2.8 Cellular Respiration Flashcards
Cellular respiration
Process that converts the energy stored in NADH and FADH2 into ATP
Aerobic respiration
Uses oxygen as a reactant to produce energy
1 glucose + 6O2 produces 38 ATP, 6 CO2, and 6H2O
Anaerobic respiration
Turns glucose into energy (ATP or other energy-carrying molecules) in the absence of oxygen. Produces lactic acid or ethanol.
Fermentation is a form of anaerobic respiration
Primary products of aerobic respiration
Carbon dioxide and water
Steps of aerobic cellular respiration
- Glycolysis
- Pyruvate oxidation
- Krebs cycle (citric acid cycle)
- Electron transport chain
Glycolysis
Glucose undergoes a series of chemical transformations in which it is converted to 2 pyruvate molecules and yields a net of two ATP molecules
Acetyl CoA
Product of pyruvate being split into a two-carbon molecule and binding to coenzyme A. The carbon that is lost combines with oxygen to produce carbon dioxide as a waste product
CoA
Coenzyme A
Carries pyruvate to the mitochondria where it is transformed into acetyl CoA to begin the Krebs cycle
Electron transport chain (in aerobic respiration)
High energy electrons are released from NADPH and FADH2 to generate more ATP. Most of ATP is produced during this stage
ATP synthase
Makes use of the hydrogen ion (proton) gradient created by the other parts of the e- transport chain to form ATP from ADP and a free phosphate group
Total energy production of aerobic respiration
38 molecules of ATP per molecule of glucose
Role of oxygen in e- transport chain
Collects e- at the end of the chain and combines them with hydrogen ions to make water.
In the absence of oxygen the ETC becomes saturated with e- and backs up the process down to the Krebs cycle
Lactic acid fermentation
Instead of pyruvate entering the Krebs cycle, the e- released by glycolysis are added to the pyruvate to produce lactic acid
