Campbell Biology Chapter 9: Cellular Respiration

fermentation

a catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid

aerobic respiration

a catabolic pathway that consumes oxygen gas and organic molecules, producing ATP

cellular respiration

the catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP

redox reaction

a chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another

oxidation

the loss of electrons from a substance involved in a redox reaction

reduction

the addition of electrons to a substance involved in a redox reaction

reducing agent

the electron donor in a redox reaction

oxidizing agent

the electron acceptor in a redox reaction

NAD+

a coenzyme that can accept an electron and acts as an electron carrier in the electron transport chain

electron transport chain

a sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP

glycolysis

the splitting of glucose into pyruvate; serves as the starting point for fermentation or cellular respiration

citric acid cycle

an eight-step series of reactions that completes the metabolic breakdown of glucose molecules by oxidizing pyruvate to carbon dioxide

oxidative phosphorylation

the production of ATP using energy derived from the redox reactions of an electron transport chain

substrate-level phosphorylation

the formation of ATP by an enzyme directly transferring a phosphate group to ADP from an intermediate substrate in catabolism

acetyl CoA

the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme

ATP synthase

enzyme that makes ATP from ADP and inorganic phosphate; uses the energy of a hydrogen ion (proton) concentration gradient to make ATP

chemiosmosis

an energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP

proton-motive force

the potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis

obligate anaerobes

carry out fermentation or anaerobic respiration and cannot survive in the presence of O2

facultative anaerobes

carry out fermentation or anaerobic respiration and cannot survive in the presence of O2; pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes

beta oxidation

a metabolic sequence that fatty acids down to two-carbon fragments that enter the citric acid cycle as acetyl CoA

NADH

Oxidized form of NAD that temporarily accepts electrons during cellular respiration

Autotroph

Uses energy from the sun or from oxidation of inorganic substances to make organic molecules from inorganic ones.

Heterotrophs

Unable to make there own food, they live on compounds produced by other other organisms. (hetero - "other")

Oxidation

removal of electrons (Hydrogen, adding Oxygen)

Reduction

addition of electrons (Gains Hydrogen)

Redox reactions

Oxidation and reduction happening at the same time.

Cytosol

Fluid portion of cytoplasm

Cristae

folds in the inner membrane of mitochondria

Matrix

the space inside the inner membrane of the mitochondria

Intermembrane space

between inner and outer membranes of mitochondrion

Fermentation

final electron acceptor is an organic compound

proton pumps

Active transport of H+ molecules across membranes occurs through

lactic acid fermentation

Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD+ with no release of carbon dioxide.

alcoholic fermentation

Glycolysis releases carbon dioxide from pyruvate, which is converted to acetaldeyde. Acetaldehyde is reduced by NADH to ethanol regenerating the supply of NAD+.