CH 9 Flashcards
Fermentation
-a partial degradation of sugars that occurs without O2
Aerobic respiration
-consumes organic molecules and O2 and yields ATP
Anaerobic respiration
-similar to aerobic respiration but consumes compounds other than O2
Cellular respiration
-includes both aerobic and anaerobic respiration but is often used to refer to aerobic respiration
Redox reactions (oxidation-reduction reactions)
-chemical reactions that transfer electrons between reactants
Oxidation
-a substance losses electrons, or is oxidized
Reduction
-a substance gains electrons, or is reduced (positive charge)
Reducing agent
-electron donor
Oxidizing agent
-electron receptor
NAD+
-functions as an oxidizing agent during cellular respiration
-a coenzyme
-electron acceptor
NADH
-reduced form of NAD+
Electron transport chain
-consists of several molecules/proteins built into the inner membrane of mitochondria of eukaryotic cells (plasma membranes of respiring prokaryotes)
-major step in Oxidative phosphorylation
-final electron acceptor = oxygen
Glycolysis
-breaks down glucose into two molecules of pyruvate
Where does Glycolysis take place?
- in the cytosol of the cell
what are the starting and end products of Glycolysis?
-starts with glucose
-ends with pyruvate
what are glycolysis’s energy inputs and outputs?
-input– 2 ATP
-output– 4 ATP, 2 NADH, & 2 pyruvate molecules
What is the key allosteric enzyme that regulates cellular respiration in glycolysis?
-dehydrogenase and NAD+
where does the conversion of pyruvate to Acetyl-CoA take place?
-in the mitochondria
what are the inputs and outputs of pyruvate to Acetyl-CoA?
- inputs– 2 pyruvates, 2 CoA, 2 NAD+
-outputs– 2 Acetyl CoA, 2 CO2, 2 NADH
conversion of pyruvate to Acetyl-CoA starting and end products?
-starting–pyruvate
-ending–Acetyl CoA
Citric Acid Cycle (Krebs cycle)
-completes the breakdown of pyruvate to CO2
where does the Citric Acid Cycle take place?
-mitochondria
starting and end products of the Citric Acid Cycle
-starting– Acetyl CoA and citrate
-ending– Oxaloacetate
energy outputs of the Citric Acid Cycle
- 1 ATP, 3 NADH, 1FADH2 per cycle
waste outputs of the Citric Acid Cycle
- 2 CO2
Oxidative phosphorylation
-process that generates almost 90% of the ATP
-powered by redox reactions
substrate-level phosphorylation
-forms small amounts of ATP in glycolysis and citric acid cycle
Cytochromes
-remaining electrons between ubiquinone and oxygen
-proteins
ATP synthase
-the enzyme that creates ATP
Chemiosmosis
-the process in which energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work
-EX. synthesis of ATP
Proton-motive force
-a force created by the transfer of protons or electrons across a membrane
Alcohol fermentation
-where pyruvate is converted to ethanol
Lactic acid fermentation
-where pyruvate is reduced by NADH, forming NAD+ and lactate as end products with no release of CO2
Obligate anaerobes
-carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
Facultative anaerobes
-they can survive using either fermentation or cellular respiration
-EX. yeast
Beta oxidation
-metabolic sequence
-breaks down fatty acids
-yields Acetyl CoA, NADH, & FADH2
