Random high yield things from Bessesen lectures Flashcards
In what way is gluconeogenesis different from glycolysis?
- It runs in reverse
- Goes from pyruvate –> oxaloacetate –> PEP instead of straight backwards
Kids who can’t burn fat via TCA cycle present as what?
Hyperglycemia
What tissue is most important source of glucose in blood?
Liver & Kidney because have G6P-ase (enzyme). Liver > Kidney
What pathway level is responsible for a diabetic increased glucose level?
Gluconeogenesis
What is the source of the carbons that make the glucose that is in a fasting diabetic’s blood?
Lactate from RBCs
If a baby can’t sleep through the night, what is happening?
He is fasting and gets a neurologic problem. Depends upon his liver to produce glucose for his brain.
Tissues and glycogen
Muscle - its own use
Liver - whole body
Where does the glycogen pathway start and end?
Starts at glycogen
Ends at glucose-6-P (which goes on to glucose)
Explain coordinate regulation of glycogen
You are either going to make glycogen or break it down, you won’t do both together
UDP is a ___ form of glucose
high energy
What is function of branched structure of glycogen
- Rapid mobilization to glucose
2. Rapid storage as glycogen
What serves as a protein anchor to start glycogen chain?
Glycogenin
Which enzymes are critical for glycogen formation?
Glycogen synthase; only gives linear 1-4 structure. You need a branching enzyme (4:6 transferase) that counts 5 glucoses in to make a 1-6 bond for the branch.
Contrast the functions of glycogen in the liver vs. muscle
- Liver -> has glucose-6-phosphatase and can therefore turn it into glucose for the blood. 400g, doesn’t last you very long
- Muscle - does not have the G6P enzyme, so it ends up using glycogen (via G6P input into glycolysis) for energy
Key steps of glycogen (forward and backward pathway)
- Forward to glycogen: Glycogen synthase from UDP-glucose –> Glycogen
Branching enzyme as well. - Backward to G6P: Glycogenphosphorylase for Glycogen –> Glucose 1-P
Debranching enzyme as well.