Biomolecules Test

Result

Biomolecules Test - 44

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Coenzyme among the following is

A
Mg$$^{++}$$

B
A part of sRNA

C
A part of tRNA

D
FMN

Solution

Some enzymes require no chemical groups other than their amino acid residues for activity. Others require an additional chemical component called as a cofactor. The cofactor can be either one or more inorganic ions such as ferrous, divalent magnesium or divalent manganese and zinc ions or a complex organic or metallo-organic molecule called as a coenzyme, e.g., FMN or flavin mononucleotide, which transfers electrons in biochemical reactions and is derived from riboflavin or vitamin B$$_{2}$$.
So, the correct answer is option D.
Question 2
1 / -0

A distinct domain in an enzyme molecule may

A
Contribute to catalytic site

B
Bind a coenzyme

C
Bind an allosteric effector

D
All of the above

Solution

A distinct domain in an enzyme molecule may be a catalytic site, allosteric site that binds to the cofactor to form holoenzyme
So, the correct answer is 'All of the above'
Question 3
1 / -0

The term 'feed back' refers to the effect of

A
Substrate on the rate of enzymatic reaction

B
End products on the rate of enzymatic reaction

C
Enzyme concentration on its rate of reaction

D
An external compound on the rate of enzymatic reactions

Solution

Feedback mechanism is a regulatory mechanism for the enzyme action where the end product inhibits the action of the enzyme when its concentration exceeds the need of the cell. This helps to maintain the homeostasis.
So, the correct answer is option B.
Question 4
1 / -0

..................... is called as inactive precursor of an enzyme.

A
Apoenzyme

B
Proenzyme

C
Zymogen

D
Both B and C

Solution

Activation of an enzyme by proteolytic cleavage is a type of regulatory mechanism. An inactive precursor of the enzyme called as zymogen, is cleaved to form the active enzyme. Many proteolytic enzymes of the stomach and pancreas are regulated this way. Another term used for zymogens is proenzyme. Proenzymes are inactive precursors of the enzyme.
Question 5
1 / -0

Which among the following are essential chemical components of many coenzymes?

A
Nucleic acids

B
Carbohydrates

C
Vitamins

D
Proteins

Solution

Enzymes are simple if they are made up of only proteins example pepsin, amylase etc. while conjugate enzymes have an additional non protein organic coenzyme or inorganic cofactor. Loosely attached organic cofactors are called as coenzymes example NAD, FAD TPP etc. Coenzymes are generally derived from vitamins like Thiamine (TPP), Riboflavin (FMN, FAD), Niacin (NAD), Pantothenate (CoA).
Question 6
1 / -0

What is the meaning of turnover with reference to enzyme?

A
The number of substrate molecules that molecule of an enzyme converts into products per minute.

B
The number of substrate molecules that molecule of an enzyme converts into products per day.

C
The number of substrate molecules that molecule of an enzyme converts into products per hour.

D
The number of substrate molecules that molecule of an enzyme converts into products per second.

Solution

Turn over number of enzymes is used to compare rates of enzyme catalyzed reactions. It is defined as number of substrate molecules converted into product molecules per unit time (minute).
Question 7
1 / -0

Which of the following statement is incorrect for maximum velocity (V$$_{max}$$) of an enzyme catalysed reaction?

A
It is not a fundamental property of an enzyme, since it is dependent on the initial enzyme loading.

B
It is measured for the purpose of enzyme assay.

C
It can be converted into the reaction velocity at a lower substrate concentration.

D
It can be used to deduce the number of active catalytic sites per enzyme molecule.

Solution

V$$_{max}$$ or maximum velocity of enzyme catalyzed reaction is a fundamental characteristic of enzyme. It depends on the number of active sites in enzymes and can be directly correlated with the substrate concentration at lower substrate concentration. In other words, at low substrate concentration, the V$$_{max}$$ of a reaction will increase with the concentration of substrate molecules till all the available active sites are saturated with the substrate molecules. However, it is difficult to exactly calculate V$$_{max}$$. Hence, V$$_{max}$$ is not a measure for the purpose of enzyme assay. It is usually deduced graphically. The reaction rate is measured at different substrate concentration and a graph is drawn. From the graph, V$$_{max}$$ and optimum substrate concentration can be deduced.
Therefore, the correct answer is option B.
Question 8
1 / -0

K$$_m$$ of enzyme is

A
The substrate concentration at 1/2 of maximum velocity of enzyme action.

B
The substrate concentration at maximum velocity of enzyme action.

C
Half of maximum velocity of enzyme at unit substrate concentration at infinite velocity of enzyme action.

D
Substrate concentration at infinite velocity of enzyme action.

Solution

The Michaelis Menten constant is the substrate concentration at which the reaction rate is one half the maximum. The K$$_m$$ describes the affinity of enzyme for a substrate molecule. Greater the affinity lower is the K$$_m$$ value and sooner the V$$_{max}$$ can be attained and vice versa.
Question 9
1 / -0

Solve the following.
It is known that 5 microgram of an enzyme convert 10 million molecules of substrate to end products per second. To calculate the enzyme's turnover what else must be known?

A
Molecular weight of the enzyme.

B
Molecular weight of the enzyme and substrate both.

C
The molecular weight of substrate only.

D
Molecular weight of end product only.

Solution

Turnover number (also termed k$$_{cat}$$) is defined as the maximum number of molecules of substrate that an enzyme can convert to product per unit of time (a turnover rate). Here, available weight of enzyme is given but number of enzyme molecules is not known. If we know the molecular weight of the enzyme we can do calculations in terms of moles using the formula; number of moles is equal to the weight in grams/molecular weight.
Question 10
1 / -0

During the germination of castor seeds, the activity of ................. is very high.

A
$$\alpha$$-amylase

B
$$\beta$$-amylase

C
Protease

D
Lipase

Solution

During the germination of castor seeds, the activity of $$\alpha$$-amylase enzyme is very high. Amylase is a protein enzyme that hydrolyses $$\alpha$$-bonds of large, $$\alpha$$-linked polysaccharides, such as starch and glycogen, yielding glucose and maltose. It is the major form of amylase found in humans and other mammals. It is also present in seeds containing starch as a food reserve, and is secreted by many fungi.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Biomolecules Test - 44

Result

Biomolecules Test - 44

Score

-

Rank

-

SHARING IS CARING

Question 1

Mg$$^{++}$$

A part of sRNA

A part of tRNA

FMN

Solution

Question 2

Contribute to catalytic site

Bind a coenzyme

Bind an allosteric effector

All of the above

Solution

Question 3

Substrate on the rate of enzymatic reaction

End products on the rate of enzymatic reaction

Enzyme concentration on its rate of reaction

An external compound on the rate of enzymatic reactions

Solution

Question 4

Apoenzyme

Proenzyme

Zymogen

Both B and C

Solution

Question 5

Nucleic acids

Carbohydrates

Vitamins

Proteins

Solution

Question 6

The number of substrate molecules that molecule of an enzyme converts into products per minute.

The number of substrate molecules that molecule of an enzyme converts into products per day.

The number of substrate molecules that molecule of an enzyme converts into products per hour.

The number of substrate molecules that molecule of an enzyme converts into products per second.

Solution

Question 7

It is not a fundamental property of an enzyme, since it is dependent on the initial enzyme loading.

It is measured for the purpose of enzyme assay.

It can be converted into the reaction velocity at a lower substrate concentration.

It can be used to deduce the number of active catalytic sites per enzyme molecule.

Solution

Question 8

The substrate concentration at 1/2 of maximum velocity of enzyme action.

The substrate concentration at maximum velocity of enzyme action.

Half of maximum velocity of enzyme at unit substrate concentration at infinite velocity of enzyme action.

Substrate concentration at infinite velocity of enzyme action.

Solution

Question 9

Molecular weight of the enzyme.

Molecular weight of the enzyme and substrate both.

The molecular weight of substrate only.

Molecular weight of end product only.

Solution

Question 10

$$\alpha$$-amylase

$$\beta$$-amylase

Protease

Lipase

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.