biochem

Question 1

what does anorexigenic mean?

Answer 1

makes you want to eat less and be more active

Question 2

what does orexigenic mean/

Answer 2

makes you want to eat more and be less active

Question 3

what nucleus contains the anorexigenic and orexigenic neurons

Answer 3

arcuate nucleus

Question 4

how does leptin regulate storage of fat?

Answer 4

released with excess adipose to signal to decrease wt

it is an adipokine

Question 5

what pathway does leptin work through?

Answer 5

non-receptor tyrosine kinase (JAK/STAT)

Question 6

what does adiponectin do?

Answer 6

downregulates inflammatory response

works opposite leptin

Question 7

how does increased fat lead to inflammation

Answer 7

inc fat -> inc leptin

this leads to dec adiponectin and so less antiinflammatory protection

Question 8

What are the characteristics of homozygote leptin deficiency?

Answer 8

normal birthwt, but obese in childhood
severe hunger w/ being aggressive
tx with recombinant leptin therapy

Question 9

which hormones are anorexigenic?

Answer 9

leptin, insulin, amylin, PYY, CCK

Question 10

what hormones are orexigenic?

Answer 10

ghrelin

Question 11

what hormone does the pancreas release?

Answer 11

insulin

amylin

Question 12

what hormone does adipose release?

Answer 12

leptin

Question 13

what hormone does the ileum release?

Answer 13

PYY (down regulates ghrelin)

Question 14

what hormone does the stomach release?

Answer 14

ghrelin

Question 15

what hormone does the duodenum release?

Answer 15

CCK

Question 16

what are the actions of ghrelin?

Answer 16

released when baroreceptors sense the stomach is relaxing

stim. orexigenic neurons to release GH

Question 17

When is CCK released?

Answer 17

when AA or FA enter the duodenum thereby signaling the release of bile by the gall bladder, amylase by the pancreas and signals satiety

Question 18

what anorexigenic and orexigenic hormones are released from the hypothalamus?

Answer 18

anorexigenic: CART, alpha-MSH
orexigenic: NPY, AgRP

Question 19

What hormones work on NPY hormone?

Answer 19

ghrelin stim
PYY inhib
LEptin and insulin inhib

Question 20

what hormones work on alpha MSH hormone/

Answer 20

insulin and leptin stim

Question 21

what receptors do alpha MSH bind?

Answer 21

MCR3 and 4

Question 22

what receptors do AgRP bind?

Answer 22

MCR4 (antagonizes) and Y1R

Question 23

what is the strongest activator of glycolysis

Answer 23

F2,6BP

Question 24

what is the regulatory step of glycolysis

Answer 24

fructose 6-p to fructose 1,6 bp

regulated by phosphofructokinase-1

Question 25

what does phosphokinase-2 do?

Answer 25

convert F6p to F2,6BP

Question 26

what does fructose 2,6 bisphosphatase do

Answer 26

removes p from F2,6BP leaving F6p (down regulates gluconeogenesis)

Question 27

what signal lipoprotein lipase? what does it do?

Answer 27

insulni | it adds triacylglycerols to adipocytes for storage

Question 28

what signals hormone sensitive lipase? what does it do?

Answer 28

glucagon | releases FA from adipocytes which then binds to albumin for transport to muscles

Question 29

how does the FA get into the mitochondria? And what happens to it once it does

Answer 29

via acyl carnitine shuttle | once inside the FA is released to form acyl coa then goes to beta oxidation

Question 30

will insulin upregulate or downregulate HMG coa reductase to make cholesterol?

Answer 30

upregulate

Question 31

what is the rate limiting step for FA biosynthesis?

Answer 31

acetyl coa conversion to malonyl coa | via acetyl coa carboxylase

Question 32

does citrate signal high or low energy?

Answer 32

high energy

Question 33

does acetyl coa signal high or low energy

Answer 33

high energy

Question 34

how does the body get acetyl coa from mito to cytosol for FA biosynthesis?

Answer 34

using citrate shuttle

Question 35

what is the rate limiting step of beta oxidation?

Answer 35

when FA shuttled by carnitine acyl transferases

Question 36

What enzyme is used to form ketone bodies from hmg coa

Answer 36

hmg coa lyase

Question 37

what enzyme is used to form cholesterol from hmg coa

Answer 37

hmg coa reductase | turns it to mevalonate which is need to build cholesterol

Question 38

What is von gierke disease? what tissue is most affected

Answer 38

aka glycogen storage dz type 1 glucose 6 phosphatase deficiency onset in childhood liver is most affected

Question 39

what are the genetics of von gierke?

Answer 39

AR

Question 40

what are the symptoms of von gierke/

Answer 40

``` fast induced hypoglycemia seizures failure to grow hyperlipidemia hyperuricemia ```

Question 41

what is the effect of ribose 5p build up associated with von gierke

Answer 41

will drive production of purines leading to gout

Question 42

how does von gierke fasting glucose compare to normal?

Answer 42

peaks at meals like normal but plummets in between as they are unable to perform gluconeogenesis or glycogenolysis

Question 43

what is the dietary treatment for von gierke?

Answer 43

uncooked corn starch every 1-3 hrs

Question 44

why do von gierke pts have hyperlipidemia?

Answer 44

mobilizes lipids to create energy source

Question 45

what is the difference between von gierke type a and type b?

Answer 45

type a= inact of g6p | type b= inact of g6p transporter

Question 46

what is pompe disease? genetics?

Answer 46

lysosomal acid alpha glycosidase def. childhood onset AR, all tissues

Question 47

pathogenesis of pompe dz?

Answer 47

glycoen end up in lysosomes where acid alpha glycosidase breaks them down with def, glycogen builds up in lysosome and is not released

Question 48

what is cori dz? genetics?

Answer 48

amylo-1,6 glucosidase def AR effects liver heart and muscle

Question 49

what is the pathogenesis of cori?

Answer 49

effects glycogen breakdown in cytosol enzyme amylo-1,6 glucosidase debranches glycogen normally with def, glycogen use is limited as only the outer portion is able to be broken down

Question 50

what is McArdle? Genetics

Answer 50

myophosphorylase def AR, muscle childhood/adult onset

Question 51

pathogenesis of McArdle?

Answer 51

unable to breakdown muscle glycogen this leads to lack of muscle endurance intense exercise can lead to rhabdomyolysis