Cellular Respiration

Cellular respiration

It is the aerobic harvesting of energy from food molecules by cells, producing ATP.

Breathing

Breathing involves gas exchange, while cellular respiration involves producing ATP from glucose.

Main stages of cellular respiration

Glycolysis, TCA (Krebs) Cycle, and Oxidative Phosphorylation.

Location of cellular respiration

In the mitochondria of eukaryotic cells.

ATP

ATP is the primary energy currency of the cell, used to power cellular processes.

High-energy molecule

It has high-energy phosphate bonds that release energy when broken.

Hexokinase

Hexokinase transfers a phosphoryl group from ATP to glucose, initiating glycolysis.

Glycolysis

Glucose is broken down into pyruvate, producing ATP and NADH.

Role of electrons in ATP production

Electrons falling from high to low energy states release energy used to make ATP.

Redox reaction

A reaction where one substance is oxidized (loses electrons) and another is reduced (gains electrons).

Glucose and oxygen during cellular respiration

Glucose is oxidized to CO₂; oxygen is reduced to H₂O.

ATP turnover management

ATP is continuously regenerated from ADP using energy from cellular respiration.

NAD+ and FAD

Coenzymes that act as electron carriers during cellular respiration.

NADH in cellular respiration

Transfers electrons to the electron transport chain to generate ATP.

Electron transport chain

A series of steps that pass electrons to oxygen, releasing energy to make ATP.

Aerobic vs anaerobic respiration

Aerobic uses oxygen and produces more ATP; anaerobic does not and yields less ATP.

Gradual energy release in cellular respiration

To prevent damage from sudden heat release and to efficiently capture energy.

Energy efficiency of cellular respiration

Only about 34% of the energy in glucose is captured as ATP.

Rest of the energy from glucose

It is lost as heat or used in other metabolic processes.