Biology 2E Chapter 7: Cellular Respiration

A comprehensive set of vocabulary flashcards covering the metabolic pathways and regulatory mechanisms of cellular respiration as described in Chapter 7.

Cellular Respiration

The process by which cells extract energy from food to generate $ATP$ through glucose catabolism.

Redox Reactions

Chemical reactions characterized by the transfer of electrons from one molecule to another.

Reducing Agent

A molecule that can donate electrons in a redox reaction.

Oxidizing Agent

A molecule that can accept electrons in a redox reaction.

Reduction

The process by which a molecule gains one or more electrons after a chemical reaction.

Oxidation

The process by which a molecule loses one or more electrons during a chemical reaction.

Electron Carrier

Molecules like $NAD^+$ or $FAD^+$ that shuttle high-energy electrons to electron transport chains where $ATP$ is produced.

Dephosphorylation

The chemical process involving the loss of a phosphate group from a molecule.

Phosphorylation

The process of adding a phosphate group to a molecule, which often makes the molecule less stable and more reactive.

Substrate-Level Phosphorylation

A method of generating $ATP$ via a coupled exergonic reaction that does not require a membrane.

Chemiosmosis

A process for making $ATP$ that requires the enzyme $ATP\text{ synthase}$ and a $H^+$ concentration gradient; it produces $90$% of $ATP$ during glucose catabolism.

Glycolysis

The first metabolic pathway of glucose metabolism, occurring in the cytoplasm, which breaks down one glucose into two pyruvate molecules.

Glyceraldehyde-3-phosphate (G3P)

The two three-carbon molecules formed when glucose is phosphorylated and split during the first half of glycolysis.

Acetyl CoA

The molecule formed in the mitochondria when pyruvate is oxidized and coenzyme A is attached before entering the Citric Acid Cycle.

Citric Acid Cycle (CAC)

A series of reactions in the mitochondrial matrix where citrate is oxidized to produce $NADH$, $FADH_2$, and $ATP$ or $GTP$.

Oxaloacetate

The four-carbon molecule that is the final product of the Citric Acid Cycle and combines with the acetyl group to start the cycle again.

Oxidative Phosphorylation

The final stage of cellular respiration consisting of the electron transport chain and chemiosmosis.

Electron Transport Chain (ETC)

A series of transporters embedded in the inner mitochondrial membrane that shuttle electrons from $NADH$ and $FADH_2$ to $O_2$.

Ubiquinone (Q)

A mobile electron carrier that shuttles electrons from complexes I and II to complex III in the electron transport chain.

Cytochrome C

A peripheral protein that carries individual electrons to complex IV of the electron transport chain.

ATP synthase

A complex integral protein that uses the kinetic energy from protons falling down a gradient to form $ATP$ from $ADP$ and $P_i$.

Lactic Acid Fermentation

An anaerobic process occurring in muscle cells and some bacteria where pyruvate is converted to lactate to regenerate $NAD^+$.

Alcohol Fermentation

An anaerobic process used by yeast where pyruvate is converted into $CO_2$, acetaldehyde, and finally ethanol.

Glut4

Vesicles that fuse with the plasma membrane in the presence of insulin to allow glucose to enter the cell.

Hexokinase

The glycolysis enzyme affected by feedback inhibition from elevated levels of glucose-6-phosphate.