BIOL1406 ch7 How Cells Harvest Energy

Cellular Respiration

The process by which cells extract energy from organic molecules to produce ATP.

Autotrophs

Organisms that produce their own organic molecules, typically through photosynthesis.

Heterotrophs

Organisms that obtain organic compounds by consuming other organisms.

REDOX Reactions

Reduction-Oxidation reactions where electrons are transferred from one atom to another, involving oxidation (loss of electrons) and reduction (gain of electrons).

Oxidation

The process of losing electrons during a REDOX reaction.

Reduction

The process of gaining electrons during a REDOX reaction.

NAD+

Nicotinamide adenine dinucleotide, a common electron carrier in cellular respiration.

Phosphorylation

The process of adding a phosphate group to a molecule, often resulting in increased reactivity.

Glycolysis

The metabolic pathway that breaks down glucose into two molecules of pyruvate, occurring in the cytoplasm.

Citric Acid Cycle

Also known as the Krebs Cycle, it oxidizes acetyl CoA to produce ATP, NADH, and FADH2.

Chemiosmosis

The movement of protons (H+) across a membrane to generate ATP through ATP synthase.

Oxidative Phosphorylation

The final stage of cellular respiration where ATP is synthesized by utilizing the electron transport chain and a proton gradient.

Fermentation

A metabolic process that occurs in the absence of oxygen, allowing for the regeneration of NAD+ from NADH.

Lactic Acid Fermentation

The process where pyruvate is reduced to lactate, regenerating NAD+; occurs in some bacteria and human muscle cells.

Alcohol Fermentation

The process where pyruvate is split and reduced to ethanol and CO2, regenerating NAD+; occurs in yeasts.

Obligate Anaerobes

Organisms that carry out fermentation or anaerobic respiration and cannot survive in the presence of oxygen.

Facultative Anaerobes

Organisms that can survive using either fermentation or cellular respiration, depending on the availability of oxygen.

ATP Synthase

An enzyme that synthesizes ATP using the flow of protons (H+) across a membrane.

Dehydrogenation Reactions

Redox reactions in which an organic molecule loses hydrogen atoms (electrons) during the breakdown process.

Substrate-level Phosphorylation

The direct transfer of a phosphate group from a substrate to ADP to form ATP.

Decarboxylation

The removal of a carboxyl group from a molecule, resulting in the production of carbon dioxide.