Ackerman Lectures 1 and 2 Flashcards Preview

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Flashcards in Ackerman Lectures 1 and 2 Deck (56):
1

aldo-sugars

D-glyceraldehyde (3), erythrose (4), ribose (5), glucose (6), mannose (6), galactose (6)

2

keto-sugars

dihydroxyacetone (3), ribulose (5), xylulose (5), fructose (6)

3

linear to cyclic isoform

addition of alcohol C to carbonyl C

4

hemi-acetal anomeric carbon

glucose; C1

5

hemi-ketal anomeric carbon

fructose; C2

6

glucose and galactose difference

C4; OH down and up, respectively

7

sucrose

glucose + fructose

8

lactose

galactose + glucose

9

maltose

glucose + glucose

10

reducing sugars

glucose, galactose, fructose, maltose, lactose--NOT sucrose (b/c link is at both anomeric Cs)

11

starch and glycogen vs cellulose

alpha vs beta 1,4 linkages, respectively

12

GLUT-1

in RBC, brain, kidney; glucose uptake

13

GLUT-2

liver, panc b-cell, intestinal contraluminal memb; rapid uptake/rel of glucose, high capacity, low affin; essential to liver fxn

14

GLUT-3

brain, kidney; glucose uptake

15

GLUT-4

skel musc, heart, adipose; insulin-stim glucose uptake; E storage

16

GLUT-5

SI; fructose, glucose absorp

17

glycolytic stages

hexose; splitting; triose

18

hexose stage

glucose-->F16BP; 2 mol ATP consumed per glucose; hexokinase, p-hexose isomerase, PFK-1

19

splitting stage

cleave F16BP-->1 aldo and 1 keto-sugar; keto isomerized to aldo; aldolase, triose-P-isomerase

20

triose stage

3C aldo sugar-->3C acid (pyruvate); 2 ATP prod per 3C intermed via subst-level phos; GA3PDH, PG kinase, PG mutase, enolase, pyruvate kinase

21

hexokinase

Pi transfer from ATP to glucose; low Km; traps glc in cell; -4 kcal/mol

22

p-hexose isomerase

converts aldo sugar to keto form (G6P-->F6P); +0.5kcal/mol

23

PFK-1

P transfer from ATP to F6P; E from hydrol 2ATP conserved in F16BP; -3.4kcal/mol

24

aldolase

splits F16BP into GA3P (ald) and DHAP (ket); fwd despite +5.7kcal/mol; pulled by exergonic rxns of triose

25

triose-P-isomerase

inter-converts GA3P with DHAP; KEY STEP b/c only ald can proceed; w/o, no net ATP yield; +1.8kcal/mol

26

GA3PDH

phos GA3P to 1,3BPG; includes oxid of ald to acid; NAD+ is e- acceptor here; +1.5kcal/mol

27

phosphoglycerate kinase

P trans from C-1 of 1,3BPG to ADP to form ATP; leaves 3-PGA intermed; first anaerobic ATP synth step; -4.4 kcal/mol

28

PGA mutase

reversible P position shift; +1.1 kcal/mol

29

enolase

non-hydrol cleavage (lyase) splits out H2O to create high-E phosphoenol intermed; -0.8 kcal/mol

30

pyruvate kinase

hydrol enol-P and transfers P to ADP-->ATP; leaves pyruvate; 2nd anaerobic ATP synth step; -7.5 kcal/mol

31

for every glucose that enters...

steps 1-5 occur once (6-CHO to two 3-CHO); steps 6-10 occur twice (two 3-CHO to two Pyr)

32

input

glc + 2ATP + 2NAD+ + 2Pi + 4ADP

33

output

2 Pyr + 2ADP + 2NADH + 2H+ + 4ATP + 2H2O

34

net rxn

glc + 2NAD+ + 2Pi + 2ADP --> 2Pyr + 2NADH + 2H+ + 2ATP + 2H2O

35

2,3-BPG

from 1,3-BPG mutase; cleaved by phosphatase-->2-PGA that feeds into glycolysis at enolase rxn

36

molecs phos by hexokinase using ATP as P donor

glucose, fructose, mannose

37

type I galactosemia

GALT deficiency; classic (t change UDP-glucose to UDP-galactose)

38

type II galactosemia

GALK deficiency (can't change galactose to galactose-1P)

39

type III galactosemia

GALE deficiency (can't interconvert UDP-glc and UDP-galac)

40

hypoglycemia

inhibition of phosphoglucomutase

41

pentose phosphate pathway, oxid branch

alt path of G6P metab; gen NADPH and ribulose 5-P

42

nonoxid PPP

ops as shunt if pentose-5-P levels sufficient in cell; for every 18C used to prod NADPH, 3 lost as CO2 and 15C captured as intermeds for glycolysis

43

glucose-6-phosphate dehydrogenase

G6P-->6-phosphoglucolactone; NADP+ to NADPH + H+

44

lactonase

add H2O; 6-phosphoglucolactone-->6-phosphogluconate

45

6-phosphogluconate dehydrogenase

6-phosphogluconate-->ribulose 5P; NADP+ to NADPH and H+; release CO2 (decarboxylation)

46

ribulose 5P

used by all cells to make phosphoribosylpyrophosphate (PRPP)

47

G6PDH inhibition

high intracellular [NADPH]

48

pentose phosphate shunt

sugar rearr to convert excess pentose-5-P into glycolytic intermeds; involve ketose donor, aldose acceptor; 2 enz's are link back to glycolysis (transketolase, transaldoslase); need 2 xylulose and 1 ribose 5P

49

transketolase

catalyzes 2-C transfers (TPP (vit B1) enz)

50

transaldolase

catalyzes 3-C transfers

51

G6PDH and pyruvate kinase deficiency

non-spherocytic hemolytic anemias

52

defective PK

ATP deficiency in RBCs

53

defective G6PDH

NADPH defic, impairs RBC abil to neutralize intracell radicals via GSH

54

deficiency of NADPH or NADH

interferes w/heme fxn directly; jaundice, Heinz bodies in RBCs

55

defective RBC pyruvate kinase

dec flux thru glycolysis; higher 2,3-BPG levels, lower Hb affin for O2 such that reduc in RBC number compensated by inc efficency in O2 deliv to tissues

56

G6PD deficiency

X-linked; diff mutations in gene w/diff levels of enz activity assoc w/range of biochem and clin phenos; asymp for years until take drugs (antimalarial, sulfonamide, aspirin and NSAIDs)/ingest fava beans (need GSH); global dist sim to malaria; hemolytic anemia reduces blood O2 and parasites fail to thrive