Interconversions (complete) Flashcards
(29 cards)
What happens to glycogen in a fed state
Glucose-6-P is used to make glycogen
how many ATP and UTP are used per G6P added to glycogen
1 ATP
1 UTP
What happens to glycogen in a fasting state
glycogenolysis, glycogen is broken down to create G6P
where do products of glycogenolysis go in the liver
they are converted to glucose and sent out to the rest of the body
where do products of glycogenolysis go in muscle
it is used in the muscle to make ATP
What happens in terms of the amino acids serine and alanine in a fed state
they are made from glycolysis intermediates
What happens in terms of amino acids in a fasting state
they can be used to make more glucose
what is different about the glucogenic abilities of serine and alanine compared to other amino acids
those can enter directly into the gluconeogenesis pathway, the others need to be made into oxaloacetate first
What is the process of converting galactose into glucose
- Galactose is converted to galactose-1-phosphate by galactokinase
- galactose-1-phosphate get UMP (from the 4th step) and becomes UDP galactose
- UDP galactose in converted into UDP glucose
- UDP glucose gives off UMP and becomes glucose-1-phosphate
- glucose-1-phosphate is converted into glucose-6-phosphate by phosphoglucomutase
What things can glucose-6-phosphate become
- glucose (gluconeogenesis)
- glycogen (glycogenesis)
- Fatty acids (through acetyl-CoA
What is the process of converting fructose into glucose
- fructose is converted into fructose-1-phosphate by fructokinase
- fructose-1-phosphate is broken down into Dihydroxyacetone phosphate and glyceraldehyde by aldolase
- glyceraldehyde is phosphorylated into glyceraldehyde 3 phosphate
- Dihydroxyacetone phosphate and glyceraldehyde-3-phosphate are in the glycolytic pathway
Where does fructokinase primarily occur
in the liver
how are glycolysis products used in triacyglyceride synthesis
- glycerol is made from glycerol-3-phosphate
2. Actyl-CoA is used to make fatty acids
How do triacylglycerols participate in gluconeogenesis
the glycerol can be put into the gluconeogenesis pathway
acetyl-CoA can’t because running it through the krebs cycle gets rid of CO2, so no net gain of carbons that way
how is ribose-5-phosphate made from the glycolysis pathway
from glucose-6-phosphate by glucose-6-phosphate dehydrogenase
What are anapleurotic reactions
the conversion of precursor molecules into citrate cycle intermediates
What are anabolic reactions
citrate cycle intermediates are used as precursor molecules for other important molecules
Why are fatty acids not glucogenic
because the Acetyl-CoA must run through the krebs cycle to be sent back up the gluconeogeneic pathway, but 2 CO2 molecules leave, meaning there is no net gain of glucose carbons from acetyl-CoA
What is the precursor molecule to ketones
acetyl-CoA
Where are ketones formed
in the liver
what does insuiln do to the formation of ketones
inhibits it
what does glucagon do to the formation of ketones
stimulates it
what can ketones be used for
fuel
What are the three main ketones
acetone
acetoacetate
beta-hydroxybutyrate
