Biology

Cellular Respiration and Enzymes

1,721 Questions

Explore key concepts of cellular respiration, including glycolysis, the Krebs cycle, and the electron transport chain. These questions also cover ATP production, anaerobic respiration, and essential metabolic pathways. This topic forms a core part of the biology syllabus for many competitive examinations.

Glycolysis and metabolic pathwaysKrebs cycle processesElectron transport chainATP production countAnaerobic respiration products

Cellular Respiration and Enzymes Questions

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Oxidative phosphorylation occurs during 

  1. Transpiration

  2. Respiration

  3. Protein synthesis

  4. Nitrogen metabolism
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oxydative phosphorylation is the process of formation of ATP as a result of transfer of electrons from NADH or FADH$ _2$ to O$ _2$. This process which takes place in mitochondria and ATP is the major source of cellular respiration.

So, the correct option is 'Respiration'. 

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Which is end product of oxidative phosphorylation?

  1. ATP
  2. ATP + $H _2O$

  3. NADH

  4. Oxygen.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

the process produces the 2 pyruvate molecule with 2 water molecule, 2 ATP, 2 NADH molecules, and 2 hydrogen ions. At the end of electron transport, oxygen is the final electron acceptor, and it combines also with hydrogen ions to form H2O. The end product of oxidative phosphorylation would be ATP molecules, which carry energy.

So the correct option is 'ATP + H$ _2$O'.

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

FAD is electron acceptor during oxidation of 

  1. Ketoglutarate Succinyl CoA.

  2. Succinic acid Fumaric acid.

  3. Succinyl CoA Succinic acid.

  4. Fumaric acid Malic acid.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The hydrogen acceptor is FAD during the oxidation of Succinic acid Fumaric acid by succinate dehydrogenase.

So the correct option is 'Succinic acid Fumaric acid.'

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Mitochondrial electron transport chain is

  1. Cyclic phosphorylation.

  2. Oxidative phosphorylation.

  3. Noncyclic phosphorylation.

  4. Photooxidation.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The electron is transferred from NADH to oxygen in mitochondria con­sists of four multi-protein complexes is coupled to the synthesis of ATP from ADP and inorganic phosphate (Pi) which is called as oxidative phosphorylation. 

So the correct option is 'Oxidative phosphorylation.'

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Coenzyme $NAD^+$ and FAD are connected with respiratory reactions as they

  1. Are involved in each step of ATP synthesis.

  2. Function in Krebs cycle and terminal oxidative phosphorylation.

  3. Act as hydrogen carrier.

  4. Are reducing agents.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

NAD and FAD plays a major role in cellular respiration,  They carry the H+ and electrons to Electron Transport Chain to convert ADP + Pi ATP.

So the correct option is 'Act as a hydrogen carrier.'

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Glyceraldehyde phosphate is oxidised in glycolysis. The hydrogen atom and electron liberated cause

  1. Oxidation of NAD$^+$.
  2. Reduction of NAD$^+$.

  3. Change in oxaloacetic acid.

  4. Formation of methane.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glyceraldehyde-3-phosphate is oxidized by the coenzyme nicotinamide adenine dinucleotide (NAD). NAD+ is an oxidizing agent - it accepts electrons from other molecules and becomes reduced.

So the correct option is 'Reduction of NAD+'.

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Which of the following is a biological uncoupler of oxidative phosphorylation?

  1. Thermogenin.

  2. 2, 4-Dichlorophenoxyacetic acid.

  3. 2, 4-Dinitrophenol.

  4. Ethylene diaminotetra-acetic acid.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Brown adipose tissue is rich in mitochondria, containing an uncoupling protein (thermogenin) that uncouples oxidation and phosphorylation of adenosine diphosphate, reduces ATP production, and consequently enhances thermogenesis.

So the correct option is 'Thermogenin'.

Multiple choice bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

Identify the wrong statement.

  1. Proton motive force drives the uniport.
  2. Movement of NO$ _3$ ions in cotransport is against their own concentration gradient.

  3. Azides inhibit the process of respiration.

  4. ATPase serves as proton-translocating carrier protein.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Proton motive force drives ATP synthesis via ATP synthase, not uniport. The other statements describe known biological processes.

Multiple choice zoology our health harmful microorganism for humans microbes and diseases categories of diseases

Metabolic reactions tak place

  1. In vitro

  2. In vivo

  3. Both (a) an d(b)

  4. Only in unicellular organisms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Metabolic reactions are those chemical reactions through which a complex substance break into smaller molecules and produces the energy which helps in completing the life cycle of an organism. Metabolic reactions can take place in a living system e.g. digestion and respiration in the living organism. metabolic reactions also take place in an isolated cell-free system e.g. reactions take place in the test tube. Metabolic reactions take place in unicellular as well as multicellular organisms.

So, the correct answer is  ' Both (a) an d(b) '

Multiple choice zoology our health harmful microorganism for humans microbes and diseases categories of diseases

Which one of the following metabolic conversions requires oxygen > 

  1. Glucose to pyruvate
  2. Glucose to $CO _2$ and ethanol

  3. Glucose to lactate
  4. Glucose to $CO _2$ and $H _2O$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Aerobic respiration requires oxygen to fully oxidize glucose into carbon dioxide and water. The other options describe anaerobic processes or partial oxidation.

Multiple choice zoology respiration and energy transfer active transport and passive transport types of plant transport atp

Energy currency/coin of cell is

  1. ATP

  2. NAD

  3. ADP

  4. GDP
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ATP is adenosine triphosphate. It is formed of an adenine, a ribose and three phosphate radical attached to ribose. It is a storehouse of energy. It is found in all living cell. ATP is called energy currency as well as an energy carrier of the cell. ATP usually obtains energy during respiration. It provides energy for membrane transport, nerve conduction, cell movement, cell division etc. Breakage of one phosphate bond in the presence of ATP-ase and releases of 8.9Kcal per mole. Thus, the correct option is A.

Multiple choice zoology respiration in organisms active transport and passive transport types of plant transport atp

Which of the following is energy rich compound formed in cellular respiration?

  1. ADP

  2. Glucose

  3. Water

  4. ATP

  5. Oxygen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During cellular respiration, the energy formed in mitochondria is stored in the form of ATP which is also known as energy currency of the cell. It provides energy for all the life activities by its breakdown into ADP and Pi. ATP contains three phosphate group which has high energy bond. On the hydrolysis of ATP energy is released and ADP formed.

Multiple choice zoology respiration in organisms active transport and passive transport types of plant transport atp

Which one of the following is known as energy currency of cell?

  1. Adenosine diphosphate

  2. Adenosine triphosphate

  3. Pyruvate

  4. Glucose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Adenosine triphosphate (ATP) is known as the energy currency of the cell. There are three phosphate bonds which store a large amount of energy. When these bonds are broken down, the energy is released. The energy is used to carry out biochemical reactions in the cell.

Thus, the correct answer is option B. 

Multiple choice zoology respiration in organisms active transport and passive transport types of plant transport atp

The energy necessary for active transport across cytoplasmic membranes is believed to come from

  1. ATP

  2. Diffusion

  3. Osmosis

  4. Kinetic energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ATP is the energy currency of our body produced by the oxidation of food in the cell. ATP is utilized to proceed different metabolic process. Active transport is the movement of molecules across a cell membrane in the direction against the concentration gradient i.e., moving from an area of lower concentration to an area of higher concentration with the involvement of energy in the form of ATP.