Module 7 Flashcards
Cellular Respiration
A series of chemical reactions in which organic molecules are oxidized to carbon dioxide, converting the energy stored in organic molecules to ATP.
Oxidative Phosphorylation
A set of metabolic reactions that occurs by passing electrons from reduced electron carriers along an electron transport chain to the final electron acceptor, oxygen, pumping protons across a membrane, and using the proton electrochemical gradient to drive the synthesis of ATP.
Electron Transport Chain
The system that transfers electrons along a series of membrane-associated proteins from an electron donor to a final electron acceptor.
Nicotinamide Adenine Dinucleotide (NAD)
An electron carrier that produces 2.5 molecules of ATP via the ETC.
Glycolysis
The breakdown of glucose to pyruvate. Anaerobic.
Pyruvate Oxidation
Pyruvate is oxidized to another molecule called acetyl-coenzyme A (acetyl-CoA), producing reduced electron carriers and releasing carbon dioxide.
Adenosine Triphosphate (ATP)
The main source of energy in cells.
Proton Gradient
A difference of charges between membranes.
Fermentation
A process for extracting energy from fuel molecules that does not rely on oxygen or an electron transport chain but instead uses an organic molecule as an electron acceptor.
Lactic Acid Fermentation
The fermentation pathway in animals and bacteria during which electrons from NADH are transferred to pyruvate, producing lactic acid and NAD+.
Ethanol Fermentation
The fermentation pathway in plants and fungi in which the product of glycolysis, pyruvate, undergoes decarboxylation (carbon dioxide is removed) to form acetaldehyde. This is followed by transfer of electrons from NADH to acetaldehyde, resulting in ethanol and NAD+.
Glycogen
The form in which glucose is stored in animals.
Monosaccharide
One sugar.
Beta-Oxidation
The process of shortening fatty acids by a series of reactions that sequentially remove two carbon units from their ends. Doesn’t produce ATP but produces NADH and FADH2. End product is acetyl-CoA which enters the citric acid cycle.
Substrate-Level Phosphorylation
A phosphate group is transferred to ADP from an organic molecule which acts as a phosphate donor or substrate. The process by which ATP is synthesized by a hydrolysis reaction involving an enzyme/substrate complex.
Electron Carriers
A molecule that carries electrons (and energy) from one set of reactions to another.
Oxidation-Reduction Reactions (REDOX Reactions)
Chemical reactions in which electrons are transferred from one atom or molecule to another.
Flavin Adenine Dinucleotide (FAD)
An electron carrier that produces 1.5 molecules of ATP via ETC.
Citric Acid Cycle/Krebs Cycle/Tricarboxylic Acid Cycle (TCA Cycle)
Acetyl-CoA is broken down and carbon dioxide is released.
Mitochondria
Where the final 3 stages of cellular respiration occur.
Intermembrane Space
The space between the inner and outer mitochondrial membranes.
Mitochondrial Matrix
The space enclosed by the inner membrane of the mitochondria.
ATP Synthase
An enzyme that couples the movement of protons through the enzyme with the synthesis of ATP. Converts one form of energy into energy in the bonds of ATP.
Aerobic
Requires oxygen.
Anaerobic
Does not require oxygen.
Starch
The storage forms of carbohydrates in plants.
Disaccharide
Two sugars.
Fatty Acid
A long chain of reduced carbons attached to a carboxyl group.
Oxidation
Loss of electrons.
Reduction
Gain of electrons.
Oxidized
The molecule that loses electrons.
Reduced
The molecule that gains electrons.
Stages of Cellular Respiration
1) Glycolysis
2) Pyruvate Oxidation
3) Citric Acid Cycle
4) Oxidative Phosphorylation
Coenzyme Q (CoQ)
A mobile electron acceptor that transports electrons from complexes I and II to complex III in the electron transport chain and moves protons from the mitochondrial matrix to the intermembrane space.
Cytochrome c
The enzyme to which electrons are transferred from complex III of the respiratory electron transport chain to complex IV.
Fo Subunit
Forms a channel that rotates as protons pass through it.
F1 Subunit
Uses the rotational energy to catalyze the synthesis of ATP.
Chemiosmosis
The movement of ions from a region of high concentration to a region of low concentration across a selectively permeable membrane.
Phosphofructokinase-1 (PFK-1)
The enzyme that catalyze the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate. AMP and ADP activate the protein. ATP inhibits the protein. Citrate is an allosteric inhibitor of the enzyme.
Phases of Glycolysis
1) Preparatory Phase (where energy is consumed)
2) Cleavage Phase (where glucose is split into two)
3) Payoff Phase (where ATP is one of the products)
Pyruvate Dehydrogenase
A group of enzymes used in pyruvate oxidation.
Preparatory Phase
Using 2 ATPs to produce fructose 1,6-bisphosphate.
Cleavage Phase
Splitting the fructose 1,6-bisphosphate to 2 glyceraldehyde.
Payoff Phase
Produce 4 ATP, 2 NADH, and 2 pyruvate.
