What are co-enzymes?

What are co-enzymes? 
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Enzyme may contain a non-protein part, the coenzyme. The co-enzyme is essential for the biological activity of the enzyme. A co-enzyme is a low molecular weight organic substance, without which the enzyme cannot exhibit any reaction. Coenzyme accepts one of the products of the reaction; and so act as a co-substrate.
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Enzymes requiring NAD as co-substrate can be assayed by measuring change in absorbance at (A) 210 nm (B) 290 nm (C) 340 nm (D) 365 nm

Description : Enzymes requiring NAD as co-substrate can be assayed by measuring change in absorbance at (A) 210 nm (B) 290 nm (C) 340 nm (D) 365 nm

Last Answer : Answer : C

A demonstrable inducer is absent in (A) Allosteric enzyme (B) Constitutive enzyme (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141

Description : A demonstrable inducer is absent in (A) Allosteric enzyme (B) Constitutive enzyme (C) Inhibited enzyme (D) Co-operative enzyme ENZYMES 141

Last Answer : Answer : B

In β−oxidation of fatty acids which of the following are utilized as co-enzymes? (A) NAD+ and NADP+ (B) FAD H2 and NADH + H+ (C) FAD and FMN (D) FAD and NAD+

Description : In β−oxidation of fatty acids which of the following are utilized as co-enzymes? (A) NAD+ and NADP+ (B) FAD H2 and NADH + H+ (C) FAD and FMN (D) FAD and NAD+

Last Answer : Answer : D

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Description : What are the co-enzymes required for the reaction?

Last Answer : Biotin and ATP.

What are the co-enzymes required for the conversion of propionyl CoA to succinyl CoA?

Description : What are the co-enzymes required for the conversion of propionyl CoA to succinyl CoA?

Last Answer : Biotin, ATP, Vitamin B12.

What are the co-enzymes needed for fatty acid oxidation?

Description : What are the co-enzymes needed for fatty acid oxidation?

Last Answer : FAD and NAD.

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Description : What are the co-enzymes necessary for oxidative decarboxylation of pyruvate?

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Description : Give some examples of co-enzymes involved in reactions other than hydrogen transfer.

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Description : Give some examples of co-enzymes involved in oxidoreductases.

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Description : How are co-enzymes classified?

Last Answer : (a) Those taking part in reactions catalysed by oxidoreductases by donating or accepting hydrogen atoms or electrons. (b) Those co-enzymes taking part in reactions transferring groups other than hydrogen.

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Description : Vitamin function as a. Co-enzymes b. Co-melecules c. Building blocks of cell d. None of these

Last Answer : Ans: C

Boron in green plants assists in (a) activation of enzymes (b) acting as enzyme co-factor (c) photosynthesis (d) sugar transport.

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Last Answer : (d) sugar transport.

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Last Answer : (b) they (prosthetic groups) are tightly bound to apoenzymes

The major role of minor elements inside living organisms is to act as (a) co-factors of enzymes (b) building blocks of important amino acids (c) constituent of hormones (d) binder of cell structure.

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Last Answer : (a) co-factors of enzymes

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Last Answer : (1) Holoenzyme = Apoenzyme + Coenzyme

Substance which increase the activity of certain enzymes called (a) Pro-enzyme (b) Iso-enzymes (d) Co-enzymes (d) Catalysis

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Last Answer : c

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Last Answer : Answer : C

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Last Answer : Answer : C

All the enzymes required for de novo synthesis of pyrimidine nucleotides are cytosolic except (A) Carbamoyl phosphate synthetase (B) Aspartate transcarbamoylase (C) Dihydro-orotase (D) Dihydro-orotate dehydrogenase

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Last Answer : Answer : A

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In conversion of lactic acid to glucose, three reactions of glycolytic pathway are circumvented, which of the following enzymes do not participate? (A) Pyruvate carboxylase (B) Phosphoenol pyruvate carboxy kinase (C) Pyruvate kinase (D) Glucose-6-phosphatase

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The enzymes present in the membrane of mitochondria are (A) Flavoproteins and cytochromes (B) Fumarase and lipase (C) Enolase and catalase (D) Hexokinase and zymase

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Enzymes functional in cell or mitochondria are (A) Endoenzymes (B) Exoenzymes (C) Apoenzymes (D) Holoenzymes

Description : Enzymes functional in cell or mitochondria are (A) Endoenzymes (B) Exoenzymes (C) Apoenzymes (D) Holoenzymes

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In cell, digestive enzymes are found mainly in (A) Vacuoles (B) Lysosomes (C) Ribosomes (D) Lomasomes

Description : In cell, digestive enzymes are found mainly in (A) Vacuoles (B) Lysosomes (C) Ribosomes (D) Lomasomes

Last Answer : Answer : B

Out of the total enzymes present in a cell, a mitochondrion alone has (A) 4% (B) 70% (C) 95% (D) 50%

Description : Out of the total enzymes present in a cell, a mitochondrion alone has (A) 4% (B) 70% (C) 95% (D) 50%

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The best example of extracellular enzymes (exoenzyme) is (A) Nucleases (B) Digestive enzymes (C) Succinic dehydrogenase (D) None of these

Description : The best example of extracellular enzymes (exoenzyme) is (A) Nucleases (B) Digestive enzymes (C) Succinic dehydrogenase (D) None of these

Last Answer : Answer : C

The fruit when kept is open, tastes bitter after 2 hours because of (A) Loss of water from juice (B) Decreased concentration of fructose in juice (C) Fermentation by yeast (D) Contamination by bacterial enzymes

Description : The fruit when kept is open, tastes bitter after 2 hours because of (A) Loss of water from juice (B) Decreased concentration of fructose in juice (C) Fermentation by yeast (D) Contamination by bacterial enzymes

Last Answer : Answer : D

Who got Nobel Prize in 1978 for working on enzymes? (A) Koshland (B) Arber and Nathans (C) Nass and Nass (D) H.G. Khorana

Description : Who got Nobel Prize in 1978 for working on enzymes? (A) Koshland (B) Arber and Nathans (C) Nass and Nass (D) H.G. Khorana

Last Answer : Answer : A

Which is not true about inorganic catalysts and enzymes? (A) They are specific (B) Inorganic catalysts require specific not needed by enzymes (C) They are sensitive to pH (D) They speed up the rate of chemical reaction

Description : Which is not true about inorganic catalysts and enzymes? (A) They are specific (B) Inorganic catalysts require specific not needed by enzymes (C) They are sensitive to pH (D) They speed up the rate of chemical reaction

Last Answer : Answer : B

Coenzyme is (A) Often a vitamin (B) Always an inorganic compound (C) Always a protein (D) Often a metal ENZYMES 173

Description : Coenzyme is (A) Often a vitamin (B) Always an inorganic compound (C) Always a protein (D) Often a metal ENZYMES 173

Last Answer : Answer : A

Template/lock and key theory of enzyme action is supported by (A) Enzymes speed up reaction (B) Enzymes occur in living beings and speed up certain reactions (C) Enzymes determine the direction of reaction (D) Compounds similar to substrate inhibit enzyme activity

Description : Template/lock and key theory of enzyme action is supported by (A) Enzymes speed up reaction (B) Enzymes occur in living beings and speed up certain reactions (C) Enzymes determine the direction of reaction (D) Compounds similar to substrate inhibit enzyme activity

Last Answer : Answer : D

Dry seeds endure higher temperature than germinating seeds as (A) Hydration is essential for making enzymes sensitive to temperature (B) Dry seeds have a hard covering (C) Dry seeds have more reserve food (D) Seedlings are tender

Description : Dry seeds endure higher temperature than germinating seeds as (A) Hydration is essential for making enzymes sensitive to temperature (B) Dry seeds have a hard covering (C) Dry seeds have more reserve food (D) Seedlings are tender

Last Answer : Answer : A

Enzymes, vitamins and hormones are common in (A) Being proteinaceous (B) Being synthesized in the body of organisms (C) Enhancing oxidative metabolism (D) Regulating metabolism

Description : Enzymes, vitamins and hormones are common in (A) Being proteinaceous (B) Being synthesized in the body of organisms (C) Enhancing oxidative metabolism (D) Regulating metabolism

Last Answer : Answer : D

Enzymes are different from catalysts in (A) Being proteinaceous (B) Not used up in reaction (C) Functional at high temperature (D) Having high rate of diffusion

Description : Enzymes are different from catalysts in (A) Being proteinaceous (B) Not used up in reaction (C) Functional at high temperature (D) Having high rate of diffusion

Last Answer : Answer : A

In plants, enzymes occur in (A) Flowers only (B) Leaves only (C) All living cells (D) Storage organs only

Description : In plants, enzymes occur in (A) Flowers only (B) Leaves only (C) All living cells (D) Storage organs only

Last Answer : Answer : C