerry Mull is