Exam 2 Flashcards
Glycolysis location
Cytosol
Glycogenolysis location
Cytosol
Glycogen synthesis location
Cytosol
Citric acid cycle location
Inside inner membrane of mitochondrial matrix
ETC location
Inner mitochondrial membrane
Oxidative phosphorylation location
Inner mitochondrial membrane
Pentose phosphate pathway location
Cytosol
Gluconeogenesis
Mitochondria and cytosol
FA oxidation location
Mitochondria and cytosol
Enzyme for Glucose –> Glucose-6-P
Hexokinase
Enzyme for G6P –> Fructose-6-P
Phosphoglucose isomerase
Bis vs Di
Bis is Phosphate on two different carbons, while bi is on the same carbon
What is an inositol?
6 carbon ring with 6 OH groups
Enzyme for F6P –> Fructose-1,6-Bisphosphate
Phosphofructokinase
Enzyme for Fructose-1,6-bisphosphate –> Dihydroxyacetone P or Glyceraldehyde-3-P and interconversion for DHP to G-3-P
Aldolase and Triose-P isomerase
Enzyme for G-3-P –> 1,3-BPG
Glyceraldehyde-3-P dehydrogenase
Enzyme for 1,3-BPG –> 3-P-Glycerate
Phosphoglycerate kinase
Enzyme for 3-P-Glycerate –> 2-P-Glycerate
P-Glycerate mutase
Enzyme for 2-P-Glycerate –> Phosphoenolpyrvuate
Enolase
Enzyme for Phosphoenolpyruvate –> Pyruvate
Pyruvate Kinase
Which enzymes in glycolysis are capable of interconversion and which reactions do they catalyze?
Phsophoglucose isomerase
Triose-P-Isomerase
Phosphoglycerate mutase
Enolase
Which enzymes use ATP to catalyze their reaction?
Hexokinase
Phosphofructokinase
Pyruvate kinase
Which enzymes use ADP to catalyze their reaction?
Phosphoglycerate kinase
Which enzymes convert NAD+Pi to NADH in their reaction
Glyceraldehyde-3-P dehydrogenase
Overall reaction of glycolysis with O2
Glucose –> 2 Pyruvate and 2 ATP
Overall reaction of glycolysis without O2
Glucose –> 2 Lactate
Overall reaction of Glycogenolysis
Glycogen(n) + Pi –> G-1-P + glycogen(n-1)
Overall reaction of Glycogen synthesis
Glycogen(n)+G-1-P+UTP –> Glycogen(n+1)+UDP+PPi
Overall reaction of citric acid cycle
Acetly-CoA –> 2CO2+8H+8e-
Overall reaction of ETC
8H+8e-+2O2 –> 4H2O+Energy
What are the 3 rate-limiting steps and their enzymes in glycolysis
1) Glucose –> G-6-P, Hexokinase
2) F-6-P –> F-1,6-Bis, Phosphofructokinase
3) Phosphoenolpyruvate –> Pyruvate, Pyruvate Kinase
What is Iodoacetate and how does it function?
A non-specific inhibitor of G-3-P dehydrogenase, preventing oxidation of NAD
How is NADH reoxidized back to NAD for use in Glycolysis?
In aerobic conditions:
- NADH -> shuttles -> ETC -> O2
In anaerobic conditions:
- NADH+pyruvate -> NAD+lactate (via lactate dehydrogenase)
Fate of pyruvate
Anaerobic conditions:
- Pyruvate+NADH -> lactate+NAD
- via Lactate dehydrogenase
Aerobic conditions:
- Pyruvate -> Acetyl-CoA -> TCA or FAs
- via pyruvate dehydrogenase
Fate of pyruvate in yeast
Pyruvate -> acetaldehyde
acetaldehyde -> EtOH
- via EtOH dehydrogenase and oxidation of NADH to NAD
Why does Glucokinase have a high Km?
Acts as glucose sensor. In liver, ensures that it only functions when hepatocyte glucose is elevated (meal). Also regulates insulin release from pancreatic ß-cells
Which reactions in glycolysis consume ATP?
Glucose to G6P
F6P to F6BisP
Why is anaerobic glycolysis important?
Allows for the production of ATP in cells that lack mitochondria (RBC and parts of eye) or cells in hypoxia
2 ways Glucose is transported into the cell
1) Facilitate diffusion
2) Countertransport with Na+
What type of transporters are used in facilitated diffusion of glucose?
Tissue-specific GLUT1-14 uniporters
What type of transporters are used in counter transport of glucose and what creates the gradient?
- SGLT transporters found in the intestinal epithelium
- Na+ gradient out of the cell created by Na+/K+ ATPase
GLUT for liver
GLUT-2
GLUT for brain
GLUT-1
GLUT for muscle and adipose tissue
GLUT-4, requires insulin
Fructose-1,6-Bisphosphatase: function and importance?
