Glycolysis Flashcards
Aerobic respiration
Breakdown of glucose using oxygen
—-> water, CO2, Energy
Cellular respiration:
C6H12O6 + 6O2 —> 6CO2 + 6H2O + E (from bonds of glucose)
1) Cytoplasm & Mitochondrion
2) Substrate level phosphorylation (glycolysis) + Oxidative phosphorylation (cellular respiration)
Glycolysis (overview)
Biological pathway
Cytoplasm
Harvest portion of energy from glucose
Rest with Krebs cycle
1 glucose: 2 G3P
2 ATP (4 produced - 2 consumed at beginning)
2 pyruvate (3-C molecules)
2 NADH reduced)
3 steps: photo
1) Priming rxn (prime glucose with input of energy — input 2 ATP)
2) Cleavage (phosphorylated glucose - phosphate from ATP - cleaved into two 3-C sugars)
3) Oxidation, ATP formation, Energy Generation
- oxidation of 3-C sugar = 2 NADH
- phosphate added to each sugar
- substrate level phosphorylation =
2 ATP
Glycolysis (10 steps)
1) Priming rxn
- Glucose phosphorylation (requires energy)
6-C Glucose + phosphate (ATP) = glucose 6- phosphate + ADP - Isomerization (no energy required)
Glucose 6-phosphate
——> fructose 6-phosphate
Structural isomers - Fructose phosphorylation (requires energy)
Fructose 6-phosphate + phosphate (ATP) = fructose 1,6-biphosphate
2) Cleavage
- Cleavage
Fructose 1,6 biphosphate = G3P + its isomer (dihydroxyacetone phosphate) - Isomerization
Isomer of G3P —-> G3P (glyceraldehyde 3-phosphate)
Two G3P: rest of rxn happen in double
3) Energy Generation
- Oxidation
G3P oxidized: NAD+ + 2e- + 2H+ —-> NADH + H+ (release of energy)
2 NADH (2 G3P = 1 glucose)
Energy from redox rxn:
G3P + phosphate —-> 1,3-biphosphoglycerate
- ATP formation
1,3 biphosphoglycerate - phosphate (to ADP) = 3-phosphoglycerate & ATP
2 ATP (2G3P = 1 glucose) - Isomerization
Transfer of phosphate from carbon-3 to carbon-2
3-phosphoglycerate —-> 2-phosphoglycerate - Dehydration
2-phosphoglycerate - 1 water = PEP
*important for pyruvate (for NADH & ATP) - Formation of ATP & Pyruvate
PEP - phosphate (to ADP) = pyruvate & ATP
2 pyruvate, 2 ATP (2 G3P = 1 glucose)
