Question

Match the number of carbon atoms given in List-I with that of the compounds given in List - II and select the correct combination from the following.

	List I		List II
A	4 C Compound	p	Acetyl-CoA
B	2 C Compound	q	Pyruvate
C	5 C Compound	r	Citric acid
D	3 C Compound	s	$\alpha$ -keto glutaric acid
		t	Malic acid

• A. A- q, B- t, C- r, D- p
• B. A- t, B- p, C- s, D- q
• C. A- r, B- p, C- s, D- q
• D. A- t, B- r, C- p, D- q

Answer 1

The correct option is B A- t, B- p, C- s, D- q

Malate plays an important role in biochemistry. In the $C_4$ carbon fixation process, malate is a source of $C{O}_2$ in the Calvin cycle. In the citric acid cycle malate is an intermediate formed by the addition of an OH group on the face of fumarate. It is a 4 C compound.
The initiating step of the citric acid cycle occurs when a four carbon compound condenses with acetyl-coA to form citric acid (6 C). The whole purpose of a 'turn' of the citric acid cycle is to produce two carbon dioxide molecules.
Glutaric acid is a 5C compound. It is naturally produced in the body during metabolism of some amino acids including lysine and tryptophan.
Glycolysis, the initial stage of glucose metabolism, takes place in the cytosol and does not involve molecular $O_2$. It produces a small amount of ATP and the three carbon compound pyruvate.