Aerobic System Flashcards
NADH+H and FADH2
enzymes that carry H to the ETC.
- accept 2H and dump e- into ETC
aerobic system
biochemical pathways complete breakdown of glucose/glycogen, fats, some AA to make lots of energy.
energy harnessed rephorphorylates ADP to ATP
- O2 used; CO2 and H2O byproducts
components of aerobic pathway
aerobic glycolysis
krebs cycle
beta oxidation
ETC
aerobic glycolysis
HK turn glucose into G6P / PHOS turn glycogen to G6P
G6P > F6P
F6P > F1,6P via PFK
F1,6P > GA3P > 3PG (make NADH) > pyruvate
pyruvate into membrane (protein carrier) > Acetyl coA via PDH (make NADH)
(See notes for Diagram)
hexokinase (HK)
enzyme that turns glucose into G6P during aerobic glycolysis
- uses an ATP
phosphorylase (PHOS)
enzyme turn glycogen into G1P during aerobic glycolysis
phosphofructokinase (PFK)
enzyme turn F6P into F1,6P during aerobic glycolysis
- rate limiting step of glycolysis
- inhibited by: ATP and citrate
- activated by: ATP
pyruvate dehydrogenase (PDH)
enzyme convert pyruvate to Acetyl-coA once inside the mitochondrial membrane
formation of Acetyl-coA
pyruvate (CCC) decarboxylated into acetic acid (CC) (+ CO2)
PDH dehydrogenases acetic acid (CC) to make NADH+H, adds coenzyme A to make Acetyl-coA (CC)
- irreversible
- not use O2 directly, must be aerobic
aerobic krebs cycle
1: acetyl-coA (2C) + oxaloacetate (4C) = citrate via citrate synthase
2: citrate (6C) > isocitrate (6C) via aconitate
3: isocitrate (6C) > alpha-Ketoglutarate (5C) via IDH (also make CO2, NADH+H)
4: a-Ketoglutarate (5) > succinyl CoA (4C) via a-KDH (make CO2, NADH+H)
5: succinyl Co-A (4C) > succinate (4C) (ADP > ATP)
6: succinate (4C) > Furamarate (4C) (make FADH2)
7: H2O added to Furamarate > Malate (4C)
8: Malate (4C) < oxaloacetate (4C) (make NADH+H)
Summary of out comes of Aerobic Kreb Cycle
Not direct use of )2 but must be aerobic
2 ATP
6 NADH+H (3,4,8)
2 FADH2 (6)
4 CO2
Limiting enzyme = IDH
citrate synthase
Oxaloacetate + Acetyl CoA –> Citrate
- step 1 of aerobic glycolysis
isocitrate dehydrogenase (IDH)
isocitrate -> alpha-ketoglutarate, decarboxylation that generates NADH and CO2
- step 3 of aerobic glycolysis, rate limiting factor
- activated by Ca and ADP
alpha-ketoglutarate dehydrogenase (a-KDH)
enzyme that turns alpha-ketoglutarate (5C) to succinyl-CoA (4C)
- makes NADH+H and CO2
- stimulated by ADP and Ca
- step 4 of aerobic glycolysis
The Electron Transport Chain
Embedded in the inner membrane of the mitochondria
NADH+H > complex 1 > Q > complex 3 > cytochrome c > complex 4 > O2
FADH2 > Complex 2 > Q > complex 3 > cytochrome c > complex 4 > O2
cytochrome oxidase
enzyme at step 4 of ETC that is rate limiting.
- turns 1/2 O2 + 2H = H2O
electron transport chain (ETC) Steps
1: NADH+H at comp1 put e- into complex, drop H at mitochondrial matrix
1a: if FADH not NADH, drop into comp2
2a: e- shuttle down cytochromes to alt gain/lose e-
2b: e- also move along inner membrane cause p+ pumps move H from matrix to inner membrane
3: O2 accept e-; add H = H2O
4: H in intermembrane cause gradient, so sneak into matrix via ATP synthase; this energy cause ADP+P=ATP
5: ATP to intermembrane thru ATP-ADP antiporter protein, also bring in ADP
6: ATP out of mitochondria in exchange for inward ADP
ATP-ADP antiporter protein
in step 5 of ETC this antiporter protein sends ATP to intermembrane space (later leave mitochondria) and brings ADP from intermembrane to matrix
fat metabolism
- can only be metabolized aerobically
- come from either FFA+albumin or stored triglycerides
- brain cannot metabolize FA (too long for BBB)
lipolysis in adipocytes
epinepherine stimulates hormone sensitive lipase to turn triglycerides into glycerol.
Liver then turns glycerol into glucose via gluconeogenesis
beta oxidation
reaction that converts fatty acids to acetyl CoA to enter the Krebs cycle
beta oxidation steps
FA enter muscle attached to albumin thru FATP
1: FA + CoA-SH = activated FA via fatty acyl-coA synthase (uses ATP)
2: FAD > FADH, go to ETC to make 1.5 ATP
3: H2O added, NAD > NADH, to to ETC make 2.5ATP
4: activated FA > acetyl coA via 3HAD, go to Krebs
5: activated FA + Coa-SH ; steps 1-4 repeated until last product is acetyl-coA
beta oxidation of fatty acids
fatty acid tails are continuously broken down by coA-SH until there are none left, which results in acetyl coA itself (2C)
3-HAD
3-hydroxyacyl-CoA dehydrogenase
- cleaves C off of activated FA to make acetyl-coA, which goes to the Krebs cycle (aerobic)
- rate limiting enzyme in beta oxidation