Absorptive State

when does the absorptive state occur

within 4 hours after meal

anabolism

predominate metabolism in absorptive state, (using energy and story it in bonds, building molecules)

insulins role in absorptive state

insulin promotes reactions of absorptive state (all reactions are happening because insulin is binding to its receptors increasing intracellular second messengers)

what happens to glucose in absorptive state

glucose is used to make ATP in glycolysis and stored as glycogen and gat

what happens to amino acids

amino acids used to make proteins, deaminated to use in Krebs cycle and stored as fat

what happens to fats

stored in adipose tissue

process of deamination

amino group removed from amino acid, turned into amonia, and liver turns amonia to urea

what happens to glucose when it enters the liver

in the liver, glucose becomes a triglyceride (which leaves liver and goes to tissue), or glycogen (which stays)

what happens to triglycerides in the adipose tissue

they have to be turned to fatty acids to get into the tissue, then turned back into triglycerides. some are converted to monoglycerides before entering and stay as monoglycerides

what happens to glucose in the adipose tissue

turns to triglycerides

what happens to glucose in almost all tissue

used for cellular respiration

what happens to glucose in muscle

becomes glycogen

what happens to amino acids in muscle

turn to proteins

what happens to amino acids in liver

MOST AA are not taken by the liver, but by other tissues for protein synthesis… although in liver they are turned to either urea, or to ketoacids which can make energy (for livers own needs!)

what happens to fructose and galactose in the liver

converted to glucose

which tissue is the major consumer of glucose

muscle burning most glucose, but brain is also an important consumer because it prefers a glucose substrate

why is glucose important in adipocytes?

they use glucose as energy in the absorptive state

what breaks down triglycerides before entering the adipose tissue

lipase

what happens to all extra glucose and amino acid

turns to fats

where is insulin produced

endocrine pancreas

insulin

hormone produced from the endocrine pancreas during the absorptive or fed state

where are beta cells in pancreas and what do they do

endocrine cells are organized into islets, beta cells release insulin from within the islets

what happens in muscle when plasma insulin is high

increase glucose uptake and utilization, net synthesis of glycogen and protein, and net amino acid uptake

what happens in adipocytes with increased plasma insulin

increase glucose uptake and utilization, net triglyceride synthesis

what happens in liver with increased plasma insulin

increase glucose uptake (liver doesn’t utilize), net glycogen, triglyceride synthesis, no ketone synthesis.

what increases insulin secretion

increase plasma glucose, increase plasma AA, glucose dependent insulino-tropic peptide (GIP) and parasympathetic activity

what decreases insulin secretion

sympathetic activity (plasma epinephrine)

how does diabetes cause hyperglycemia

without insulin, insulin targets cannot transport glucose into the cells, and so it builds up in the blood. . .

does brain need insulin to use glucose

NO

type 1 diabetes

insulin dependent; this is an autoimmune condition in which the immune system attacks the pancreas (beta cells can’t make insulin)

type 2 diabetes

insulin independent; these patients make insulin but have reduced response = insulin resistance (not from down-regulation, but maybe from less second messenger)