The electron transport chain produces the majority of ATP through oxidative phosphorylation. Glycolysis and the Krebs cycle contribute far less ATP compared to this process.

Mitochondria are known as the powerhouse of the cell because they generate ATP through oxidative phosphorylation. Other organelles perform different cellular functions unrelated to ATP synthesis.

Chlorophyll is the main pigment that absorbs light energy for photosynthesis. Although other pigments can absorb light as accessory pigments, chlorophyll is crucial for energy capture.

Fermentation allows cells to produce ATP in the absence of oxygen by regenerating NAD+ for glycolysis. In contrast, aerobic respiration and the citric acid cycle rely on oxygen.

Enzymes speed up metabolic reactions by lowering the activation energy required, making the reactions proceed faster. They do not alter the equilibrium or provide energy directly.

Glycolysis converts one molecule of glucose into two molecules of pyruvate through a series of enzyme-catalyzed steps. Pyruvate is then used in subsequent metabolic pathways depending on oxygen availability.

The Krebs cycle takes place in the mitochondrial matrix where the necessary enzymes and substrates are located. It does not occur in the cytosol or within chloroplasts.

Cytochrome c is a mobile electron carrier that shuttles electrons between complexes in the electron transport chain. The other options are large, integral membrane proteins that do not move freely.

The Calvin cycle is responsible for incorporating CO2 into organic molecules during photosynthesis. The light-dependent reactions generate the energy-rich molecules needed for this process.

Allosteric regulation involves the binding of molecules to sites other than the enzyme's active site, thereby changing its conformation and activity. This mechanism provides fine control over metabolic pathways.

Lactic acid fermentation converts pyruvate into lactate, which regenerates NAD+ required for glycolysis to continue. Alcoholic fermentation, on the other hand, produces ethanol and CO2.

ATP synthase uses the energy from the proton gradient established by the electron transport chain to generate ATP. It does not transport electrons or directly oxidize NADH.

Carotenoids serve as accessory pigments by broadening the spectrum of light absorption and protecting chlorophyll from photodamage. They play a crucial photoprotective role in photosynthesis.

NADH, produced during glycolysis, carries electrons to the electron transport chain where they are used for ATP production. FADH2 is generated later during the Krebs cycle.

High levels of ATP act as a negative feedback inhibitor on phosphofructokinase, slowing down glycolysis when energy is abundant. This regulation helps maintain energy balance in the cell.

A lower substrate affinity is reflected by an increased Km, meaning that a higher concentration of substrate is needed to achieve half-maximal enzyme activity. This results in a slower glycolytic rate under normal conditions.

Inhibiting Complex III prevents the forward flow of electrons, causing an accumulation of reduced electron carriers such as cytochrome c. This disruption impairs the overall function of the electron transport chain.

Fermentation relies solely on glycolysis for ATP production, omitting the energy-rich steps of oxidative phosphorylation present in aerobic respiration. This results in a significantly lower ATP yield per glucose molecule.

The D1 protein is essential for the proper function of photosystem II, specifically in splitting water molecules. A mutation in this protein leads to reduced water splitting and diminished electron flow, impairing the light-dependent reactions.

NAD+ is a necessary cofactor for the glyceraldehyde-3-phosphate dehydrogenase step in glycolysis. In anaerobic conditions, regenerating NAD+ via fermentation is crucial to keep glycolysis running for ATP production.