Aerobic metabolism Flashcards
Where does gluconeogenesis occur?
Liver
What are major enzymes of cellular redox?
Flavin adenine dinucleotide and Nicotinamide adenin dinucleotide
How many H can FAD and NAD accept?
FAD accepts 2H, NAD accepts 1H
What stages are involved in aerobic respiration?
Pyruvate oxidation, TCA cycle, ETC
What is the reaction for pyruvate oxidation?
Pyruvate + O2 + NAD+ (pyruvate deydrogenase) –> CO2 + acetyl-CoA + NADH
How is the action of pyruvate dehydrogenase regulated?
By PDH complex. PDH kinase inactivates PDH by phosphorylation; PDH kinase active when ATP:ADP is high; PDH kinase inhibited by pyruvate. PDH phosphotase activates PDH by dephosphorylation; PDH phosphotase activated when Ca2+ high (muscular contraction)
What is net equation for Krebs?
Acetyl CoA + ADP + Pi + 3NAD+ + FAD +3H2O –> ATP + 3NADH + FADH2 + 2CO2
What is the “aim” of Krebs?
All C from original glucose formed in to CO2; traps high energy electrons in reduced coenzymes
What occurs during Krebs?
Oxaloacetate (4C) + acetyl-CoA –> citrate (6C) + CoA; citrate (6C) + NAD+ –> 5C molecule + CO2 + NADH; 5C molecule + NAD+ –> succinyl-CoA (4C) + CO2 + NADH; succinyl (4C) –> ATP + succinate (4C); succinate (4C) + NAD+ + FAD+ –> oxaloacetate (4C) + NADH + FADH2
What is the overall process that occurs in the ETC called?
Mitochondrial oxidative phosphorylation
What occurs within the ETC?
NADH and FADH2 are oxidised, releasing e-s; e-s flow along series of membrane proteins; redox reactions provide energy to actively transport H+ into intermembrane space; H+ gradient is generated, creating a proton motif force; H+ undergoes facilitated diffusion down chemiosmotic gradient through ATPase; proton flow causes rotary motor of ATPase to spin; mechanical energy of spinning motor is captured and combines ADP + Pi –> ATP; O2 + 4e- + 4H+ –> 2H2O
How many protons does NADH pump?
10
How many protons does FADH2 pump?
6
What complexes do NADH supply?
4H+ at complex I; 4H+ at complex III; 2H+ at complex IV
What complexes do FADH2 supply?
4H+ at complex II; 2H+ at complex IV
Where does oxygen act as final acceptor?
Complex IV (cytochrome C oxidase)
What number complex is ATPase?
Complex V
What is the absolute net ATP?
+30ATP
How many kcal does glucose contain?
720kcal/mol
How many kcal does ATP contain?
7.3kcal/mol
How many moles of ATP is harvested from 1mole ATP theoretically?
30 ATP per mole glucose
How many moles of ATP is harvested from 1mole ATP actually?
26 ATP per mole glucose
Why is actual efficiency of ATP production different to theoretical?
Inner membrane leaky to H+: human skeletal muscle ~70% efficient. H+ gradient is used for other purposes, such as facilitating pyruvate transport into mitochondrial matrix from cytoplasm
