Tag: carbohydrate metabolism

Quizzes (9) Questions (178)

Questions Related to carbohydrate metabolism

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

Which one of the following produces more energy per glucose molecule?

  1. Alcoholic fermentation

  2. Glycolysis

  3. Pentose phosphate pathway

  4. Lactic acid fermentation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Glycolysis is a common pathway between the aerobic and anaerobic respiration. The net amount of ATP formed during glycolysis is two.

Alcoholic fermentation and lactic acid fermentation are both of pathways involved in the anaerobic respiration in which the pyruvic acid formed after glycolysis is converted into lactic acid or ethanol and carbon dioxide. The energy released during anaerobic respiration is much less as compared to the aerobic respiration.
So the correct option is, 'pentose phosphate pathway'

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

Which of the following pairs of structure and functions are correctly matched?
a. Tendril- Climbing
b. Penumatophore - Respiration
c. Stratospheric - checking UV or beta
d. Ozone shield - UV rays
Select the correct answer using the codes given.

  1. $2$ and $3$ only
  2. $1$ and $2$ only
  3. $1$ and $3$ only
  4. $1, 2$ and $3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

In hexose monophosphate shunt, the net formation of ATP molecules is

  1. 36

  2. 35

  3. 38

  4. 34
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hexose monophosphate shunt is an alternative pathway to glycolysis or the tricarboxylic acid cycle for glucose oxidation. It occurs in the cytoplasm and has two phases; the oxidative phase and the non-oxidative phase. 

This is the only process that generates reduced NADPH₂ which act as the reducing agent in the biosynthetic processes.
6 glucose molecules that enter hexose monophosphate shunt, produces 12 NADPH₂ and 6 carbon dioxide.
12 NADPH₂ molecules when undergo ETS forms  36 molecules of ATP.
So, the correct option is '36'

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


Which of the following is not a pathway that relates to generation of ATP?

  1. Pentose phosphate shunt

  2. Embden-Meyerhof pathway

  3. Oxidative-phosphorylation

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

  • Pentose phosphate shunt is the pathway that is used for the synthesis of a 5 carbon molecules such as ribose and deoxyriose which can be used for the synthesis of nucleotides, no ATP is produced during this reaction.
  • EMP pathway is the glycolysis process where 2 ATP are produced at the end of the reaction.
  • Oxidative phosporylation is the pathway that is used to reduce the NADH and FADH for the formation of ATP
  • And photosynthesis is the pathway in the plant that is used for the production of the carbohydrates that are used in the catabolic pathway for the synthesis of the ATP in cellular respiration.
  • Therefore the correct answer is option is 'Pentose phosphate shunt'.











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

Production of $NADPH _2$ is not linked with ATP generation in

  1. Photorespiration

  2. Light recation

  3. Hexose monophosphate pathway

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

Hexose monophosphate pathway (HMP) or pentose phosphate shunt is an alternate glucose metabolism that occurs in adipose tissues, liver, erythrocytes, testes, adrenal glands, mammary glads etc. This pathway is performed to generate the $NADPH _2$ to facilitate the cholesterol synthesis, steroid and lipid production and fatty acid synthesis. Thus signifying that HMP pathway readily takes place in tissues associated with lipogenesis like liver and adipose tissue. It is not linked with ATP generation. Also, the ribose sugars generated are used in DNA and RNA and many nucleotides like $ATP$, $FADH _2$ $CoA$ etc.

Photorespiration, light reaction and dark reaction are associated with phosphorylation.
Hence, the correct answer is 'Hexose monophosphate pathway'

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

Match the column I and II-

Column-I Column-II Site of pathway
(A) Fatty acid oxidation (p) Cytoplasm
(B) Pyruvate oxidation (q) Mitochondrial matrix
(C) Fatty acid synthesis (r) Mitochondrial inner membrane
(D) Pentose phosphate pathway (s) Glyoxysome
  1. A $\rightarrow$ p, B$\rightarrow$ q, C$\rightarrow$ r, D$\rightarrow$ s
  2. A $\rightarrow$ q, B$\rightarrow$ p, C$\rightarrow$ p, D$\rightarrow$ p
  3. A$\rightarrow$ p, B$\rightarrow$ r, C$\rightarrow$ q, D$\rightarrow$ s
  4. A $\rightarrow$ p, B$\rightarrow$ q, C$\rightarrow$ q, D$\rightarrow$ p
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B.


A. Fatty acid oxidation - (q) Mitochondrial matrix

B. Pyruvate oxidation  -(p) Cytoplasm
C. Fatty acid synthesis - (p) Cytoplasm
D. Pentose phosphate pathway-(p) Cytoplasm. 

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

Warburg-Dickens pathway is also known as

  1. P.P.P.

  2. TCA cycle.

  3. EMP pathway.

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

Pentose phosphate pathway (PPP) is variously called as Warburg-Dickens pathway and hexose monophosphate shunt. This metabolic pathway had been discovered through a number of experiments of Lippman, Warburg (1935) and Dickens (1938). 

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.