Tag: respiration

Quizzes (27) Questions (50)

Questions Related to respiration

Multiple choice biology respiration amphibolic pathway living organisms and energy production life processes in living organisms- part 1

Mitochondria is the site for

  1. Krebs cycle

  2. Calvin cycle

  3. Anaerobic respiration

  4. Trapping of sun light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The citric acid cycle is also known as the TCA cycle (tricarboxylic acid cycle) or the Krebs cycle. 
  • It is a series of chemical reactions used by all aerobic organisms to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins, into adenosine triphosphate (ATP) and carbon dioxide.
  •  In eukaryotic cells, the citric acid cycle occurs in the matrix of the mitochondrion.
  •  In prokaryotic cells, such as bacteria, which lack mitochondria, the citric acid cycle reaction sequence is performed in the cytosol. 
  • Hence, Mitochondria is the site for the Krebs cycle.
  • So, the correct answer is 'Krebs cycle'.
Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

HMP shunt was discovered by 

  1. Horecker and coworkers

  2. Warburg and Dickens

  3. Blackman

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

Hexose Monophosphate Pathway (HMP) is an alternative pathway of glucose break down found in animal tissues like liver, mammary glands, adrenal cortex, leucocytes and in many plant tissues. The pathway was first discovered by Warburg et. at. (1953) and Dickens (1938).

So, the correct answer is option B.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

The pentose monophosphate shunt is more advantageous than Krebs cycle as

  1. It yields more ATP

  2. Ribose sugar is released, which helps in nucleic acid formation

  3. It releases more oxygen

  4. It utilizes less oxygen
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pentose phosphate pathway is also known as HMP shunt. This pathway provides an alternative route for carbohydrate breakdown. HMP shunt produces some glycolytic intermediates like glyceraldehyde-3-phosphate and fructose-6-phosphate. These intermediates can directly involve in the glycolysis pathway and then in the Krebs cycle. The cycle provides ribose sugar which can be used for the synthesis of nucleic acids. This pathway is considered as advantageous since the ribose sugar is made available. 

Thus, the correct answer is option B. 

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Phosphogluconate shunt occurs in

  1. Mitochondria

  2. Chloroplasts

  3. Cytoplasm

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

The reactions of hexose monophosphate shunt occur exclusively in the cytoplasm and is an additional pathway of glucose metabolism which starts with glucose-6-phosphate. About 10-25% of glucose is metabolised by this pathway. In plants, it occurs both in cytosol and plastids. This pathway involves both oxidative and nonoxidative steps. The oxidative steps generate NADPH and ribose-5-phosphate and then non-oxidative steps convert ribose-5-phosphate back into glucose-6-phosphate which can be further utilized for NADPH generations by means of oxidative steps. 

Thus, the correct answer is option C. 

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

A respiratory cycle where mainly ${NADPH _2}$ are produced is 

  1. Calvin cycle

  2. Kreb's cycle

  3. EMP pathway

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

During Calvin cycle, $NADH _2$ are not produced. 
During Krebs cycle, 2 $NADH _2$, 1 $FADH _2$, 1GTP are produced. 
During EMP pathway 2 NADH, 2 ATP are produced. 
During HMP pathway, $NADPH _2$ are produced. So, in respiratory cycle  mainly $NADPH _2$ are produced is HMP pathway. Thus, option D is correct.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Pentose phosphate pathway is a mode of

  1. Amphibolic pathway

  2. Anabolic pathway

  3. Aerobic respiration

  4. Anaerobic respiration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pentose phosphate pathway is an alternative pathway to glycolysis which involves the oxidation of glucose-6-phosphate to 6-phosphogluconic acid which in turn gets converted into pentose phosphates. This pathway involve the direct oxidation of glucose-6-phosphate without entering glycolysis and hence is termed as direct oxidation. 

Thus, the correct answer is option C. 

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Which of the following is generated in the oxidative phase of pentose phosphate pathway?

  1. NADPH

  2. FADH

  3. GTP

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

The Pentose Phosphate Pathway is an alternative pathway to glycolysis and TCA cycle. It occurs in both prokaryotes and eukaryotes in their cytoplasm

Glucose is broken down by a series of pathways.
The pathway has 2 phases- Oxidative and Non-oxidative.
In the oxidative stage, there are 2 steps where NADP⁺ gets converted to NADPH.
1. Glucose 6-phosphate converts to 6-phosphogluconolactone
2. 6-phosphogluconate converts to Ribulose 5- phosphate
So, the correct option is 'NADPH'

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Pentose phosphate pathway takes place only in the

  1. Cytoplasm

  2. Mitchondria

  3. Peroxisome

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

The pentose phosphate pathway is a metabolic pathway which is carried out in most of the organisms. This pathway occurs parallel to glycolysis. This pathway produces pentoses from glucose 6-phosphate. The pathway takes place in the cytoplasm in most of the organisms. In the case of plants, there are certain reactions which occur in the plastids.

Thus, the correct answer is option A. 

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Pentose phosphate pathway takes place only in the

  1. Cytoplasm.

  2. Mitochondria.

  3. Peroxisome.

  4. Chloroplast.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The pentose phosphate pathway is a metabolic pathway which is carried out in most of the organisms. This pathway occurs parallel to glycolysis. This pathway produces pentoses from Glucose 6-phosphate. The pathway takes place in the cytoplasm in most of the organisms. In the case of plants, there are certain reactions which occur in the plastids.
Thus, the correct answer is option A.