This is a Biology exams assignment. So please answer it .

Here are the answers to your Biology exam assignment:

Cellular Respiration

1. Glycolysis: This is the initial breakdown of glucose into two molecules of pyruvate. It occurs in the cytoplasm and produces a net gain of 2 ATP and 2 NADH molecules.
2. Pyruvate Oxidation: Pyruvate enters the mitochondrial matrix and is converted into acetyl-CoA. This step releases one molecule of CO₂ and produces one NADH per pyruvate.
3. Citric Acid Cycle (Krebs Cycle): Acetyl-CoA enters this cycle in the mitochondrial matrix. For each acetyl-CoA, it produces 2 CO₂, 3 NADH, 1 FADH₂, and 1 ATP (or GTP).
4. Oxidative Phosphorylation: This is the main ATP-producing stage, occurring in the inner mitochondrial membrane. It involves the electron transport chain and chemiosmosis. Electrons from NADH and FADH₂ are passed along a series of protein complexes, releasing energy used to pump protons into the intermembrane space. This creates a proton gradient that drives ATP synthase to produce a large amount of ATP. Oxygen acts as the final electron acceptor, forming water.

Photosynthesis

1. Light-Dependent Reactions: These occur in the thylakoid membranes of chloroplasts. Light energy is absorbed by chlorophyll, exciting electrons. This energy is used to split water molecules (photolysis), releasing oxygen, protons, and electrons. The electrons move through an electron transport chain, generating ATP and NADPH.
2. Light-Independent Reactions (Calvin Cycle): These occur in the stroma of chloroplasts. ATP and NADPH from the light-dependent reactions are used to convert CO₂ into glucose. The cycle involves carbon fixation, reduction, and regeneration of the starting molecule, RuBP.

Enzymes

Enzymes are biological catalysts, typically proteins, that speed up biochemical reactions by lowering the activation energy. They bind to specific substrate molecules at their active site, forming an enzyme-substrate complex. This binding is often described by the lock-and-key model or the more accurate induced-fit model, where the enzyme's active site changes shape slightly to better fit the substrate. After the reaction, the products are released, and the enzyme is free to catalyze another reaction. Enzyme activity can be affected by temperature, pH, and the presence of inhibitors.