Cellular metabolic pathways

ATP

Adenosine Triphosphate, the primary energy source for cellular processes.

High-Energy Phosphate Bonds

Bonds in ATP that release energy when a phosphate group is removed.

Substrate-Level Phosphorylation

Direct production of ATP by adding a phosphate group to ADP from a phosphorylated substrate.

Glycolysis

The breakdown of carbohydrates occurring in the cytosol, producing 2 ATP per glucose molecule.

Aerobic Glycolysis

Glycolysis in the presence of oxygen, producing NADH and pyruvate.

Anaerobic Glycolysis

Glycolysis without oxygen, producing lactate and only 2 ATP.

Krebs Cycle

Further breakdown of pyruvate in the mitochondria, producing 2 ATP and electron carriers.

NADH and FADH₂

Electron carriers produced in the Krebs cycle used in the electron transport chain.

Electron Transport Chain (ETC)

The final destination for NADH and FADH₂, generating 28-34 ATP and water.

Oxidative Phosphorylation

The process of forming ATP from ADP using energy from electron flow in the ETC.

Plasma Membrane

A selective barrier controlling the entry and exit of substances in and out of the cell.

Lipid Bilayer

The structure of the plasma membrane composed of two layers of phospholipids.

Permeability

The ability of the plasma membrane to allow certain substances to pass through.

Transport Proteins

Proteins that facilitate the movement of molecules across the plasma membrane.

Diffusion

The movement of molecules from high to low concentration without energy input.

Passive Transport

Movement of substances across the membrane without the use of energy.

Osmosis

The net movement of water across a semipermeable membrane from lower to higher solute concentration.

Isotonic Solution

A solution where the concentration of solutes is equal inside and outside the cell, maintaining cell size.

Hypertonic Solution

A solution with a higher concentration of solutes outside the cell, causing it to shrink.

Hypotonic Solution

A solution with a lower concentration of solutes outside the cell, causing it to swell.

Osmotic Pressure

The pressure required to stop the net flow of water across a semipermeable membrane.

Carrier-Mediated Transport

The process where proteins transport molecules across the membrane, regulated by binding.

Facilitated Diffusion

Movement of molecules down their concentration gradient with the help of carrier proteins, without energy.