The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more CTP is an example of

feedback inhibition of enzyme activity

Which of the following is the best evidence for the lock and key theory of enzyme action?

Enzymes are found in living organisms and speed up certain reactions

Compounds similar in structure to the substrate inhibit enzyme activity

Enzymes are found in living organisms and speed up certain reactions

Enzymes speed up reactions by definite amounts

Enzymes determine the direction of a reaction

The ability of Vibrio fischeri to convert chemical energy directly into radiant energy in bioluminescence is an example of __________ at work.

the third law of thermodynamics

the first law of thermodynamics

the third law of thermodynamics

Hydrogen and oxygen release enormous amounts of energy when they react. Yet, hydrogen and oxygen can be mixed together in a balloon and nothing will happen. Why?

There must be contaminating elements in the balloon that prohibit the reaction from occurring

Competitive inhibitors are blocking the reaction from occurring in the active site

There must be contaminating elements in the balloon that prohibit the reaction from occurring

The energy of activation to form the transition-state complex is too high to allow the reaction to occur without assistance

Denaturation of an enzyme refers to the

formation of the enzymes proper shape

improper arrangement of the enzyme in a metabolic pathway

loss of the enzymes proper shape

formation of the enzymes proper shape

formation of a new isozyme for that enzyme

About 7.3 kcal/mole are released when

glucose is converted to CO2 and H2O

ATP hydrolysis is coupled to sucrose synthesis

the terminal phosphate bond of ATP is broken by hydrolysis

If the free energy change (ΔG) in a reaction is a negative value, it indicates that the

reaction is in negative direction

reaction is in positive direction

If the Keq for an enzymatic reaction is greater than 1, the reaction

can not occur without the input of energy

An endergonic reaction is one that

requires energy in order to proceed

Amount of various immunoglobulin classes can be measured by

single diffusion in one dimension

double diffusion in one dimension

single diffusion in two dimensions

single diffusion in one dimension

double diffusion in two dimensions

25 + Mcqs in Reaction in Physics Page 1 McqOptions

1.	Anthranilate synthase, the first enzyme of tryptophan biosynthesis after the branch point shows feedback inhibition and repression due to
A.	L-tryptophan
B.	D-L-tryptophan hydantoin
C.	L-serine
D.	pyruvate
Answer» B. D-L-tryptophan hydantoin

Discussion

2.	The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more CTP is an example of
A.	enzyme induction
B.	enzyme repression
C.	feedback inhibition of enzyme activity
D.	none of these
Answer» D. none of these

Discussion

3.	Which of the following is the best evidence for the lock and key theory of enzyme action?
A.	Compounds similar in structure to the substrate inhibit enzyme activity
B.	Enzymes are found in living organisms and speed up certain reactions
C.	Enzymes speed up reactions by definite amounts
D.	Enzymes determine the direction of a reaction
Answer» B. Enzymes are found in living organisms and speed up certain reactions

Discussion

4.	To a living organism, which of the following has the greatest amount of available energy per molecule?
A.	ATP
B.	ADP
C.	AMP
D.	H2O
Answer» B. ADP

Discussion

5.	The ability of FADH to be oxidized is __________ than the ability of FAD to be oxidized.
A.	greater
B.	lesser
C.	approximately equal
D.	half
Answer» B. lesser

Discussion

6.	The affinity of an enzyme for its substrate, when the enzyme has a Km of 0.50 M will be __________ than the affinity of an enzyme for its substrate when the enzyme has a Km of 0.05 M.
A.	greater
B.	lesser
C.	approximately equal
D.	half
Answer» C. approximately equal

Discussion

7.	The ability of a competitive inhibitor to bind to an active site in an allosterically controlled enzyme is __________ than the ability of a non-competitive inhibitor to bind to an active site in the same allosterically controlled enzyme.
A.	greater
B.	lesser
C.	approximately equal
D.	half
Answer» B. lesser

Discussion

8.	The fact that β-oxidation of fatty acids, occurs in the mitochondria whereas fatty acid synthesis occurs in the cytoplasmic matrix, is an example of regulation of enzymatic activity by the __________ mechanism.
A.	compartmentation
B.	induction
C.	competitive inhibition
D.	repression
Answer» E.

Discussion

9.	The ability of Vibrio fischeri to convert chemical energy directly into radiant energy in bioluminescence is an example of __________ at work.
A.	Shelford's law of tolerance
B.	Leibig's law of the minimum
C.	the first law of thermodynamics
D.	the third law of thermodynamics
Answer» D. the third law of thermodynamics

Discussion

10.	Hydrogen and oxygen release enormous amounts of energy when they react. Yet, hydrogen and oxygen can be mixed together in a balloon and nothing will happen. Why?
A.	Competitive inhibitors are blocking the reaction from occurring in the active site
B.	There must be contaminating elements in the balloon that prohibit the reaction from occurring
C.	The energy of activation to form the transition-state complex is too high to allow the reaction to occur without assistance
D.	all of the above
Answer» B. There must be contaminating elements in the balloon that prohibit the reaction from occurring

Discussion

11.	Denaturation of an enzyme refers to the
A.	improper arrangement of the enzyme in a metabolic pathway
B.	loss of the enzymes proper shape
C.	formation of the enzymes proper shape
D.	formation of a new isozyme for that enzyme
Answer» C. formation of the enzymes proper shape

Discussion

12.	A substrate binds to its enzyme at a location called the __________ site.
A.	coenzyme
B.	substrate
C.	active
D.	polypeptide
Answer» D. polypeptide

Discussion

13.	About 7.3 kcal/mole are released when
A.	glucose is converted to CO2 and H2O
B.	NAD+ is reduced to NADH
C.	ATP hydrolysis is coupled to sucrose synthesis
D.	the terminal phosphate bond of ATP is broken by hydrolysis
Answer» B. NAD+ is reduced to NADH

Discussion

14.	In the reaction, C6H12O6+ 6O2 → 6CO2 + 6H2O + energy, which component is being oxidized?
A.	C6H12O6
B.	O2
C.	CO2
D.	H2O
Answer» B. O2

Discussion

15.	Adenosine triphosphate is a type of
A.	fatty acid
B.	amino acid
C.	nucleotide
D.	steroid
Answer» D. steroid

Discussion

16.	In the reaction, C6H12O6 + 6O2 → 6CO2 + 6H2O + energy, which component is being reduced?
A.	O2
B.	CO2
C.	H2O
D.	Energy
Answer» B. CO2

Discussion

17.	Reduction is the
A.	loss of proton
B.	gain of electron
C.	loss of electron
D.	gain of protons
Answer» C. loss of electron

Discussion

18.	If the free energy change (ΔG) in a reaction is a negative value, it indicates that the
A.	reaction releases energy
B.	reaction absorbs energy
C.	reaction is in negative direction
D.	reaction is in positive direction
Answer» B. reaction absorbs energy

Discussion

19.	Oxidation is the
A.	loss of proton
B.	gain of electron
C.	loss of electron
D.	gain of protons
Answer» D. gain of protons

Discussion

20.	If the Keq for an enzymatic reaction is greater than 1, the reaction
A.	will be endergonic
B.	can not occur without the input of energy
C.	both (a) and (b)
D.	none of these
Answer» E.

Discussion

21.	An endergonic reaction is one that
A.	requires energy in order to proceed
B.	releases energy for work
C.	gives off much heat
D.	looses energy
Answer» B. releases energy for work

Discussion

22.	An enzyme that is always produced, regardless of the presence of substrates or the end products, is called
A.	a constitutive enzyme
B.	an isoenzyme
C.	a repressible enzyme
D.	an allosteric enzyme
Answer» B. an isoenzyme

Discussion

23.	An exergonic reaction is one that
A.	requires energy to proceed
B.	releases energy for work
C.	gives off much heat
D.	looses energy
Answer» C. gives off much heat

Discussion

24.	Counter-immunoelectrophoresis is used for the detection of
A.	Meningococcal antigen
B.	Hepatitis B surface antigen
C.	Alpha-fetoprotein
D.	All of these
Answer» E.

Discussion

25.	Amount of various immunoglobulin classes can be measured by
A.	double diffusion in one dimension
B.	single diffusion in two dimensions
C.	single diffusion in one dimension
D.	double diffusion in two dimensions
Answer» C. single diffusion in one dimension

Discussion

Explore topic-wise MCQs in Physics.

Anthranilate synthase, the first enzyme of tryptophan biosynthesis after the branch point shows feedback inhibition and repression due to

The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more CTP is an example of

Which of the following is the best evidence for the lock and key theory of enzyme action?

To a living organism, which of the following has the greatest amount of available energy per molecule?

The ability of FADH to be oxidized is __________ than the ability of FAD to be oxidized.

The affinity of an enzyme for its substrate, when the enzyme has a Km of 0.50 M will be __________ than the affinity of an enzyme for its substrate when the enzyme has a Km of 0.05 M.

The ability of a competitive inhibitor to bind to an active site in an allosterically controlled enzyme is __________ than the ability of a non-competitive inhibitor to bind to an active site in the same allosterically controlled enzyme.

The fact that β-oxidation of fatty acids, occurs in the mitochondria whereas fatty acid synthesis occurs in the cytoplasmic matrix, is an example of regulation of enzymatic activity by the __________ mechanism.

The ability of Vibrio fischeri to convert chemical energy directly into radiant energy in bioluminescence is an example of __________ at work.

Hydrogen and oxygen release enormous amounts of energy when they react. Yet, hydrogen and oxygen can be mixed together in a balloon and nothing will happen. Why?

Denaturation of an enzyme refers to the

A substrate binds to its enzyme at a location called the __________ site.

About 7.3 kcal/mole are released when

In the reaction, C6H12O6+ 6O2 → 6CO2 + 6H2O + energy, which component is being oxidized?

Adenosine triphosphate is a type of

In the reaction, C6H12O6 + 6O2 → 6CO2 + 6H2O + energy, which component is being reduced?

Reduction is the

If the free energy change (ΔG) in a reaction is a negative value, it indicates that the

Oxidation is the

If the Keq for an enzymatic reaction is greater than 1, the reaction

An endergonic reaction is one that

An enzyme that is always produced, regardless of the presence of substrates or the end products, is called

An exergonic reaction is one that

Counter-immunoelectrophoresis is used for the detection of

Amount of various immunoglobulin classes can be measured by