Cellular Energetics

Flashcards for exam review.

Enzymes

Biological catalysts that speed up chemical reactions by lowering the activation energy required.

ATP (Adenosine Triphosphate)

The main energy carrier in cells; stores energy in its phosphate bonds.

Cellular Respiration

The process by which cells convert glucose into usable energy (ATP).

Glycolysis

The breakdown of glucose into two pyruvate molecules, producing 2 ATP and 2 NADH; occurs in the cytoplasm.

Pyruvate Oxidation

Conversion of pyruvate into Acetyl-CoA, releasing CO₂ and producing NADH.

Citric Acid Cycle (Krebs Cycle)

Takes place in the mitochondrial matrix; produces ATP, NADH, FADH₂, and CO₂.

Oxidative Phosphorylation

Uses the Electron Transport Chain and Chemiosmosis to make the bulk of ATP.

Electron Transport Chain

Electrons from NADH and FADH₂ pass through this chain in the inner mitochondrial membrane.

Chemiosmosis

The movement of protons that creates a gradient, powering ATP synthase to produce ATP.

Photosynthesis

Occurs in chloroplasts and consists of light-dependent and light-independent reactions.

Light-Dependent Reactions

Occur in the thylakoid membranes; use sunlight to produce ATP and NADPH.

Calvin Cycle (Light-Independent Reactions)

Occurs in the stroma; uses ATP and NADPH to fix CO₂ into glucose.

Temperature (Enzyme Activity)

Too high can denature enzymes; too low slows activity.

pH (Enzyme Activity)

Each enzyme works best at a certain pH level.

Substrate Concentration (Enzyme Activity)

Increasing it can boost reaction rate, but only up to a certain point.