Biology

Cellular Respiration and Enzymes

1,551 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 zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

Which of the following options contains the end products formed during anaerobic respiration in yeast?

  1. $H _2O, CO _2$ and energy
  2. $H _2S, C _6H _{12}O _6$ and energy
  3. $CO _2, C _2H _5OH$ and energy
  4. $H _2O$ and $CO _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Anaerobic respiration in yeast results in the production of ethyl alcohol, carbon dioxide and energy. $C _6H _{12}O _6 \xrightarrow[Complex]{Zymase} \underset{Ethyl \, alcohol}{2C _2H _5OH} + 2CO _2 + $

Multiple choice zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

Respiration oxidizes

  1. Glucose

  2. Carbon

  3. Nitrogen

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Respiration is a catabolic process that takes place in living organisms. In this glucose is broken down in presence of oxygen to generate ATP along with the production of water and evolution of carbon dioxide. It is an exergonic process. Thus the correct answer is option A.

Multiple choice zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

In respiration the energy is produced during the process of

  1. Glycolysis

  2. Krebs cycle

  3. Glycolysis and Krebs cycle

  4. Ornithine cycle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Glycolysis is the first step of respiration which converts the glucose molecules into two molecules of pyruvate along with the production of 8 ATP. The two pyruvate molecules produced by the glycolysis enters the Krebs cycle. Each molecule of pyruvate produces 15 ATP. So total 30 ATP is formed during the Krebs cycle. Total 38 ATP is formed during the aerobic respiration.

So, the correct answer is option C.

Multiple choice zoology respiratory system experiments on photosynthesis cellular respiration introduction to respiration

The common immediate source of energy in cellular activity is

  1. ADP

  2. ATP

  3. FAD

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

ATP is an Adenosine triphosphate (ribose sugar, adenine base, and three phosphate groups), where a high energy bond attaches the third phosphate group to the molecule. The highly unstable bonds break to release the inorganic phosphate to fulfill the energy required for the metabolism.

Hence, the correct answer is option B.

Multiple choice component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

Movement of ten electrons from mitochondrial NADH molecules produces water molecules

  1. 20

  2. 15

  3. 10

  4. 5
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the electron transport chain, each NADH molecule provides 2 electrons. 10 electrons (from 5 NADH molecules) react with oxygen to form 5 water molecules (since 4 electrons are required for 1 O2 to form 2 H2O).

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Respiration is a

  1. Anabolic process

  2. Deamination process

  3. Catabolic process

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The breaking of the C-C bonds of complex compounds through oxidation within the cells, leading to the release of a considerable amount of energy is called as respiration. As carbon-carbon covalent bonds are broken, it is a catabolic process. Respiration involves the synthesis of energy in form of ATP. The synthesis of ATP leads to the formation of several covalent linkages of phosphates. There is synthesis which are included in the anabolic processes.

Thus, the correct answer is option D.

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Catabolic and anabolic pathways are often coupled in cell because

  1. Both the paths have the same energy

  2. The free energy released from one pathway is used to drive other

  3. The intermediates of a catabolic pathway are used in the anabolic pathway

  4. Their enzymes are controlled by their activators and inhibitors.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Anabolic pathways are those that require energy to synthesize larger molecules. Catabolic pathways are those that generate energy by breaking down larger molecules. Both types of pathways are required for maintaining the cell's energy balance.
  • Catabolic and anabolic pathway are coupled because catabolic reactions furnish the energy required for anabolism. Catabolic reactions transfer energy from complex molecules to ATP. Anabolic reactions transfer energy from ATP to complex molecules.
  • Hence Catabolic and anabolic pathways are often coupled in the cell because the free energy released from one pathway is used to drive other.
  • So, the correct answer is 'the free energy released from one pathway is used to drive other'.
Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Which of the following activity is catabolic in nature?

  1. Cell repair

  2. Protoplasm synthesis

  3. Degradation of amino acid in liver

  4. Conversion of glucose to glycogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Catabolism involves the breakdown of a substance, often to release energy or during excretion for removal of waste. Degradation of amino acids in the liver is such an example where amino acids are broken down into inorganic substituents for recycling or removal.

Cell repair, protoplasm synthesis and conversion of glucose to glucose are all examples of anabolism which involves the synthesis of a product.
So the correct answer is 'Degradation of amino acids in the liver'.

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Glycogenolysis is a 

  1. Anabolic reaction

  2. Catabolic reaction

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The catabolic processes are the reactions in which the large complex molecules are broken down to produce smaller organic molecules. The polysaccharide which is a complex molecule is broken down to from many small monosaccharide molecules. For example, glycogen is broken down to produce glucose molecules and the process is known as glycogenolysis. 

Thus, the correct answer is option B. 

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Formation of nucleotide is a

  1. Anabolic reaction

  2. Catabolic reaction

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The nucleotides can be formed by two paths. When the nucleotide is formed due to the breaking of the bonds in the RNA and DNA, this process is an example of a catabolic process. When the nucleotides are formed from the nucleosides and nitrogenous bases, then this is an example of an anabolic process. 

Thus, the correct answer is option C. 

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Which of the following statement can be related to catabolism?

  1. It is an exergonic reaction

  2. It is an endergonic reaction

  3. It helps to break complex molecules to simple ones.

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The catabolic processes are the reactions in which the large complex molecules are broken down to form the smaller molecules. The process is an exergonic process in which the energy is released due to the breaking of the bonds of the larger complex molecules. The energy is released due to breaking of the bonds in the ATP molecule to produce ADP or AMP. 

Thus, the correct answer is option D. 

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Which is correct for catabolism of 18 C fatty acid

  1. Mitochondria, beta oxidation, 148 ATP molecules

  2. Mitochondria, beta oxidation, 140 ATP molecules

  3. Cytosol, beta oxidation, 146 ATP molecules

  4. Cytosol, beta oxidation, 140 ATP molecules
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For an 18-carbon fatty acid (stearic acid), beta-oxidation occurs in the mitochondria. The process yields 9 acetyl-CoA, 8 NADH, and 8 FADH2, resulting in a total of 148 ATP molecules after complete oxidation.

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Identify the anabolic process from the following.

  1. Photosynthesis

  2. Glycolysis

  3. Hydrolysis of starch

  4. Respiration
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Anabolism is the category of metabolism in which bio-molecules are synthesized. Whereas catabolism is breaking down of bio-molecules into simpler forms, mostly for the release of energy. 
  • During photosynthesis, carbohydrate is formed from carbon dioxide and water in presence of sunlight. 
  • Glycolysis is catabolic process releasing ATP.
  • Hydrolysis of starch is the break down of starch into simpler monosaccharides using water.
  • Respiration is the oxidative process releasing ATP. It has both catabolic as well as anabolic reactions involved hence it is rather considered as an amphibolic process.
So, the correct option is 'Photosynthesis'.
Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Which of the following is a catabolic reaction?

  1. Intercellular digestion

  2. Intracellular digestion

  3. Respiration

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The catabolic processes are the reactions in which the large complex molecules are broken down to form the smaller molecules. The process is an exergonic process in which the energy is released due to the breaking of the bonds of the larger complex molecules. Intracellular digestion refers to the breaking of the larger molecules. Intercellular digestion is the processes in which the molecules are broken down outside the cell and then absorbed. During internal respiration, there is the breakdown of the molecules to produce ATP. 

Thus, the correct answer is option D. 

Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

Choose the correct answers from the alternatives given .
All the chemical energy transformations that occur within a cell is called

  1. metabolism

  2. adaptation

  3. homeostasis

  4. photosynthesis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Metabolism is the set of life-sustaining chemical processes that enable organisms to transform the chemical energy stored in molecules into energy that can be used for cellular processes.
So, the correct option is 'metabolism'