Biochem REVIEW Flashcards
GLUT 2
Present in hepatocytes and pancreatic cells
GLUT 4
Present in adipose tissue and muscle
Glycolysis and intermediates
- Glucose
* Hexokinase - Glucose 6P
* Isomerase - Fructose 6P
* PFK-1 - Fructose 1,6-bisP
* aldolase - Glyceraldehyde 3P and DihydroxyacetoneP (converts to glyceraldehyde 3P with isomerase)
* Glyceraldehyde 3P dehydrogenase - 1,3-bisphosphoglycerate
* Phosphoglycerate kinase - 3Phosphoglycerate
* Mutase - 2 Phosphoglycerate
* Enolase - Phosphoenolpyruvate
* Pyruvate kinase - Pyruvate
Which step involves NAD+/NADH in glycolysis?
Glyceraldehyde 3P to 1,3 bisphosphoglycerate with the addition of inorganic phosphate and the glyceraldehyde 3P dehydrogenase enzyme
Where does glycolysis take place?
The cytoplasm
Lactic acid fermentation
Pyruvate and NADH to lactate and NAD+ using lactate dehydrogenase enzyme
Irreversible enzymes in glycolysis
Hexokinase, PFK-1, Pyruvate kinase
Two main outcomes of Acetyl-CoA
CO2+H2O via the citric acid cycle or fatty acids via fatty acid synthesis
What activates glycogen phosphorylase?
Glucagon from the liver, epinephrine from the liver and muscle, and AMP from muscle
What activates glycogen synthase?
Insulin from the liver and muscle
Glycogenolysis and Glycogenesis Cycle
Glucose1P to UDP glucose to glycogen back to glucose1P
Linear chain bonds in glycogen
Alpha 1,4
Branched bonds in glycogen
Alpha 1,6
Steps and enzymes that need different enzymes from glycolysis in gluconeogenesis
1) pyruvate to phosphoenolpyruvate - done with pyruvate carboxylase to oxaloacetate (in mitochondria) then PEP carbyoxykinase to get to phosphoenolpyruvate (in cytoplasm)
2) fructose1,6bisphosphate to fructose 6phosphate - done with fructose 1,6 bisphosphotase
3) glucose6phosphate to glucose - done with glucose 6 phosphotase
What is ribose 5 - phosphate necessary for and how do we get it?
Nucleotide synthesis and pentose phosphate pathway
Where does the pentose phosphate pathway occur?
Cytoplasm
Important enzyme in pentose phosphate pathway
Glucose 6P dehydrogenase
Pentose phosphate pathway intermediates
1) Glucose
2) Glucose 6P + NADP+
* glucose 6P dehydrogenase
3) 6-phosphogluconate + NADPH + NADP+
4) Ribulose 5P + CO2 + NADPH
5) Ribose 5P
NADPH function
Electron donor primarily in biosynthesis
Citric Acid Cycle
1) Acetyl CoA+Oxaloacetate
* citrate synthase
2) Citrate
* cis-Aconitase
3) Isocitrate
* isocitrate dehydrogenase
4) alpha-ketoglutarate
* alpha-ketoglutarate dehydrogenase
5) Succinyl-CoA
* succinyl-CoA synthetase
6) Succinate
* succinate dehydrogenase
7) fumarate
* fumarase
8) malate
* malate dehydrogenase
9) oxaloacetate
Energy from CAC
1 NADH from pyruvate dehydrogenase complex and 3 NADH from cycle, 1FADH2, and 1 GTP
Energy from glycolysis
2 NADH and 2 ATP
ATP from NADH
About 2.5 per
ATP from FADH2
About 1.5 per
How is the citric acid cycle inhibited?
ATP, NADH, some steps by succinyl coA or citrate
Where does the citric acid cycle take place?
The mitochondrial matrix
Complex I aka
NADH CoQ oxidoreductase
Complex I function
Transfer of electrons from NADH to coenzyme Q, four protons moved into intermembrane space
Coenzyme Q aka
Ubiquinone
Complex II aka
Succinate coQ oxidreductase
Complex II function
Transfers electrons from succinate to coenzyme Q using FADH2 intermediate, no proton pumping
Complex III aka
CoQH2-cytochrome c oxidoreductase
Complex III function
Transfers electrons from coenzyme Q to cytochrome c, 4 electrons pumped to inter membrane space
Complex IV aka
Cytochrome c oxidase
Complex IV function
Transfers electrons from cytochrome c to oxygen, 2 protons moved across membrane
