IB Biology Topic C1.2: Cell Respiration Key Definitions

Active transport is the movement of molecules or ions across a membrane against their concentration gradient (from low to high concentration), which requires energy.

Anabolic reactions are metabolic processes in which smaller molecules are built into larger, more complex molecules using energy.

Anaerobic respiration is a form of respiration that occurs without oxygen.

ATP is a nucleotide, similar to those that make up DNA and RNA.

The enzyme that uses the energy from the proton gradient to catalyze the synthesis of ATP from ADP and inorganic phosphate.

Cell respiration is a series of metabolic processes that convert energy stored in carbon compounds, such as glucose and fatty acids, into ATP.

Chemiosmosis is the movement of protons ($H^+$) across a membrane, driven by a concentration gradient, to power the synthesis of ATP.

Condensation is a reaction where two molecules combine, releasing water.

A series of protein complexes embedded in the inner mitochondrial membrane.

The metabolic pathway that breaks down one molecule of glucose (6C) into two molecules of pyruvate (3C), producing a net gain of 2 ATP and 2 NADH. It occurs in the cytoplasm and does not require oxygen.

Hydrolysis is a chemical reaction where water ($H_2O$) breaks down a compound.

pH is a measure of how acidic or basic a solution is, ranging from 0 (very acidic) to 14 (very basic).

Phosphorylation refers to the addition of a phosphate group to a molecule

The Krebs cycle (also known as the citric acid cycle) occurs in the mitochondrial matrix and is a key part of aerobic respiration.