Usmle Step 1 Fa Biochemistry Metabolism

Front 1

Site of metabolism:
Fatty acid oxidation

Back 1

Mitochondria

Front 2

Site of metabolism: glycolysis

Back 2

Cytoplasm

Front 3

Site of metabolism: heme synthesis

Back 3

Mitchondria and cytoplasm

Front 4

Site of metabolism: fatty acid synthesis

Back 4

Cytoplasm

Front 5

Site of metabolism: acetyl CoA production

Back 5

Mitchondria

Front 6

Site of metabolism: HMP shunt

Back 6

Cytoplasm

Front 7

Site of metabolism: protein synthesis (RER)

Back 7

Cytoplasm

Front 8

Site of metabolism: urea cycle

Back 8

Both cytoplasm and mitchondria

Front 9

Site of metabolism: gluconeogenesis

Back 9

Cytoplasm and mitchondria

Front 10

Site of metabolism: steroid synthesis

Back 10

Cytoplasm

Front 11

Site of metabolism: TCA cycle

Back 11

Mitchondria

Front 12

Site of metabolism: oxidative phosphorylation

Back 12

Mitchondria

Front 13

Rate determining enzyme: glycolysis

Back 13

Phosphofruktokinase-1

Front 14

Rate determining enzyme: gluconeogenesis

Back 14

Fructose 1,6 bisphosphatase

Front 15

Rate determining enzyme: TCA cycle

Back 15

Isocitrate dehydrogenase

Front 16

Rate determining enzyme: glycogen synthesis

Back 16

Glycogen synthase

Front 17

Rate determining enzyme: glycogenolysis

Back 17

Glycogen phosphorylase

Front 18

Rate determining enzyme: HMP shunt

Back 18

G6PD

Front 19

Rate determining enzyme: de novo pyrimidine synthesis

Back 19

Carbamoyl phosphate synthetase II

Front 20

Rate determining enzyme: De novo purine synthesis

Back 20

Glutamine PRPP amidotransferase

Front 21

Rate determining enzyme: urea cycle

Back 21

Carbamoyl phosphate synthetase

Front 22

Rate determining enzyme: Fatty acid synthesis

Back 22

Acetyl CoA carboxylase (ACC)

Front 23

Rate determining enzyme: Fatty acid oxidation

Back 23

Carnitine acyltransferase I

Front 24

Rate determining enzyme: ketogenesis

Back 24

HMG COA synthase

Front 25

Rate determining enzyme: cholesterol synthesis

Back 25

HMG CoA reductase

Front 26

Amnt of ATP produced/glucose :
(1) malate aspartate shuttle (heart and liver)
(2) glycerol 3 phosphate shuttle (muscle)
(3) anaerobic glycolysis

Back 26

(1) malate aspartate shuttle (heart and liver): 32
(2) glycerol 3 phosphate shuttle (muscle): 30
(3) anaerobic glycolysis: 2 NET

Front 27

Hexokinase
(a) location in body
(b) affinity (Km)
(c) capacity (Vm)
(d) inducibility by insulin?
(e) feedback inhibition?

Back 27

(a) location in body: ubiquitous
(b) affinity (Km): high
(c) capacity: low
(d) inducibility by insulin? No
(e) yes (G6P)

Front 28

Glucokinase
(a) location in body
(b) affinity (Km)
(c) capacity (Vm)
(d) inducibility by insulin?
(e) feedback inhibition?

Back 28

(a) location in body: liver and beta cells of pancreas
(b) affinity (Km): low
(c) capacity (Vm): high
(d) inducibility by insulin?: yes
(e) no

Front 29

Rotenon, CN-, antimyinA, CO: oxidative phosphyrlation poison class and effect

Back 29

Directly inhibit electron transport, causing a decrease proton gradient and block ATP synthesis
(b)

Front 30

Oligomycin: oxidative phosphorylation poison class and effect

Back 30

Direclty inhibit mitochondrial ATPase causing an incr proton gradient. No ATP produced b/c electron transport stops

Front 31

2,4 DNP, aspirin, thermogenin brown fat: oxidative phosphylation poison class and effect

Back 31

Incr permeability of membrane ; causing a decr proton gradient and incr O2 consumption. ATP synth stops but electron transport continues

Front 32

Pyruvate decarboxylase
(a) location
(b) rxn catalyzed
(c) enzyme requirements

Back 32

(a) mitochondria
(b) pyruvate to oxaloacetate
(c) biotin, ATP, ATP

Front 33

PEP carboxykinase
(a) location
(b) rxn catalyzed
(c) enzyme requirement

Back 33

(a) cytosol
(b) oxaloacetate to phophoenolpyruvate
(c) requires GTP

Front 34

Fructose 1,6 BP
(a) location
(b) rxn catalyzed

Back 34

(a) cytosol
(b) fructose 1,6BP to frucose 6P

Front 35

Glucose 6 phosphatase
(a) location
(b) rxn catalyzed

Back 35

(a) in ER
(b) G6P to glucose

Front 36

Main purpose of HMP (pentose phosphate) shunt

Back 36

Produce NADPH

Front 37

Processes for which NADPH is required

Back 37

Fatty acid and steroid synthesis
Glutathione reduction inside RBC's

Front 38

Sites of HMP shunt

Back 38

Lactating mammary glands, liver, adrenal cortex, RBC's

Front 39

Key enzymes in HMP shunt (products of rxn)
(a) oxidative phase
(b) nonoxidative phase

Back 39

(a) irreversible; glucose 6 phosphate dehydrogenase (NADPH)
(b) transketolase (requires thiamine)-(ribose 5 phosphate, G3P, G6P)

Front 40

Essential AA's
(a) glucogenic only
(b) glucogenic/ketogenic
(c) ketogenic only

Back 40

(a) met, val, arg, his
(b) ile, phe, thr, trp
(c) leu, lys

Front 41

Derivatives of phenylalanine

Back 41

Tyrosine to dopa and thyroxine
Dopa to melanin and dopamine
Dopamine to NE
NE to epi

Front 42

Derivatives of tryptophan

Back 42

Niacin to NAD+/NADP+
Serotonin to melatonin

Front 43

Derivatives of histadine

Back 43

Histamine

Front 44

Derivatives of glycine

Back 44

Porphyrin (to heme)

Front 45

Derivatives of arginine

Back 45

Creatinine
Urea
Nitric oxide

Front 46

Derivatives of glutamate

Back 46

GABA
Glutathione

Front 47

Anabolic effects of insulin

Back 47

Increase glucose transport
Increase glycogen storage and synthesis
Increase triglyceride storage and synthesis
Increase Na+ retention in kidneys
Inc protein synthesis (muscles)
Incr cellular uptake of K+

Front 48

Location of Glut1

Back 48

RBC's
Brain

Front 49

Location of glut 2

Back 49

Beta islet cells
Liver
Kidney
NOTE: bidirectional

Front 50

Location of glut 4

Back 50

Adipose tissue
Skeletal muscle
NOTE: insulin responsive

Front 51

Fuel used during exercise
(1) first 100 s (sprint)
(2) minutes later (long run)
(3) hours (marathon)

Back 51

(1) first 100 s: stored ATP, creatine phosphate, anaerobic glycolysis
(2) minutes later (long run): above +oxidative phosphorylation
(3) hours (marathon): glycogen, FFA oxidation; glucose conserved for final sprint

Front 52

Fuel used during starvation and fasting: Day 1-3

Back 52

Priority to supply brain and RBC's
Blood glucose maintained by:
(1) hepatic glycogenolysis
(2) adipose release of GGA
(3) muscle and liver shifting fuel use from glucose to FFA

Front 53

Fuel used during starvation and fasting: after day 3

Back 53

Hepatic formation of ketone bodies (supply brain, heart)

Front 54

Fuel used during starvation and fasting: several weeks

Back 54

Keton bodies main source for brain and heart.
Survival time determined by amnt of fat stores.
After depleted, vital protein degradation accelerates (organ failure and death)

Front 55

Name the essential fatty acids

Back 55

Linoleic and linolenic acids
Arachidonic acid if linoleic acid is absent

Front 56

Major apolipoproteins and fct

Back 56

A-I: activates LCAT
B-100: Binds to LDLR,mediates VLDL secr
C-II: Co-factor for lipoprotein lipase
B-48: mediates chylomicron secretion
E: mediates extra (remnant) uptake