Tag: respiration

Quizzes (27) Questions (50)

Questions Related to respiration

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

Oxidation of glucose to CO$ _2$ and water occurs during

  1. Glycolysis

  2. Pentose phosphate pathway

  3. Krebs cycle

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

Pentose phosphate pathway is the only pathway in which glucose is completely oxidised to CO$ _2$ and H$ _2$O. It is also called HMP (hexose monophosphate shunt) as it is an alternate pathway to glycolysis. The primary substrate glucose is first phosphorylated to glucose-6-phosphate in presence of G6PD by consuming 1 ATP. A net gain of 35 ATP is achieved by oxidation of 1 molecule of glucose.

So the answer is 'Pentose phosphate pathway'.

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

Which of the following enzyme helps in conversion of 6-phosphogluconate to ribulose-5-phosphate?

  1. 6-phosphogluconate dehydrogenase

  2. Hexokinase

  3. Alpha-ketoglutarate

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

This conversion takes place during the oxidative phase of the pentose phosphate pathway.

Here, When 6-phosphogluconate converts to ribose 5-phosphate, the enzyme used is 6-phosphogluconate dehydrogenase. 
In this step an NADP⁺ converts to NADPH and CO₂ is released.
So, the correct option is '6-phosphogluconate dehydrogenase.'

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

 Erythrose 4-phosphate is used in synthesis of 

  1. Carbohydrates.

  2. Aromatic amino acid.

  3. NADH.

  4. Erythrose-4-phosphate.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Erythrose-4-phosphate is an intermediate produced in the pentose phosphate pathway.  It is involved in the biosynthesis of aromatic amino acids. All the carbons in phenylalanine and tyrosine are produced from erythrose-4-phosphate and phosphoenolpyruvate. Phenylalanine and tyrosine are aromatic amino acids. Thus the correct answer is option B.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry
Which of the following cellular metabolic processes can occur both in the presence or absence of ${O} _{2}$?

  1. Glycolysis

  2. Fermentation

  3. TCA cycle

  4. Electron transport coupled with chemiosmosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glycolysis is an oxidative process in which one molecule of glucose is partially oxidised into two molecules of pyruvate in a series of enzyme catalysed reactions. Glycolysis, the major pathway for glucose metabolism, occurs in the cytosol of cells. It is a unique pathway that occurs aerobically as well as anaerobically and does not involve molecular oxygen.

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

Which one of the following hormone never reaches to cytoplasm?

  1. Estrogen

  2. FSH

  3. Progesterone

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

FSH is a proteinaceous hormone. It does not enter its target cells, thus, it never reaches to cytoplasm. Instead, it binds to the receptor present on the cell membrane and activates a membrane bound enzyme that causes conversion of ATP to cAMP. This then alters the activities of enzyme in the cytoplasm.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry
Last ${e}^{-}$ acceptor during ETS is 
  1. ${O} _{2}$
  2. cyt $a$
  3. cyt ${a} _{2}$
  4. cyt ${a} _{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In electron transport chain, there are 7 electron acceptors, which are as follows $Co-Q\rightarrow Cyt\,\, b\rightarrow Cyt \,\,{c} _{1} \rightarrow Cyt \,\,c\rightarrow Cyt \,\,a\rightarrow Cyt \,\,{a} _{3}\rightarrow{O} _{2}$. Oxygen is the ultimate electron acceptor. These electron acceptors are present in a specific sequence along inner mitochondrial membrane.

Multiple choice biology respiration fermentation cell respiration living organisms and energy production

Aerobic respiration is more advantageous than anaerobic respiration because

  1. It requires oxygen

  2. It produces more energy

  3. It causes complete breakdown of respiratory substrate

  4. Aerobic respiration produces water.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The oxidative breakdown of respiratory substrates with the help of atmospheric oxygen is known as aerobic respiration. It involves a complete breakdown of substrates into carbon dioxide and water releasing energy. The energy released per mole of glucose is 686 Kcal or 2870 kJ. 

Oxidation of respiratory substrates in the absence of atmospheric oxygen is termed as anaerobic respiration. It involves an incomplete breakdown of respiratory substrates in which the end products such as ethanol or lactic acid are produced and carbon dioxide is released. The amount of energy released in this case is 247 kJ.
Since the energy released is more in aerobic respiration, it is more advantageous. Thus, the correct answer is option B.