Cellular Respiration and Mitochondrial Function

Mitochondria

Cellular organelles that generate ATP through cellular respiration.

Cellular Respiration

The process by which cells harvest chemical energy stored in organic molecules to generate ATP.

Organic molecules + oxygen

Reactants that yield CO2 + H2O + energy during cellular respiration.

Starch

The major source of fuel for animals, which breaks down into glucose.

Oxidized

The process of losing electrons, as seen in the catabolic breakdown of glucose.

Reduction

The process of gaining electrons, as seen when NAD+ is reduced to NADH.

OIL RIG

A mnemonic for oxidation is loss, reduction is gain.

C6H12O6 + 6O2

The chemical equation representing glucose oxidation during cellular respiration.

6CO2 + 6H2O + energy

The products of glucose oxidation in cellular respiration.

Path of Electrons in Energy Harvest

The sequence of glucose → NADH → ETC → oxygen during cellular respiration.

Electron Transport Chain (ETC)

A sequence of membrane proteins that shuttle electrons down a series of redox reactions.

Stages of Cellular Respiration

Three stages: Glycolysis, Pyruvate oxidation and the citric acid cycle, Oxidative phosphorylation.

Glycolysis

The first stage of cellular respiration that occurs in the cytosol and splits glucose into 2 pyruvates.

Energy Investment Stage

The phase of glycolysis where ATP is used to phosphorylate glucose compounds.

Energy Payoff Stage

The phase of glycolysis where energy is produced by substrate-level phosphorylation.

Net Energy Yield per 1 Glucose

2 ATP and 2 NADH produced from glycolysis.

Pyruvate Oxidation

The process where pyruvate is oxidized into acetyl coA if oxygen is present.

Citric Acid Cycle

Also known as the Krebs cycle, it occurs in the mitochondrial matrix and processes acetyl CoA.

Citric Acid Cycle Outputs

2 ATP, 6 NADH, 4 CO2, and 2 FADH2 produced per glucose molecule.

Quick Check - Glycolysis Occurrence

Glycolysis occurs in the cytosol.

Quick Check - Glycolysis Production

Glycolysis produces pyruvate.

Quick Check - Net Production of ATP

The net production of ATP from glycolysis is 2 ATP.

Quick Check - Citric Acid Cycle Occurrence

The citric acid cycle occurs in the mitochondrial matrix.

Oxidative Phosphorylation

Process generating ATP via electron transport chain.

Cristae

Folds in mitochondria increasing surface area.

Proton Gradient

H+ concentration difference across mitochondrial membrane.

Final Electron Acceptor

Oxygen, forming water with electrons and protons.

Chemiosmosis

Process using H+ gradient to synthesize ATP.

ATP Synthase

Enzyme converting ADP + P into ATP.

Anaerobic Respiration

ATP generation without oxygen using ETC.

Fermentation

ATP production without ETC, recycles NAD+.

Alcohol Fermentation

Conversion of pyruvate to ethanol by yeast.

Lactic Acid Fermentation

Conversion of pyruvate to lactate in muscles.

Lactic Acidosis

Condition from lactate buildup lowering blood pH.

NADH

Electron carrier generated in glycolysis and Krebs.

FADH2

Another electron carrier produced in Krebs cycle.

Total ATP Yield

30-32 ATP produced per glucose molecule.

Exergonic Flow

Energy-releasing movement of electrons in ETC.

Hydrogen Ions (H+)

Protons pumped into intermembrane space during ETC.

Oxygen's Role

Drives electron flow in the electron transport chain.

Muscle Cells

Use lactic acid fermentation when oxygen is low.

Shimmying

Muscle reaction in fish due to oxygen deprivation.

pH Effect

Influences ion concentration and mitochondrial activity.

Mitochondrial Permeability

Outer membrane's ability to allow H+ passage.

ATP Production

Energy currency generated during cellular respiration.