What is the role of FADH$${_2}$$ and NADH in cellular respiration?

Carry electrons to the cytochrome membrane proteins

Catalyze the breakdown of glucose to three carbon sugars

Catalyzes the addition of a phosphate group to ADP

Act as a final electron acceptor in the electron transport chain

Transport hydrogen ions across the inner mitochondrial membrane

MCQ Questions for Class 11 Medical Biology Respiration In Plants Quiz 8

In alcohol fermentation,

0%
Triose phosphate is the electron donor, while acetaldehyde is the electron acceptor.
0%
There is no electron donor.
0%
Oxygen is the electron acceptor.
0%
None of the above.

How many carbon dioxide is produced by reduction of pyruvate by Kreb's cycle?

0%
2
0%
3
0%
4
0%
1

RQ of which diet is less than unit?

0%
Carbohydrate
0%
Fats
0%
Organic acid
0%
Sugar

Which enzyme breaks down the fructose 1, 6-diphosphate?

0%
Hexokinase
0%
Phosphatase
0%
Aldolase
0%
None of the above

Acceptor of acetyl Co-A in the Krebs cycle is

0%
Malic acid.
0%
Fumaric acid.
0%
$\alpha$ - ketoglutaric acid.
0%
Oxaloacetic acid.

Pyruvic acid before combining with oxaloacetic acid of Krebs cycle, becomes

0%
Citric acid.
0%
Acetoacetic acid.
0%
Cis-aconitic acid.
0%
Acetyl Co-A.

Which of the following is the site of Krebs cycle?

0%
Chloroplast
0%
Golgi body
0%
Mitochondria
0%
Endoplasmic reticulum

Explanation

Krebs cycle occurs in the mitochondrial matrix and oxidizes acetyl-CoA into carbon dioxide with the simultaneous production of reduction coenzymes, like

N A D H_{2}

$NADH_2$ and

F A D H_{2}

$FADH_2$ .

Glucose is oxidised to ethyl alcohol during the process of

0%
Respiration.
0%
Aerobic respiration.
0%
Anaerobic respiration.
0%
Photosynthesis.

The rubber we obtain from rubber plants is

0%
Plant food
0%
Plant tissue
0%
Plant waste
0%
Plant fruit

The membrane-bound enzyme that is involved in Krebs cycle occurring in mitochondria is

0%
Fumarase.
0%
Cis - aconitase.
0%
Malate dehydrogenase.
0%
Citrate synthase.

Krebs cycle begins with

0%
Citric acid.
0%
Pyruvic acid.
0%
Malic acid.
0%
Hydrochloric acid.

All enzymes of the TCA cycle are located in the mitochondrial matrix except one, which is located in inner mitochondrial membrane in eukaryotes and in cytosol in prokaryotes. This enzyme is

0%
Succinate dehydrogenase.
0%
Lactate dehydrogenase.
0%
Isocitrate dehydrogenase.
0%
Malate dehydrogenase.

Explanation

Krebs cycle (TCA cycle) occurs in mitochondrial matrix and produces reduced coenzymes, like

N A D H_{2}

$NADH_2$ and

F A D H_{2}

$FADH_2$ .

The succinate dehydrogenase enzyme is bound to inner mitochondrial membrane and catalyzes the conversion of succinate to fumarate with the simultaneous reduction of FAD to

F A D H_{2}

$FADH_2$ . In prokaryotes also this enzyme is bound to plasma membrane. This enzyme is an important example of membrane bound enzyme.

The first product of Krebs cycle is

0%
Pyruvic acid
0%
Citric acid
0%
Malic acid
0%
Lactic acid

The energy releasing process in which the substrate is oxidised without an external electron acceptor is called as

0%
Aerobic respiration.
0%
Glycolysis.
0%
Fermentation.
0%
Photorespiration.

In respiration, pyruvic acid is

0%
Broken down into two carbon fragments and carbon dioxide.
0%
Formed only when oxygen is available.
0%
One of the products of Krebs cycle.
0%
A result of protein breakdown.

R.Q. is measured by

0%
Mercury manometer.
0%
Respirometer.
0%
Auxanometer.
0%
Calorimeter.

Acetylation of pyruvate takes place in the

0%
Peri-mitochondrial space.
0%
Mitochondrial matrix.
0%
Cristae.
0%
F $_1$ particles.

Decarboxylation is involved in the

0%
Electron transport system
0%
Glycolysis
0%
Krebs cycle
0%
Lactic acid fermentation

Which of the following is the connecting link between glycolysis and Krebs cycle?

0%
Acetyl CoA
0%
Oxalo succinic acid
0%
Pyruvic acid
0%
Citric acid

Explanation

$\textbf{Correct answer: A}$

$\textbf{Option (A):}$

$\bullet$ Glycolysis is the first part of cellular respiration which occurs in both aerobic and anaerobic respiration.

$\bullet$ The end product of glycolysis is pyruvate. Pyruvate is oxidized to produce acetyl CoA.

$\bullet$ This acetyl CoA enters the Krebs cycle which occurs in the mitochondrial membrane. So, acetyl CoA acts as the connecting link between the two processes.

$\textbf{Option (B):}$

$\bullet$ Oxaloacetic acid is a residue which is part of the Krebs cycle and it is not the connecting link.

$\textbf{Option (C):}$

$\bullet$ Pyruvic acid is the end product of glycolysis and it needs to be oxidized.

$\bullet$ Pyruvate is not able to enter the Krebs cycle directly.

$\textbf{Option (D):}$

$\bullet$ Citrate is one of the intermediates in the Krebs cycle.

Hence, the correct answer is option (A).

Anaerobic respiration, that occurs after glycolysis is also called as

0%
Fermentation.
0%
Fragmentation.
0%
Restoration.
0%
Multiplication.

Enzyme encolase catalyses the conversion of

2

$2$ PGA to phosphoenol pyruvic acid in presence of ____________, which is the cofactor.

0%
$Mn^{++}$
0%
$Fe^{++}$
0%
$Mg^{++}$
0%
$Zn^{++}$

During anaerobic respiration the conversion of pyruvate into acetaldehyde, along with co-enzyme TPP, the cofactor required is

0%
$Mg^{++}$ .
0%
$Mn^{++}$ .
0%
$Fe^{++}$ .
0%
$Zn^{++}$ .

Synthesis of one glucose molecule requires ___________ reduced NADP molecules.

0%
$6$
0%
$12$
0%
$18$
0%
$24$

Explanation

For every three molecules of

C O_{2}

$CO_2$ that enters the Calvin cycle, one molecule of the three carbon glyceraldehyde 3-phosphate (G3P) is produced. Two molecules of G-3-P are needed to produce one molecule of glucose. Therefore, the Calvin cycle needs to make a total of 6 turns to produce two molecules of G-3-P. One turn of the Calvin cycle requires 3 molecules of ATP and 2 molecules of NADPH so for 6 turns-

3 ATP x 6 = 18 ATPs

2 NADPH x 6 = 12 NADPHs

Pyruvate kinase enzyme catalyses

0%
First irreversible step of glycolysis
0%
Second irreversible step of glycolysis
0%
Third irreversible step of glycolysis
0%
Fourth irreversible step of glycolysis

Citric acid cycle is the alternate name of which of the following?

0%
HMP shunt
0%
Glycolysis
0%
TCA cycle
0%
Calvin cycle

Identify the correct pair of statements.
I) Niacin containing coenzyme facilitates the oxidation of malate in the matrix of mitochondria.
II) Heme is the prosthetic group for the enzyme which catalyses the carboxylation of RuBP in the stroma of chloroplast.
III) The electron carrier between cytochrome C reductase and cytochrome C oxidase is attached to the inner surface of inner membrane of mitochondria.
IV) Water splitting reaction in the lumen of thylakoid requires chlorine.

0%
I, II
0%
I, IV
0%
II, III
0%
III, IV

Who contributed to the research process on fermentation?

0%
Johannes Miller
0%
Matthias Jakob
0%
Robert Brown
0%
Schwann Theodor

Which of the following substances yield less than

4 K c a l / m o l

$4 {Kcal}/{mol}$ , when its phosphate bond is hydrolysed?

0%
Creatine phosphate
0%
ADP
0%
Glucose-6-phosphate
0%
ATP

Explanation

$\textbf{Correct Option C}$

$\textbf{Solution}$

$\bullet$ $\textbf{Option A}$ Option A. When the phosphate bond of creatine phosphate is hydrolyzed is a yield of high free energy. The reason for this high free energy is the difference between the free energies of the reactants and the products.

$\bullet$ $\textbf{Option B}$ ADP is hydrolyzed the free energy released during the reaction is around a range of 7.3 Kcal/mol.

$\bullet$ $\textbf{Option C}$ During the hydrolysis of glucose 6 phosphate the yield of free energy have a negative value which is around -3.3 Kcal/mol.

$\bullet$ $\textbf{Option D}$ Reaction of hydrolysis of the phosphate found in ATP the range of the free energy released is 7.3 Kcal/mol.

So, the correct option is C.

Which one is product of aerobic respiration?

0%
Malic acid
0%
Ethyl alcohol
0%
Lactic acid
0%
Pyruvic acid

Which one is wrong about fermentation?

0%
It is anaerobic.
0%
It requires glucose.
0%
It produces energy.
0%
It requires oxygen.
0%
It produces ethanol.

Explanation

Fermentation is anaerobic respiration that does not require oxygen for the breakdown and transformation of organic nutrients.
Fermentation is controlled by enzymes.
The common product of fermentation are ethanol, CO $_2$ , and lactic acid.
Some amount of energy is also produced in the process of fermentation.

Fermentation — Definition & Role in Cellular Respiration - Expii

So, the correct answer is option D.

The first stable compound formed in Krebs cycle is

0%
Acetyl Co-A.
0%
Citric acid.
0%
Oxaloacetic acid.
0%
Fumaric acid.

Which element is required by the process designated as (III)?

0%
Chlorine
0%
Nitrogen
0%
Oxygen
0%
Potassium
0%
Sodium

Explanation

Electron transport chain (III) includes downhill flow of electrons from NADH and

F A D H_{2}

$FADH_2$ to final electron acceptor (Oxygen) through a chain of membrane-bound carriers to facilitate the uphill transport of protons across a proton-impermeable membrane. Since inner mitochondrial membrane is impermeable to protons; protons can reenter the matrix only through

F_{o}

$F_o$ particles of ATP synthase. The proton-motive force that drives protons back into the matrix provides the energy for ATP synthesis. Correct answer is C.

Which of the following statement is not associated with the Kreb's cycle?

0%
The Krebs cycle occurs in the matrix of the mitochondrion.
0%
The Krebs cycle is linked to glycolysis by pyruvate.
0%
The Krebs cycle is the single greatest direct source of ATP in the cell.
0%
Citrate is an intermediate in the Krebs cycle.
0%
The Krebs cycle produces nucleotides such as NADH and $FADH_2$ .

The formation of NAD via anaerobic pathway takes place by

0%
Glycolysis.
0%
Fermentation.
0%
Krebs cycle.
0%
Electron transport chain.
0%
Photosynthesis.

Product of fermentaion is
I. Oxygen
II. Carbon dioxide
III. Lactate
IV. Ethanol

0%
I only
0%
II only
0%
II and IV only
0%
III and IV only
0%
II, III and IV only

Carbon dioxide is used in the production of three carbon sugar by which of the following method?

0%
Photosystem- I
0%
Photosystem- II
0%
Electron transport chain
0%
Calvin cycle
0%
Citric acid cycle

Explanation

Carbon dioxide is used in the production of three carbon sugar 3-phosphoglycerate, called as PGA. This PGA enters the Calvin cycle.

In the Calvin cycle, carbon atoms from CO

_{2}

${_2}$ are fixed and used to build three carbon sugars. This process is fueled by, and dependent on ATP and NADPH from the light reactions. When two of the three carbon sugars produced by the Calvin cycle come together, they can combine to form a glucose molecule. Glucose may be broken down to fuel cellular respiration or stored as starch for later use. The carbon atoms from glucose can also be used to build other types of biological molecules.

Which of the following process occurs in the mitochondrial matrix?

0%
Glycolysis
0%
Fermentation
0%
Krebs cycle
0%
Electron transport chain
0%
Photosynthesis

What is the role of FADH

_{2}

${_2}$ and NADH in cellular respiration?

0%
Catalyze the breakdown of glucose to three carbon sugars
0%
Carry electrons to the cytochrome membrane proteins
0%
Catalyzes the addition of a phosphate group to ADP
0%
Act as a final electron acceptor in the electron transport chain
0%
Transport hydrogen ions across the inner mitochondrial membrane

In the atmosphere, carbon dioxide is directly released by

0%
Animal consumption of producers.
0%
Photosynthesis.
0%
Chemosynthesis.
0%
Bacterial decay.
0%
None of the above.

Select the correct stages of aerobic respiration.
I. Produces most of the ATP
II. Produces carbon dioxide

(C O_{2})

$\left(C{O}_{2}\right)$
III. Uses oxygen

(O_{2})

$\left({O}_{2}\right)$

0%
I = chemiosmosis; II = electron transport chain; III = citric acid cycle
0%
I = chemiosmosis; II = citric acid cycle; III = electron transport chain
0%
I = citric acid cycle; II = chemiosmosis; III = electron transport chain
0%
I = electron transport chain; II = chemiosmosis; III = citric acid cycle
0%
I = electron transport chain; II = citric acid cycle; III = chemiosmosis

Explanation

Chemiosmosis (I) includes the use of proton motive force to drive transport of protons down the concentration gradient and simultaneous ADP phosphorylation. It makes total 32 to 34 ATPs. Citric acid cycle (II) is the second phase of cellular respiration in which acetyl coA is enzymatically oxidized to carbon dioxide and the released energy is stored in NADH and FADH2. Electron transport chain (III) includes the transfer of electrons from NADH and

F A D H_{2}

$FADH_2$ through a series of protein complexes to final electron acceptor oxygen. Thus, the correct answer is B.

In the absence of oxygen, plants will break down sugars into carbon dioxide and alcohols or acids. This pathway likely arose

0%
To get the most out phosphorylation per molecule of pyruvate without the ability to utilize respiration.
0%
As an alternative process to compete with respiration.
0%
To regenerate depleted NAD $^+$ .
0%
Because of human cultivation.

Explanation

In absence of O

_{2}

$_2$ respiration takes place anaerobically, for release of ATP as a result of this process NADH is converted to NAD

^{+}

$^+$

So, the correct answer is 'To regenerate depleted NAD

^{+}

$^+$ '

Which of the biochemical pathways produce ATP, NADH, and FADH

_{2}

$_{2}$ from pyruvate?

0%
Krebs cycle
0%
Electron transport chain
0%
Fermentation
0%
Glycolysis
0%
Calvin cycle

Explanation

Glycolysis is the first step of cellular respiration that breaks down glucose into two molecules of pyruvic acid. The pyruvic acid enters Kreb cycle in form of acetyl-CoA where it is oxidatively decarboxylated with the production of NADH and

F A D H_{2}

$FADH_2$ . Substrate level phosphorylation also produces 2 ATPs during Kreb cycle. Fermentation of pyruvic acid does not produce

F A D H_{2}

$FADH_2$ . Calvin cycle refers to dark reactions of photosynthesis. Electron transport chain produces NAD, FAD by oxidation of NADH and

F A D H_{2}

$FADH_2$ . Thus, the correct answer is A.

Several different molecules carry high-energy electrons to the electron transport chain to generate ATP molecules.
Which of these high-energy electron carriers is only generated in the Krebs cycle?

0%
NADPH
0%
FADH $_2$
0%
NADH
0%
ATP

Explanation

The high energy electron carriers that are generated only during Kreb's cylce is FADH

_{2}

$_2$ , it also includes NADH and ATP, which are also generated during photosynthesis

So, the correct answer is 'FADH

_{2}

$_2$ '

In the anaerobic process of glycolysis, energy is released from ATP is used to

0%
phosphorylate glucose
0%
Phosphorylate ADP.
0%
Move glucose into the Calvin cycle.
0%
Carry ATP to the electron transport chain.

Substrate Level Phosphorylation results in the production of ATP molecules.
During which of the following processes does substrate level phosphorylation occur?
1. Glycolysis
II. Krebs Cycle
III. Electron Transport Chain

0%
I only
0%
II only
0%
III only
0%
I and II only
0%
II and III only

Fermentation is a type of anaerobic respiration that occurs in yeast and bacteria. What is the function of fermentation?
I. Regenerate

N A D^{+}

$NAD^+$ from NADH
II. Produce oxygen as a waste product
Ill. Produce ATP

0%
I only
0%
II only
0%
III only
0%
I and II only
0%
I and III only

Which is the correct order for the processes involved in aerobic cellular respiration?

0%
Krebs cycle, glycolysis, electron transport chain.
0%
Glycolysis, Krebs cycle, electron transport chain.
0%
Glycolysis, fermentation, electron transport chain.
0%
Fermentation, Krebs cycle, electron transport chain.
0%
Glycolysis, electron transport chain, fermentation.

As a pathway, glycolysis is an example of a coupled reaction.
It is strictly an anaerobic reaction, in which the energy investment phase is dependent upon

0%
The hydrolysis of ATP to ADP and $P_i$ .
0%
The presence of glucose as a substrate.
0%
The presence of oxygen and its conversion to carbon dioxide.
0%
The synthesis of pyruvate.

Pyruvate undergoes oxidative decarboxylation to produce

0%
2-PGA.
0%
$\alpha$ -Ketone.
0%
Succinyl Co-A.
0%
Acetyl Co-A.

NADH is a high energy electron carrier molecule. During which reactions is NADH produced?
I. Glycolysis
II. Krebs cycle
III. Conversion of pyruvate to Acetyl-CoA

0%
I only
0%
II only
0%
I and II only
0%
l and Ill only
0%
I, II, and III

CBSE Questions for Class 11 Medical Biology Respiration In Plants Quiz 8 - MCQExams.com

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Practice Class 11 Medical Biology Quiz Questions and Answers

CBSE Questions for Class 11 Medical Biology Respiration In Plants Quiz 8 - MCQExams.com

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Practice Class 11 Medical Biology Quiz Questions and Answers

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