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Biochem Metabolism Intro
KYCOM Block 3
71
Biochemistry
Graduate
10/15/2012

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Term
what is the purpose of a metabolic map
Definition
shows big picture of meatbolic pathways, helps you visualize intermediates, helps you figure out what happens if you block a step
Term
what does catabolism mean
Definition
degredation or break down of complex molecules
Term
what are examples of what catabolism might break down
Definition
proteins, polysaccharides, lipids, CO2, NH3, H20
Term
what is anabolism
Definition
synthesis. reactions form complex products from simple precursors
Term
what is an example of a reaction of anabolism
Definition
glucose to glycogen
Term
what role does catabolism play in metabolism
Definition
captures energy from ATP, NADH, or NADPH via degregation of energy rich fuels, allows us to reduce complex molecules from storage or diet into useful building blocks for other compounds
Term
what does catabolism do to proteins
Definition
breaks them into amino acids
Term
what does catabolism do to carbohydrates
Definition
breaks them into monosaccharides
Term
what does catabolism do to fat
Definition
breaks it into fatty acids and glycerol
Term
once catabolism makes amino acids, monosaccharides, fatty acids, and glycerol, in general, what happens to them
Definition
they are converted to acetylyl CoA, put into the TCA cycle which oxidizes it, and makes fatty acids, cholesterol, ketones, and other complex molecules
Term
what does anabolism do to amino acids
Definition
makes proteins
Term
what does anabolism need to work
Definition
energy: ATP or reduced compounds (NADH or NADPH)
Term
what is the time span of the well fed state
Definition
2-4 hours after eating
Term
what is another word for the well fed state
Definition
absorptive state
Term
what basic changes occur in the well fed state in the body
Definition
1. increase in blood glucose, AA, TAG (as chylomicrons) from the food
2. pancreas releases insulin secretion and decreases glucagon release
3. glycogen and TAG synthesis increases to replenish fuel storage
4. protein synthesis increased to replenish what was used in fasting (protein isnt stored)
Term
what factors control metabolism (control the enzymes)
Definition
avability of substrates, allosteric regulation, covalent modification, induction or repression of enzyme synthesis
Term
in what pathways of metabolism does gene expression regulation occur
Definition
in ones that are only active in certian physiological conditions, influences enzyme avability not how well the enzyme works
Term
on what molecules does covalent modification of enzymes occur
Definition
-OH or SER, THR, or TYR
Term
at what point do allosteric enzymes usually regulate
Definition
rate limiting steps
Term
what organ is considered to be the nutrient distribution center for the metabolism
Definition
liver
Term
what does the venous drainage of the portal vein do for the nutrients in the body
Definition
it makes them all enter the liver first to be stored, rerouted, or metabolized
Term
in general, what is the function of the liver in metabolism
Definition
allow smoothing of broad fluxuations of nutrients. stores what you have too much of or breaks down molecules to get the nutrients you need more of
Term
what is the only organ that releases glucose
Definition
liver
Term
what can the liver do with glucose
Definition
release it when blood glucose is low, store it if it is high
Term
what type of insulin receptors does the liver have
Definition
GLUT 2 non-insulin sensitive
Term
what happens to glucose once it enters the liver cell
Definition
it is phosphorlyated by glucokinase
Term
what can the liver do with glycogen
Definition
increase glycogen synthesis to store sugars, glycolysis
Term
describe the carbohydrate metabolism of the liver when well fed
Definition
when glucose is taken it it causes glycogen synthesis, increases activity of hexos monophosphate pathway providing NADPH and NADH for FA synthesis, increases glycolysis, decreases glyconeogenesis
Term
describe the role of liver in fat metabolism when well fed
Definition
increases fatty acid synthesis, turns chylomicrons into fatty acids then TAG which are transported to adipose in VLDL
Term
describe the role of the liver in amino acid metabolism when well fed
Definition
increases amino acid degration sending amino acids to the blood, tissues, or to be deaminated, uses AA in the tCA cycle for fat synthesis, increase protein synthesis
Term
describe the role of the adipose tissue in well fed metabolism
Definition
increases glycolysis to give energy, makes glycerol and uses VLDL FA to make fat, stores FA brought by VLDL
Term
why does adipose have to make glycerol
Definition
because the glycerol brought with the FA it stores, from the VLDL from the liver cannot enter the cell so to store TAG it needs to make its own glycerol to pair with the FA
Term
how does insulin inhibit TAG degredation
Definition
insulin causes phosphorlyzation of hormone sensitive lipase which inactivates it stopping TAG break down
Term
for what reason does muscle change its role in metabolism
Definition
changes in demand for ATP from muscle contraction
Term
what glucose receptors does adipose tissues have
Definition
GLUT 4 insulin sensitive
Term
what glucose receptors does skeletal muscle have
Definition
GLUT 4 insulin sensitive
Term
what role does the skeletal muscle have in carbohydrate metabolism when well fed
Definition
increases glucose transport due to increased blood glucose levels or insulin and does glycolysis with it, or increases glyogen synthesis
Term
what role does skeletal muscle play in amino acid metabolism when well fed
Definition
increases protein synthesis, increases uptake of branched chain AA to do protein synthesis
Term
what is the primary site for amino acid degredation
Definition
skeletal muscle
Term
how does heart muscle store glycogen or lipids
Definition
it doesnt
Term
does the heart need glucose storage? why
Definition
no, it is aerobic and needs oxygen at all times
Term
what does the heart muscle use for energy
Definition
fatty acids, glucose, ketone bodies
Term
for what reason does muscle change its role in metabolism
Definition
changes in demand for ATP from muscle contraction
Term
what glucose receptors does adipose tissues have
Definition
GLUT 4 insulin sensitive
Term
what glucose receptors does skeletal muscle have
Definition
GLUT 4 insulin sensitive
Term
what role does the skeletal muscle have in carbohydrate metabolism
Definition
increases glucose transport due to increased blood glucose levels or insulin and does glycolysis with it, or increases glyogen synthesis
Term
what role does skeletal muscle play in amino acid metabolism when well fed
Definition
increases protein synthesis, increases uptake of branched chain AA to do protein synthesis
Term
what is the primary site for amino acid degredation
Definition
skeletal muscle
Term
how does heart muscle store glycogen or lipids
Definition
it doesnt
Term
does the heart need glucose storage? why
Definition
no, it is aerobic and needs oxygen at all times
Term
what does the heart muscle use for energy
Definition
fatty acids, glucose, ketone bodies
Term
why does the brain need to use only glucose for fuel
Definition
FA cannot get across blood brain barrier
Term
when does the fasting state occur
Definition
approx 4 hrs after meal
Term
what type of reactions occur in the fasting state
Definition
catablic
Term
what is the first thing to happen when fasting that triggers the other fasting processes
Definition
blood glucose, AA, and TAG fall
Term
what does the pancreas do in response to low blood glycose, AA, or TAG
Definition
decreases insulin release, increases glucagon synthesis
Term
when fasting, what are the two main concerns the body has before all other
Definition
maintain blood glucose level for tissues (especially RBC and brain), mobilize FA and ketone
Term
what are the types of stored fuel in the body, how much energy can they provide relative to eachother
Definition
glycogen (provides little energy), protein (provides medium energy), TAG (provides most energy)
Term
how much protein can be lost in fasting before there are fatal complications
Definition
1/3
Term
what is the main function of the liver in fastin
Definition
maintain glucose levels
Term
how is the liver involved in carbohydrate metabolism when fasting
Definition
degrades glycogen into glucose, once glycogen depletes it does gluconeogenesis
Term
how is the liver involved in fat metabolism when fasting
Definition
it takes the products of fatty acid oxidation and uses them for gluconeogenesis. it takes in ketones and does ketoneogenesis
Term
what is the role of adipose in carbohydrate metabolism when fasting
Definition
decreased insulin causes endocytosis of GLUT 4 insulin sensitive receptors, this decreases enterance of glucose and decreases glycolysis
Term
what role does adipose tissue have in fat metabolism in fasting
Definition
degrades TAG for fuel. releases FA for fuel and glycerol to be used in gluconeogenesis in the liver, decreases FA uptake
Term
what role does skeletal muscle have in carbohydrate metabolism when fasting
Definition
decreased insulin causes endocytosis of GLUT 4 insulin sensitive receptors, this decreases enterance of glucose and decreases glycolysis
Term
what role does skeletal muscle have in lipid metabolism when fasting, what changes occur over time
Definition
uses ketone bodies and FA as fuel, at 2 weeks it uses FA almost exclusivly
Term
whty does the skeletal muscle change to only using FA when fasting
Definition
because they brain needs the ketone bodies
Term
what is the role of skeletal muscle in protein metabolism during fasting
Definition
breas down providing protein for gluconeogensis
Term
in the first few days of fasting what does the brain use as food
Definition
glucose only
Term
after prolonged fasting what does the brain use for food, why
Definition
mostly keytone bodies to conserve muscle protein
Term
what is the role of kidney in metabolism
Definition
can make or release glucose, metabolizes glutamein reasing ammonia which picks up H+ put into blood by ketone bodies (ketoacidosis), ammonia pickes up the acid and is excreted in urine
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