Chapter 9 - Respiration Flashcards
The most efficient catabolic pathway in which oxygen is conservative as a reactant along with organic fuel
Aerobic respiration
Partial degradation of sugars or other organic fuel that occurs without the use of oxygen
Fermentation
Catabolic pathways of aerobic and anaerobic respiration which break down organic molecules and use an electron transport chain for the production of ATP
Cellular respiration
A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another (reduction-oxidation)
Redox reaction
Loss of electrons from one substance
Oxidation
Gain of electrons to a substance
Reduction
Electron donor
Reducing agent
Electron acceptor
Oxidizing agent
A coenzyme that cycles easily between oxidized (NAD+) and reduced (NADH) states, thus acts as an electron carrier
NAD+
Consists of a number of molecules (mostly proteins) built into the inner membrane of eukaryotic cells’ mitochondria (and plasma membrane of prokaryotes); it breaks the fall of electrons to oxygen into severs energy-releasing steps
Electron transport chain
Occurs in cytosol; begins degradation process by breaking glucose into two molecules of pyruvate
Glycolysis
Chemical cycle with 8 steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA to CO2; occurs in mitochondria of eukaryotes and cytosol of prokaryotes
Citric Acid Cycle
ATP production using energy derived from the redox reactions of an electron transport chain
Oxidative Phosphorylation/Electron Transport System
Enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism
Substrate-level phosphorylation
Entry compound for the citric acid cycle in cellular respiration formed from two-carbon fragment of pyruvate attached to a coenzyme
Acetyl CoA
An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membrane of prokaryotes
Cytochromes
Enzyme that makes ATP from ADP and Pi; works like an ion pump running in reverse (uses the energy of an existing ion to power ATP synthesis)
ATP synthase
Process in which energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work (such as ATP synthesis)
Chemiosmosis
Potential energy stored in the form of a proton electro chemical gradient, generated by the pumping of H+ ions across a biological membrane during chemiosmosis
Proton motive force
Pyruvate is converted to ethanol by releasing CO2 from pyruvate, which is converted to the 2-carbon compound acetylaldehyde. Then acetylaldehyde is reduced by NADH to ethanol. This regenerates the supply of NAD+ needed for glycolysis continuation
Alcohol fermentation
Pyruvate is reduced directly by NADH to form lactate as an end product with no release of CO2
Lactic acid fermentation
Organisms that cannot survive in the presence of oxygen; carry out only fermentation or anaerobic respiration
Obligate anaerobes
Organisms (like yeast and bacteria) that can make enough ATP to survive using either fermentation or respiration (ex: our muscle cells)
Facultative anaerobes
A metabolic sequence that breaks fatty acids down to 2-carbon fragments that enter the citric acid cycle as CoA. Also generates NADH and FADH2 which can enter the electron transport chain and lead to further ATP production
Beta oxidation
Glycolysis Inputs/Outputs
Inputs: 1 Glucose, 2 ATP, 2 NAD+
Outputs: 2 Pyruvate, 4 ATP, 2 NADH
Oxidation of Pyruvate Inputs/Outputs
Inputs: 2 Pyruvate, 2 NAD+, CoA
Outputs: 2 Acetyl CoA, 2 CO2, 2 NADH
Citric Acid Cycle Inputs/Outputs
Inputs: 2 Acetyl CoA, 2 ADP + Pi, 6 NAD+, 2 FAD
Outputs: 4 CO2, 2 ATP, 6 NADH, 2 FADH2
Electron Transport System Inputs/Outputs
Inputs: 10 NADH, 2 FADH2, 30 ADP + 30 Pi + O2
Outputs: 10 NAD+, 2 FAD, 30 ATP + H2O
