Integrating Metabolism Flashcards
the liver is a very fexible organ that changes ________ expression to meet short and long term needs
enzyme
the fate of carbohydrates in the liver is dependent on
metabolic needs
what type of regulation is important to carbohydrate metabolism?
allosteric & hormonal
initial processing of CHOs yields
G-6-P
5 fates of G-6-P
- glucose processing
- glycogen
- glycolysis
- lipids
- PPP
what are the 4 fates of amino acids in the liver
- protein synthesis
- branched amino acids remain untouched
- synthesis of hormones nucleotides
- degradation
what are the 3 methods of degradation for amino acids in the liver?
- deamination
- transaminaton
- glucogenic/ketogenic
ketone bodies are formed from
AcCoAs
AcCoAs are used to make
cholesterol
what type of oxidation produces AcCoAs?
B-oxidation
what cells store lipids and FAs in the liver
ito cells
how are FAs and lipids transported?
by making them triglycerides that are then transported by VLDL or albumin
albumin transports up to 10 fatty acids
provide 2 reasons why adipose tissue is not as inactive as we think
- extensive glutamine metabolism
- hybernation
HSL plays a major role in
metabolism
how is HSL regulated
- inactivated by insulin
- activated by epinephrine & glucagon
w/ HSL what is the fate of glycerol?
taken back to glycolysis or gluconeogenesis
brown adipose tissue is high in
- MTCH content
- vascularization
what is the relation of brown adipose tissue in obese ppl?
decreased levels
non-shivering thermogenesis is reliant on what ETS uncoupling protein>
thermogenin
explain the function of thermogenin
- couples ATP synthesis to electron/proton movement to generate heat
explain how the muscle chooses to use different fuels according to work load
- resting: uses FA from adipose tissues and ketone bodies
- working: glucose, FA, ketone bodies
when a muscle’s maximal work load is reached what is the alternate ATP supply?
phosphocreatine
what production is favored when a muscle is at its maximal work load? what are the predominant cycles?
- favored: lactate production
- cycles: cori & anerobic glycolysis
what are the brains 2 primary fuels?
glucose & ketone bodies
what are the 2 major fuels of the body?
FA & carbohydrates
what are the storage forms of FAs and carbohydrates?
FAs: triglycerides
carbohydrates: glycogen
what are the 4 major hormone classes?
- peptides
- amines
- steroids
- elcosanoids
peptides are produced by the
hypothalamus & pituitary gland
act on pancreas to release insulin,glucagon.somatostatin
what are amines formed from? give some examples
formed from: tyrosine
ex: epinephrine, thyroid hormone
steroids are formed from? give some examples
formed from: cholesterol
ex: Vit.D calcitriol
elcosanoids are fromed from
20 carbon fatty acids
what are the regulation methods for hormone concentrations?
- secretion
- internalization
- degradation
what specific types of hormones have a rapid response? which have a slow-acting reponse? what are the reasons for this?
rapid: peptides, amines
slow-acting: thyroid, cortisol
reasons: mode of action & receptor location
list the Hierarchy of Hormonal Control
environment -> CNS -> hypothalamus -> pituitary -> secondary organs -> primary targets
what are the 2 organs of the endocrine network?
- hypothalamus
- adrenal medulla
what does the hypothalamus answer to?
the CNS
the adrenal medulla produces
epinephrine
the pituitary gland releases hormones to
secondary organs
what are the 5 hormones produced by the anterior pituitary gland that activate secondary organs?
- ACH
- TSH
- FSH
- LH
- GH
what are the 2 major functions of the pancreas
- exocrine: insulin & glucagon
- endocrine: aids in digestion
the pancreas produces peptide hormones by cells types. Which cells produce which hormones?
- a cells: glucagon
- B-cells: insulin
- S-cells: somatostatin
what 3 hormones play a major role in regulating glucose metabolism in the body?
- insulin: glucose needs to be used
- glucagon: glucose needs to be made/conserves
- epinephrine
the release of insulin is tightly regulated by
blood glucose
what 2 major metabolic activities are stimulated by insulin?
- glucose uptake/use
- FA synthesis/storage
list some activities that are increased w/ insulin
- glucose uptake
- glycolysis
- glycogenesis
- FA syn
- TG syn
which enzymes are increased w/ insulin
- glucokinase
- PFK-1
- PDH
- glycogen synthase
- AcCoA carboxylase
which activities are decreased by insulin?
glycogenolysis
which enzyme activities are decreased by insulin?
glycogen phosphorylase
what is released in response to low glucose concentrations
glucagon
list the 3 methods in which glucagon can help to increase blood glucose levels
- glycogen metabolism
- glucose metabolism
- FA metabolism
what are the metabolic effects of glucagon in the liver?
- glycogenolysis: I phosphorylase
- glycogenesis: D glycogen synthase
- glycolysis: D PFK-1
- gluconeogenesis: I F16BiP —- D PK
what is the effect of glucagon in adipose tissue?
fatty acid mobilization: I HSL
what are the physiological effects exhibited by epinephrine?
- I pluse rate
- I BP
- D dialation
increase O2 delivery to muscles
what are the metabolic effects exhibited by epinephrine?
- I [blood glucose]
- glucose metabolism
- FA metabolism
- hormonal signals
list 4 reasons why we can NOT survive 3 months w/o eating
- ketacedosis
- below 50% body protein
- dehydration
- osmolarity
how can the liver adapt to starvation?
- break down proteins for glucose
- use products from the TCA cycle to make glucose
- oxidizes FAs
- KB increases
what might be an adaptation in repose to calorie restricted diets and cancer?
cahexia
name the two serums that when decreased can induce apoptosis in cultured cells
FBS & BSA
what is the function of the liver
service organ
what are some major pathways of the liver?
- urea cycle
- bile salts syn
major substrates of the liver
- FA
- glucose
- lactate
- glycerol
- AAs
liver products
- glucose
- VLDL
- HDL
- urea
- uric acid
liver specialty enzymes
- glucokinase
- G-6-P
- glycerol kinase
- PEPCK
- arginase
- HMGCoA synthase
- HMGCoA lyase
brain function
coordinate events
brain major pathways
- glycolysis
- AA metabolism
brain substrates
- glucose
- AA
- ketone bodies
brain major product
lactate
heat function
circulation
heart major pathways
aerobic
heart substrates
- FAs
- lactate
- glucose
heart specialty enzymes
- lipoprotein lipase
- extensive electron transport chain
function of adipose tissue
store and release triglycerides
adipose tissue major pathways
- FA esterification
- triglycerides hydrolysis
adipose tissue major substrates
- glucose
- lipoproteins
adipose tissue major products
- FAs
- glycerol
adipose tissue specialty enzymes
- lipoprotein lipase
- hormone sensitive lipase
muscle function
motion
muscle major pathways
- glycolysis
- aerobic
muscle major substrates
- glucose
- ketone bodies
- FAs
muscle major products
lactate
muscle specialty enzymes
- lipoprotein lipase
- extensive electron transport system
kidneys function
excretion
makes glucose in extended starvation
kidneys major pathways
- gluconeogenesis
- arginine synthesis
kidneys major substrates
- FAs
- lactate
- glycerol
kidneys major products
glucose
kidneys specialty enzymes
PEPCK
RBCS function
oxygen transport
RBCs major pathways
- glycolysis
- PPP
RBCs major substrates
glucose
RBCs major products
lactate
RBCs specialty protein
hemoglobin
diabetes is a disease of
carbohydrate metabolism
what are the characteristics, causes, and treatments for type I diabetes?
characteristics: D B-cells, hyperglycemia, low insulin
treatments: insulin
causes: autoimmune destruction
what are the characteristics, causes, and treatments for type II diabetes?
characteristics: peripheral insulin resistance
causes: insulin insensitivity
treatment: excerise, diet
why is diabetes so dangerous?
advanced glycation endproducts: OH reacts w/ lipoproteins/liporeceptors causing extensive damage
what are the symptoms of type I diabetes?
polydypsia, polyuria
