Chapter 9

STUDY
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Fermentation
Partial degradation of sugars that occurs without oxygen
Aerobic Respiration
Consumes organic molecules and oxygen and yields ATP
Anaerobic Respiration
Similar to aerobic respiration, but consumes compounds other than oxygen
Cellular Respiration
Includes both aerobic and anaerobic respiration (but is often used to refer to just aerobic respiration)
Redox Reactions
(Oxidation-Reduction Reactions) Chemical reactions that transfer electrons between reactants
Oxidation
A substance loses electrons, or is oxidized
Reduction
A substance gains electrons, or is reduced (the amount of positive charge is reduced)
Reducing Agent
Electron Donor
Oxidizing Agent
Electron Receptor
NAD+
A coenzyme; electrons from organic compounds are usually first transferred here; electron acceptor and functions as an oxidizing agent during cellular respiration
NADH
The reduced form of NAD+ that represents stored energy that is tapped to synthesize ATP
Electron Transport Chain
Passes electrons in a series of steps instead of one explosive reaction with the help of NADH
Glycolysis
1st stage of cellular respiration; "Splitting of Sugar" - Glucose is broken down into 2 molecules of pyruvate; Has 2 major phases 1. Energy Investment Phase and 2. Energy Payoff Phase
Citric Acid Cycle
2nd stage of cellular respiration; Krebs Cycle; Takes place in the mitochondrial matrix; Has 8 steps, each catalyzed by a specific enzyme; Completes the breakdown of glucose
Oxidative Phosphorylation
3rd stage of cellular respiration; Accounts for most (almost 90%) of the ATP synthesis & is powered by redox reactions
Substrate Level Phosphorylation
A smaller amount of ATP is formed in glycolysis and the citric acid cycle by this
Acetyl CoA
Before the citric acid cycle can begin, pyruvate must be converted to this; Links the cycle to glycolysis
Cristae
Electron transport chain of the mitochondrion
Chemiosmosis
The use of energy in a H+ gradient to drive cellular work
Protonmotive Force
The H+ gradient; Emphasizes capacity to do work
Alcohol Fermentation
Pyruvate is converted to ethanol in 2 steps with the first releasing carbon dioxide
Lactic Acid Fermentation
Pyruvate is reduced by NADH, forming lactate as an end product with no release of carbon dioxide
Obligate Anaerobes
Carry out fermentation or anaerobic respiration and cannot survive in the presence of oxygen
Facultative Anaerobes
Can survive using either fermentation or cellular respiration, i.e. yeast and bacteria
Beta Oxidation
Fatty acids are broken down and yield acetyl CoA