Answer: Option C. -> ATP
:
C
ATP does not take part in e⁻ transfer. The energy released by the electron transport chain is stored in ATP. Whereas CoQ, Fe-S, $NA{D}^{+}$ are all part of the electron transport chain and take part in redox reactions.

Answer: Option D. -> All of the above
:
D
When carbohydrates are not available, other substrates are used for respiration. Proteins are broken down to amino acids and the amino acids can be used for respiration. Some amino acids enter the oxidative phosphorylation pathway as acetyl CoA, while others form pyruvate, oxaloacetate, alpha-ketoglutarate etc. Fatty acids basically enter citric acid cycle as acetyl CoA.

Answer: Option C. -> Pyruvate to acetyl CoA
:
C
$Pyruvate\stackrel{pyruvatedehydrogenase}{\to }AcetylCoA$
Pyruvate dehydrogenase is the enzyme that catalyzes the oxidation of pyruvate, by decarboxylating it to release carbon dioxide and it adds a coenzyme molecule to synthesize acetyl-CoA.

Answer: Option B. -> CO2
:
B
$C{O}_2$ is released during respiration and forms the product of respiration. Whereas in photosynthesis, the carbon dioxide molecule is fixed to form glucose. Therefore$C{O}_2$forms the substrate in photosynthesis.

Answer: Option A. -> All living cells
:
A
Glycolysis is a series of reactions that takes place in the cytoplasm of all prokaryotes and eukaryotes. The role of glycolysis is to produce energy (both directly and by supplying substrate for the citric acid cycle and oxidative phosphorylation) and to produce intermediates for biosynthetic pathway.

Answer: Option B. -> acetyl-CoA is converted to CO2 and H2O
:
B
Kreb’s cycle, also known as tricarboxylic acid cycle is a process in whichthe glycolytic product - pyruvic acid is converted to CO₂and H₂O. Pyruvic acid enters Kreb's cycle as acetyl-CoA. Kreb's cycle takes place in the mitochondria.

Answer: Option B. -> Pyruvate dehydrogenase
:
B
Pyruvic acid synthesized in glycolysis must enter inside the mitochondria, where oxidative decarboxylation occurs in the presence of NAD⁺and coenzyme-A. This results in the formation of acetyl CoA which can enter the Kreb's cycle. This reaction is catalyzed by pyruvate dehydrogenase.

Answer: Option D. -> Four
:
D
Six carbon dioxide molecules are released by complete oxidation of one glucose molecules. Two carbon dioxide molecules are released during oxidative decarboxylation reaction when the glycolytic products, that is two molecules of pyruvate areconverted into two molecules of acetyl CoA and channelled into the Kreb's cycle. And four carbondioxide molecules are released during theKreb’s cycle, during the breakdown of two molecules of isocitrate to alpha-ketoglutarate and the breakdown of alpha-ketoglutarates to succinyl CoA.

Answer: Option A. -> RNA nucleotide
:
A
ATP is an energy rich compound, which is anRNA nucleotide. A nucleotide is a moeity that consists of a ribose sugar, attached to a nitrogenous base, which is adenosine in case of ATP and a triphosphate group.
DNA nucleotide is very similar to a RNA nucleotide or a ribonucleotide, except it contains a deoxyribose sugar instead of the ribose sugar.

Answer: Option B. -> Less than one
:
B
Maize contains carbohydrate and groundnut seeds containfatty acids. R.Q of these substrates would be 1 for maize and less than 1 for groundnut. Therefore the total R.Q will be less than one.