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 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 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

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.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of these is a second messenger?

  1. ATP

  2. cAMP

  3. GTP

  4. ATP and AMP
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Second messengers are the intracellular molecules released by the cell in response to exposure to extracellular molecules i.e. first messengers. Extracellular molecules trigger the release of the secondary messengers.
  • The cAMP is a derivative of the ATP. It is used for many intracellular signalling pathways.
  • ATP is a nucleotide. It is created during respiration in the mitochondria of eukaryotic cells.
  • AMP is nucleoside triphosphate i.e. a type of nucleotide. AMP is used as a monomer of RNA, also used to generate ATP.
  • GMP is a nucleotide, that is used as a monomer of RNA
So, the correct answer is 'cAMP' 
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

A major regulatory mechanism for multistep reactions is

  1. Presence of inhibitors

  2. Availability of activators

  3. Feed-back mechanism

  4. All the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, a positive feedback system is childbirth. During labour, a hormone called oxytocin is released that intensifies and speeds up contractions and facilitates childbirth.
  • Hence A major regulatory mechanism for multistep reactions is the feedback mechanism.
  • So, the correct answer is 'Feed-back mechanism'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

In feedback inhibition, a metabolic pathway is switched off by the accumulation of end products.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Accumulation of end products triggers an inhibiting action as a feedback inhibition of the metabolic pathway causing its inhibition. as a result, the metabolic pathway is switched off or halted. For example, the absence of the suckling stimulus leads to inhibition of the milk secretion.

Hence, the correct answer is 'true'.

Multiple choice zoology soil pollution industrial chemicals and their harmful effects toxic wastes and their effects soil pollution-causes

Which of the following determines the action of protective enzyme?

  1. Catalyses the removal of hydrogen atoms from a particular molecule

  2. Phosphorylation of hexose

  3. Breaks the pesticide into less toxic chemicals

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

The question specifically asks about the action of a protective enzyme in the context of pesticides. These enzymes function by chemically breaking down the toxic pesticide molecules into less harmful compounds.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

The substance which is synthesized in Golgi body is?

  1. Protein

  2. Polysaccharides

  3. Fats

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

The substance which is synthesized in golgi body is polysaccharides. Golgi is a part of the cellular endomembrane system, the Golgi apparatus packages proteins into membrane-bound vesicles inside the cell before the vesicles are sent to their destination. The Golgi apparatus resides at the intersection of the secretory, lysosomal, and endocytic pathways. It is of particular importance in processing proteins for secretion, containing a set of glycosylation enzymes that attach various sugar monomers to proteins as the proteins move through the apparatus.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Carbohydrates, which are present in the cell membrane takes part in which of the following?

  1. Transport of substance.

  2. Cell recognition.

  3. Attachment to microfilament.

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

Carbohydrates which are present in the cell membrane take part in cell recognition. Cell recognition is defined as an active process giving rise to a specific response. 

Cell adhesion is a good example of cell recognition when it can be demonstrated that the adhesion is mediated by molecules having specific binding properties. Such cell adhesion molecules have now been identified in several cellular systems. Carbohydrates, or sugars, are sometimes found attached to proteins or lipids on the outside of a cell membrane. That is, they are only found on the extracellular side of a cell membrane. Together these carbohydrates form the glycocalyx. The glycocalyx of a cell has many functions. It can provide cushioning and protection for the plasma membrane, and it is also important in cell recognition. Based on the structure and types of carbohydrates in the glycocalyx, your body can recognize cells and determine if they should be there or not.