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 enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis
The activity of the enzyme is increased in the presence of certain substances known as co-enzymes or activators.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Enzyme Catalysis:
The enzymes are also termed as biochemical catalysts and the phenomenon is known as biochemical catalysis. Enzymes are highly specific in nature.

Enzyme activators are molecules that bind to enzymes and increase their activity. They are the opposite of enzyme inhibitors. These molecules are often involved in the allosteric regulation of enzymes in the control of metabolism.

Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

The efficiency of an enzyme in catalysing a reaction is due to its capacity: 

  1. to form a strong enzyme substrate complex

  2. to decrease the bond energies in the substrate molecule

  3. to change the shape of the substrate molecule

  4. to lower the activation energy of the reaction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Enzymes are biological molecules (typically proteins) that significantly speed up the rate of virtually all of the chemical reactions that take place within cells by lowering the activation energy required for the reaction. It alters the pathway but doesn't take part in the reaction.

Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

Select the correct statement(s).

  1. Enzyme catalysed reactions are highly specific
  2. Enzyme catalysed reactions are highly susceptible to $pH$ and temperature

  3. Decomposition of glyceryl trinitrate is an example of autocatalysis

  4. The acid hydrolysis and alkaline hydrolysis of ester are reversible
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Multiple choice zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

Metabolism is 

  1. Release of energy

  2. Gain of energy

  3. Release or gain of energy

  4. Catabolism of a reaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Metabolism is sum total of all the reactions taking place in the cell. 
  • It involves the synthesis and degradation of various biomolecules for many functions like energy conservation, energy release, homeostasis etc.
  • Metabolism can Be divided into two categories: Catabolism - the breakdown of molecules to obtain energy and anabolism - the synthesis of all compounds needed by the body.
So, the correct option is 'Release or gain of energy'

Multiple choice zoology living and non living characteristics of life attributes of living organisms signs of life biology : an introduction living world and classification

Metabolism is 
A) Total of all the chemical reactions accuring in the body of organisms
B) Observed even outside the body in a test tube
C) Not observed in non-living objects

  1. A only

  2. C only

  3. AC only

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

A sequence of biochemical reactions occur in the living organisms is called Metabolism. it is the life-sustaining process occurs in the living organism and always takes place in the living organism. Metabolism can be demonstrated out side the living body. They do not occur in the non living body.

So, the correct option is 'ABC'.

Multiple choice biology protectors of biosphere structure of chloroplast plastids photosynthetic pigments

Quantasome is a unit related to

  1. Respiration

  2. Ascent of sap

  3. Growth

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

A) Quantasomes are not involved in respiration.
B) Xylem is involved in the ascent of sap. Quantasomes do not play a part in the ascent of sap.

C) Quantasomes are involved in photosynthesis. They do not directly contribute to growth.
D) Quantasomes are particles found on the inner thylakoid membrane of chloroplasts in which photosynthesis takes place.
So the correct answer is 'Photosynthesis'.

Multiple choice zoology ecosystems decomposition in ecosystem ecosystem productivity and decomposition producers, consumers and decomposers

Decomposition is a type of ______ 

  1. aerobic respiration

  2. anaerobic respiration

  3. exothermic reaction

  4. none of these.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When organic materials decompose in the presence of oxygen, the process is called “aerobic.” The aerobic process is most common in nature. For example, it takes place on ground surfaces such as the forest floor, where droppings from trees and animals are converted into relatively stable humus. There is no accompanying bad smell when there is adequate oxygen present. In aerobic decomposition, living organisms, which use oxygen, feed upon the organic matter. They use the nitrogen, phosphorus, some of the carbon, and other required nutrients. Much of the carbon serves as a source of energy for the organisms and is burned up and respired as carbon dioxide. Since carbon serves both as a source of energy and as an element in the cell protoplasm, much more carbon than nitrogen is needed. Generally, about two-thirds of carbon is respired as $C0 _2$, while the other third is combined with nitrogen in the living cells. However, if the excess of carbon over nitrogen (C: N ratio) inorganic materials being decomposed is too great, biological activity diminishes. Several cycles of organisms are then required to burn most of the carbon. 

So, the correct answer is A.

Multiple choice biology human health and disease drug, tobacco and alcohol consumption addiction and dependence community health and hygiene

Enzyme present in limited quantity in Asians for metabolism of alcohol is

  1. Alcohol dehydrogenase

  2. Succinate thiokinase

  3. Acetaldehyde dehydrogenase

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Acetaldehyde dehydrogenase is the enzyme which converts acetaldehyde into acetate. Acetaldehyde is produced from the metabolism of alcohol by the enzyme alcoholic dehydrogenase. Acetaldehyde is toxic and its accumulation can cause hangover so it needs to be metabolized. It is converted into acetate by aldehyde dehydrogenase. Acetate is then converted into carbon dioxide and water. About 50% people of northeast Asia have a dominant mutation in the gene encoding for enzyme aldehyde dehydrogenase resulteing in decreased activity of this enzyme. So, Asians have this enzyme in limited quantity.
So, the correct answer is 'Acetaldehyde dehydrogenase'.
Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

Which one of the following is one way cycle?

  1. Carbon cycle
  2. H$ _{2}$O cycle

  3. Free energy cycle
  4. O$ _{2}$ cycle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The transfer of energy in an ecosystem is always one way, from the sun to producers, from producers to herbivores, from herbivores to carnivores. The one way transfer of energy is in accordance with the laws of thermodynamics. 

Water, carbon and oxygen cycle in the ecosystem and are regularly exchanged between biotic and abiotic components.

Multiple choice zoology meaning of life energy flow and loss energy flow in a food chain energy flows

The energy flows from autotroph to the heterotrophs.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Energy flow always occurs from lower trophic level to a higher trophic level. According to Lindeman's law of trophic efficiency, about 10% of energy is transferred from one trophic level to the higher trophic level. Autotrophs are the producers. They occupy the first trophic level. Heterotrophs are consumers which occupy subsequent trophic levels as primary, secondary and tertiary consumers. Thus, energy transfer takes place from autotrophs to heterotrophs.
Hence, the statement given in the question is correct.
So, the correct answer is 'True'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

The elevated concentrations of cAMP indicates

  1. The activation of a cAMP-dependent protein kinase called protein Kinase A

  2. The activation of membrane receptors

  3. The splitting of ATP

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

Elevated levels of cAMP act as a second messenger that activates protein kinase A, which then phosphorylates target proteins to produce a cellular response.