Lecture 8: Cellular respiration Flashcards
Photosynthesis occurs…
in plants only
Cellular respiration occurs…
in plants/animals
ATP powering cellular work:
ATP -> ADP breaks a phosphate bond which releases energy
Major energy requirements of the cell:
- mechanical work
e. g. motor proteins - make new materials
e. g. growth & replacement - transport
e. g. molecules across membranes - maintain order
Mitochondria:
site of cellular respiration
Equation for breaking down glucose and the release of energy:
C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy
Mitochondrion structure:
1-10 micrometers
1-1000 per cell
contains mitochondrial DNA/ribosomes
Mitochondrion membrane:
two membranes
- inner membrane highly folded (cristae)
mitochondrial matrix inside inner membrane
- outer membrane
Cellular respiration:
harvests chemical energy from glucose
Cellular respiration:
stage 1 - glycolysis (in cytosol)
- glucose is converted to pyruvate
- generates:
2 ATP
2NADH - high energy electron carrier (derived from NAD+
Cellular respiration stage 2 (in mitochondrial matrix) - pyruvate oxidation & citric acid cycle
- pyruvate converted into Acetyl CoA
- Acetyl CoA enters citric acid cycle
- output ATP/NADH &FADH2 high energy electron carriers
Cellular respiration
stage 3 - Oxidative phosphorylation
part 1: electron transport chain
- Electron carriers take electrons to inner mitochondrial membrane
- electrons move through protein complexes
- this movement powers protons to be pumped across membrane, forming gradient
Cellular respiration
stage 3 - Oxidative phosphorylation
part 2: chemiosmosis
- proton gradient powers ATP synthesis
- synthesis converts ADP + Pi -> ATP
consumed/formed in cellular respiration:
Consumed: - glucose - oxygen formed: - carbon dioxide - water - ATP
ATP enables…
controlled release of energy
