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Flashcards in Exam 2 -- questions Deck (34):
1

where does heme synthesis occur

partly in mitochondria, partly in cytosol of liver and bone marrow

2

where does fa degradation occur

cytosol-->mitochondria

3

where does gluconeogenesis occur

first part in mitochondria, then in cytosol. (last step only possible in liver)

4

where does PPP occur

liver, adrenal cortex, lactating tissues, RBCs

5

PTL vs LPL vs HSL

PTL: dietary TG to MAG and glycerol
LPL: TGs in CMs to MAG and glycerol for adipocyte take up
HSL: hydrolyzes adipocyte TG to free fa's

6

CM vs VLDL vs LDL vs HDL

CM: dietary TGs in small intestine-->tissues
VLDL: endogenous TGs in liver --> tissues
LDL: made from depleted CM/VLDL, goes to tissues, only one that enters cells (receptor mediated endocytosis)
HDL: returns tissue chol to liver for degradation

7

how are odd chain fa broken down?

propionyl CoA (3C) --> succinyl CoA. uses cofactors biotin and B12. Uses ATP.

8

how much energy is obtained in ONE round of beta-oxidation?

make 1 FAD --> 2 ATP
make 1 NAD --> 3 ATP
make 1 ACoA --> 12 ATP
lose 2 ATP in making acyl-CoA
total= 15 ATP

9

what are the lipogenic enzymes:

1. ACoA carboxylase
2. fa synthesis
3. citrate lyase
4. malic enzyme
5. dehydrogenase in PPP

10

how/where does fa chain elongation occur?

-ER membrane
-acyl-Coa donates 2C units to carboxy terminus of malonyl CoA

11

how/where are double bonds added into fa's?

-ER membrane
-accomplished by desaturases (9, 6, 5)

12

sphingolipid synthesis pathway

All derived from sphingosine.
Sphingosine
(+fa) = ceramide
(+phosphotidyl choline) = sphingomyelin

OR ceramide + carb = glycosphingolipid

(Kaiser 5)

13

cellular control of chol synthesis?

inc chol activates protease, protease releases SREBP from ER, goes to nucleus to activate SRE. SRE now activates HMGCoa and LDL receptor production

14

KB synthesis pathway

2 ACoA --> acetoacetyl CoA -->3-hydroxy-3-methyl-glutaryl CoA -->acetoacetate-->acetone or 3-hydroxybutyrate

15

leptin vs ghrelin

leptin: produced by adipocytes, dec appetite, inc caloric expenditure
ghrelin: produced by stomach, inc appetite

16

10 essential aa's

PVT TIM HALL
phe, val, thr, trp, ile, met, his, arg, lys, leu

17

negative vs positive N balance

Positive : taking in more than you're excreting, growing/healing etc

18

CPS I vs CPS II

Both make CP
CPS I in mito during urea cycle
CPS II in cytosol during pyrimidine synthesis

19

how does NH4 get transported into bloodstream/liver for degradation?

1. most is glutamine
2. from muscles as alanine (pyr + NH3)

20

which are the 2 ONLY ketogenic aa's

Leu and Lys

21

how is THF made

folate to dihydrofolate to THF. Both steps need DHFR (dihydrofolate reductase). This is what methotrexate blocks!

22

how are dNTPs made from NTPs? ie how to make deoxyribose nt's from ribose nt's?

ribonucleotide reductase. Blocked by binding of dATP (adenosine deaminase deficiency)

23

Complex carb: proteoglycan. where is it made

protein w long repeating dissacharide units (GAG)
"slippery," has shell of water
made in golgi
form ECM, or found in synovial fluid, eye, cartilage, mucous

24

complex carb: glycoprotein. where is it made

protein with shorter oligosaccharide, usually branched
made in RER and golgi
found in ECM, cell surface, functions for cell recognition, antigenicity, globular proteins of human plasma

25

direct reversal of DNA damage

photolyase- e coli / plants. undoes uv damage

and

AGT (or MGMT)- not in plants, directly removes methyl group that was the mutation

26

MMR

identify methylated (older/parental) strand and fix errors on daughter strand according to old

27

BER

repairs base alteration or loss. glcosylase recognizes/removes error leaving AP site. Filled in by AP-endonuclease

28

NER. what are diseases assoc?

UV specific endonuclease, recognizes thymine dimers and cuts it out via "double incisions".
**XP, Cockayne's, Trichothiodystrophy

29

HR (also called recombination repair). what disease is assoc w this?

used to repair ds breaks.dna repaired from undamaged sister xsome. strands joined via holliday junction, branch migration and resolution.
**BRCA

30

Nonhomologous end-joining (NHEJ)

used to repair ds breaks. dna ends processed and ligase joins the 4 ends, more error prone, some dna lost

31

catecholamine synthesis pathway? what deactivates these/or inactivates the deactivation (drug)?

tyr-->dopa-->dopamine-->norepi-->epi. MAO inactivates, MAO inhibitor will increase life of NT

32

serotonin synthesis

try-->5-hydroxytryptophan-->serotonin.

33

define heritability

proportion of observable diff in trait bw individuals within population due to genetic differences

34

allelic vs locus heterogeneity

allelic: different mutations at some locus/gene cause disease
locus: multiple genes w mutations lead to "same" disease