Respiration in Plants: questions with answers

Glycolysis occurs in the cytoplasm and does not directly require oxygen, so it can operate in both shown conditions. One six-carbon glucose gives two three-carbon trioses, and the repeated later reactions produce two pyruvate molecules.

Glycolysis takes place in the cytoplasm and does not directly require oxygen. The six-carbon intermediate splits into two three-carbon trioses, both of which continue through the later reactions, yielding two pyruvate molecules.

Respiration occurs in all living plant cells, including non-green cells. Stomata, lenticels, internal air spaces, low demand and short diffusion distances allow each plant part to exchange gases mainly for itself, so no central respiratory organ is needed.

The overall equation summarises many enzyme-controlled reactions. Their staged energy release allows part of the energy to be trapped in ATP, whose breakdown supplies energy for cellular work.

The product depends on the organism or tissue: yeast forms ethanol and carbon dioxide, whereas oxygen-limited muscle and some bacteria form lactate. Both fermentations regenerate NAD+ and add no ATP beyond the net two ATP formed in glycolysis.

Glycolysis forms pyruvate in both aerobic and anaerobic conditions. Oxygen availability and cellular context influence the fate of pyruvate, while fermentation is incomplete and retains substantial energy in lactate or ethanol.

Pyruvate must be converted to acetyl CoA before the acetyl group enters the TCA cycle. Carbon dioxide release and reduced-carrier formation occur in matrix reactions without direct use of molecular oxygen, whose direct role is terminal in the ETS.

A TCA-cycle turn regenerates oxaloacetate and forms reduced carriers as major products. The complete per-acetyl ledger is 2 carbon dioxide, 3 NADH + H+, 1 FADH2 and 1 GTP/ATP equivalent, with oxaloacetate restored.

F0 is the integral inner-membrane proton channel, while the peripheral F1 headpiece on the matrix side contains the catalytic site. Protons flow down their electrochemical gradient through F0 from the intermembrane space to the matrix, coupling that passage to ATP formation at F1.

F0 is the integral inner-membrane proton channel and F1 is the peripheral catalytic headpiece. During ATP synthesis protons flow through F0 from intermembrane space to matrix; they are not sent in the reverse direction.

Fermentation only partially breaks down glucose and gives a net gain of two ATP through glycolytic substrate-level phosphorylation. Aerobic respiration completely degrades the substrate and adds extensive oxidative phosphorylation, so it can yield many more ATP under the theoretical assumptions.

Glycolysis and the succinyl-CoA step include substrate-level phosphorylation, so respiratory ATP is not all made by the ETS. Fermentation nets two ATP after incomplete breakdown, whereas aerobic respiration can produce many more under the theoretical assumptions.

Glycerol enters the respiratory pathway after conversion to PGAL, while fatty acids are degraded to acetyl CoA before entry. Thus neither product must return to glucose, and the two products do not share one entry point.

The first link is catabolic and the second is anabolic. Their connection through acetyl CoA shows that the respiratory pathway functions in both roles as a network, so it is amphibolic rather than only catabolic.

The first claim wrongly generalises carbohydrate's equal gas volumes: fat has RQ below one and protein about 0.9. The second claim ignores mixed substrate use, so an observed value need not identify one pure substrate with certainty.