Question

The Embden-Meyerhof, the pentose phosphate, and the Entner-Doudoroff pathways are all examples of . . .  

	A.	glycolysis pathways that yield ATP and pyruvate.
	B.	alternative names for the TCA cycle.
	C.	different types of fermentation reactions.
	D.	electron transport systems.
	E.	different pathways for fixing carbon.

Answer 1

Option (A) is correct answer.
• Glycolysis pathways that yield ATP and pyruvate.

Embden-Meyerhof pathway :-
• Glycolysis is also named Embden–Meyerhof–Parnas pathway on names of scientists who discovered it.
• This is first step in cellular respiration. It occurs at cytoplasm in presence of various enzymes.
• One glucose is converted to two pyruvate molecules and net 2ATP and 2 NADH are produced by this process.

Pentose phosphate pathway :-
• This is a parallel pathway to glycolysis and ribose 5-phosphate is produced by this process.
• Ribose 5-phosphate can be used a precursor to nucleotide synthesis or it can be enter in glycolysis by converting into fructose 6 - phosphate and gives same result as glycolysis.

Entner–Doudoroff pathway :-
• This is a alternative of glycolysis which is found in some bacteria.
• Products of this pathway are also similar to glycolysis but intermediates are different from glycolysis.

Other options :-
• Tricarboxylic acid cycle (TCA cycle) - other name of this cycle is krebs cycle. It occurs in mitochondria and NADH, FADH2 and carbon dioxide are produced by this process.
• Fermentation - this is type of cellular respiration pathway in absence of oxygen. Two types - alcoholic and lactic acid fermentation.
• Electron transport system - This is series of electron carriers in inner mitochondrial membrane which converts FADH2 and NADH to ATP.
• Calvin cycle is carbon fixation cycle. This is part of photosynthesis in plants. Carbon dioxide is fixed by rubisco enzyme in this cycle