Key Knowledge 5 Flashcards
cellular respiration
the process by which cells create usable energy in the form of ATP from a series of biochemical reactions, involving the breakdown of glucose
cellular respiration equation
glucose + oxygen —> carbon dioxide + water + energy
C6H12O6 + 6 O2 —> 6 CO2 + 6 H2O + 36 or 38 ATP
Animals: lactic acid fermentation
Glucose —> Lactic acid + ATP
C6H12O6 2 C3H6O3 2 ATP
Plants and yeast: alcohol fermentation
Glucose —> Ethanol + Carbon dioxide + ATP
C6H12O6 C2H5 H 2 CO2 2 ATP
glycolysis
the first stage of aerobic cellular respiration in which glucose is converted to two pyruvate molecules. location is in the cytosol
Krebs cycle
the second stage of aerobic cellular respiration, where multiple reactions occur to create ATP, NADH, FADH2, and the waste product CO2. Also known as the citric acid cycle or TCA cycle. The location is in the mitochondrial matrix
electron transport chain
the third stage of aerobic cellular respiration, in which a series of protein complexes embedded in the inner membrane of a mitochondrion harness the stored energy in NADH and FADH2 to generate large amounts of ATP. The location is the cristae of the mitochondria
Mitochondria
crucial to aerobic cellular respiration as they are the site of the second and third stages, with the first stage (glycolysis) occurring in the cytosol of the cell.
glycolysis inputs
- 1 glucose (C6H12O6)
- 2 ADP + 2 Pi
- 2 NAD+ + 2 H+
glycolysis outputs
- 2 pyruvate
- 2 ATP
- 2 NADH
krebs cycle inputs
- 2 acetyl-CoA (derived from 2 pyruvate)
- 2 ADP + 2 Pi
- 6 NAD + 6 H+
- 2 FAD + 4 H+
Krebs cycle outputs
- 4 carbon dioxide (CO2)
- 2 ATP
- 6 NADH
- 2 FADH2
overall results from krebs cycle
- By breaking down acetyl-CoA, protons and high-energy electrons are released. These protons and electrons are loaded onto NAD+ and FAD molecules to generate high-energy coenzymes NADH and FADH2.
- The Krebs cycle produces two CO2 molecules for every one acetyl-CoA molecule. When added to the single CO2 molecule produced from each of the two pyruvates undergoing the link reaction, this means a total of six CO2 molecules are produced for every original glucose molecule.
- The Krebs cycle produces a small amount of energy in the form of two ATP (one per acetyl-CoA molecule).
ETC inputs
- 6 oxygen (O2) + 12 H+
- 26 or 28 ADP + Pi
- 10 NADH
- 2 FADH2
ETC outputs
- 6 water (H2O)
- 26 or 28 ATP
- 10 NAD+ + 10 H+
- 2 FAD + 4 H+