PHYSL402 Lecture Notes - Lecture 5: Galactose, Neuropeptide, Blood Sugar

• School: University of Alberta
• Department: Physiology
• Course: PHYSL402
• Professor: Dr.shamza

Document Summary

Lecture 5: role of the liver and gut in glucose homeostasis (jan 13/16) Describe glycogen synthesis and breakdown pathways and their regulation. Glucose transporters and glucose sensors (in gastrointestinal tract) Glucose can be made de novo in liver from non-glucose substrates (ie aa) = gluconeogenesis. Substrate cycles involved in regulation of glucose production by the liver: glycolytic/gluconeogenic, glycogenic/glycogenolytic pathways. Low-affinity, high-capacity glucose transport protein contrasts with other isoforms with. (cid:373)eta(cid:271)oli(cid:272)ally (cid:862)traps(cid:863) glu(cid:272)ose as glu(cid:272)ose-6-p: liver also has hexokinase; main one = gk. Gk regulatory protein (gkrp): can shut off gk. Synthesis: udp glucose allows glucose to join on a primer chain (glycogen with n residues), facilitated by glycogen synthase. Breakdown: glycogen phosphorylase = responsible for rate limiting step (reg = next slide) Hormones like epinephrine and glucagon can regulate glycogenesis as a whole. Under stress, makes sense that want body to be filled with glucose.