Question

TCA cycle occurs in _____
(a) Mitochondria
(b) Chloroplast
(c) Cytoplasm
(d) Peroxisome

Answer 1

Dear Student,

● Answer - (a)

TCA cycle occurs in Mitochondria.

◆ Extra information -

● Krebs cycle -

• Krebs cycle is common pathway for oxidation of carbohydrates, proteins & fatty acids.
• It is also known as Citric Acid cycle or Tricarboxylic Acid (TCA) cycle.
• It takes place in mitochondria.

# Substrates entered -

• 1 acetyl CoA
• 2 oxaloacetate
• 6 NAD+
• 2 FAD+
• 2 ADP

# Products produced -

• 4 CO2
• 6 NADH
• 2 FADH2
• 2 ATP

● Significance of TCA cycle -

• At the end, pyruvate is broken down to CO2.
• It is essential step for production of ATP.
• It is final common oxidative pathway.
• It carries out the oxidation of fatty acids.
• It is major pathway in gluconeogenesis, fatty acid synthesis.
• It helps in amino acid metabolism. i.e. transamination and deamination.

Thanks dear. Hope this helps you...

Answer 2

TCA cycle occurs in Mitochondria.

Answer: Option (a)

Explanation:  

It is actually the ‘matrix of the mitochondria’ where ‘tricarboxylic acid’ cycle takes place. It is a common pathway for the assimilation of fats carbohydrates and proteins. This cycle is also known as the ‘Krebs cycle’ since it was discovered by Sir ‘Hans Krebs’.  

This cycle gives biproducts of water, carbon dioxide, ATP, NADH, FADH2. This products contain high energy ‘phosphate bonds’ which are hydrolysed to give energy. This process takes place only in case of ‘aerobic respiration’ where the ATP release is more.