Pentose Phosphate
This word is used to describe the first half of the pathway.
What is oxidative? (irreversible)
This is where glycogen is primarily stored and readily available when exercising.
What are muscles?
The formation of this intermediate by glucose-1-phosphate and UTP forms one half of the glycogen primer.
What is UDP-glucose?
This hormone is responsible for moving glucose out of the blood to form glycogen macromolecules.
What is insulin?
(Think: insulin lowers blood sugar...glucagon raises blood sugar)
This word is used to describe the second half of the pathway.
What is non-oxidative? (reversible)
Formation of UDP-glucose can be described in this way (favorable or unfavorable).
What is unfavorable?
(What is necessary to make it favorable?)
This enzyme is responsible for UDP-glucose formation.
What is UDP-glucose pyrophosphorylase?
Products of the pentose phosphate pathway include carbon dioxide, NADPH, and this 5-carbon molecule used in nucleic acid synthesis.
What is ribose-5-phosphate?
This end of glycogen is where more glucose monomers are added.
What is the non-reducing end?
This enzyme is responsible for forming branches in glycogen by cleaving 7-monomer units and adding it further back on the chain.
What is 4:6 transferase?
(Why name it 4:6? Think of the types of glycosidic bonds and which carbons they are formed between).
High levels of glucose 6-Phosphate will do this to glycogenesis?
Drive it forward.
This enzyme transfers two carbons between molecules.
What is transketolase?
(TranSKEtolase -> skiis come in pairs -> 2 carbons transferred. Good way to remember and distinguish this from transaldolase!)
This is the tyrosine-containing protein that binds with UDP-glucose to form the glycogen primer.
What is glycogenin?
This enzyme converts glucose 6-phosphate to glucose 1-phosphate.
What is phosphoglucomutase?
(Think back to Week 4's discussion on enzyme classes... what is the difference between a mutase and a transferase?)
High levels of ATP are expected to do this to glycogenesis.
What is up-regulate regulate glycogenesis?
A transfer of 2 carbons to erythrose 4-phosphate from another intermediate yields this six-carbon molecule.
What is fructose 6-phosphate?
This is the amount of energy stored in a diphosphate molecule, the same amount released when hydrolyzed.
What is -33.5 kJ/mol?
What's important here is not so much the amount of energy, but the fact that it has a negative deltaG. This means it is exergonic, and this is why, when coupled with UDP-glucose formation (no change in Gibbs free energy), the reaction is driven forward.
This enzyme continues adding UDP-glucose monomers to glycogen via alpha (1->4) glycosidic bonds.
What is glycogen synthase?
Protein phosphatases dephosphorylate glycogen synthase, thus affecting glycogen synthesis in this manner?
What is up-regulate?