C: Cell biology Flashcards
Anabolic pathways
Synthesise complex molecules from precusors (a.a -> proteins)
- Uses ATP
Catabolic pathways
Oxidation of complex molecules to simple precursors (proteins ->a.a)
- Produces ATP
Types of allosteric effectors in controlling metabolism (2)
- Allosteric inhibitor (Distorts enzyme active site)
- Allosteric activator (Shapes enzyme active site
Reversible covalent modification (control of metabolism)
Covalent attachment that changes enzyme activity (ex. phosphorylation)
Kinase enzyme
phosphorylates target (Uses ATP)
Phophatase enzyme
Removes phosphate (release Pi)
Output of glycolysis
1 glucose = 2 net ATP, 2 NADH, 2 Pyruvate
Regulation of glycolysis (3)
- Hexokinase (inhibited by product glucose 6-phosphate)
- Phosphofructokinase 1 (inhibited by citrate, ATP, H+ and increased by AMP and ADP)
- Pyruvate kinase (Inhibited by ATP, increased by fructose 1,6 biphosphate)
Aerobic outcome of (2) pyruvate
2 acetyl CoAs
Anaerobic outcome of (2) pyruvate
2 lactate
What does NAD+/NADH carry?
H+ and 2e-
What does FAD/FADH2 carry?
2H+ and 2e-
Outcome of Citric Acid Cycle (TCA)
(1 Acetyl CoA, 2Co2 + 3NADH + FADH2 + GTP) x2
Regulation of citric acid cycle (3)
- Citrate (inhibited by NADH, succinyl-CoA, citrate, ATP; increased by ADP)
- Isocitrate dehydrogenase (inhibited by ATP, increased by Ca2+, ADP)
- A-Ketoglutarate dehydrogenase (inhibited by succinyl-CoA, NADH; increased by Ca2+)
Total yield of ETC (oxidative phosphorylation)
30-32 ATP
Triacylglycerol oxidation (Palmitate oxidation)
Free fatty acid -> B-oxidation -> 2 acetyl-CoAs, -2ATP, 7 NADH, 7FADH2, 8 Acetyl-CoAs
How many protons are pumped out in ETC to create 1 ATP molecule?
4 protons = 1 ATP
