Heme

Question 1

how does heme synthesis start

Answer 1

ALA synthase is activated, synthesizes ALA from succinyl - CoA and glycine.

Question 2

where is ALA synthase located

Answer 2

mitochondria

Question 3

what happens to ALA after its made

Answer 3

gots to cytosol, where it turns into PBG from PBG synthase

Question 4

what happens to PBG after it’s made

Answer 4

jointed to form uroporphyrinogen by uroporphyirogen synthase III

Question 5

what is the committed step of heme synthesis

Answer 5

ALA synthase

Question 6

what inhibits heme synthesis

Answer 6

heme

Question 7

how does synthesis of p450 enzymes affect heme

Answer 7

consumes it and increases synthesis

Question 8

in general what do problems in synthesis of heme lead to

Answer 8

incrase in ALA synthase activity

Question 9

porphyrias

Answer 9

diseases of heme synthesis

Question 10

what causes AIP

Answer 10

deficiency of porphobiliinogen deaminase

Question 11

symptoms of AIP

Answer 11

urine gets a dark red color
confusion
sharp abodminal pain

Question 12

what is PCT caused by

Answer 12

deficiency of uroporphyrinogen decarbosylase

Question 13

symptoms of PCT

Answer 13

urine that emits pink gluorence under UV

photosensitivity of skin

Question 14

what does lead inhibit

Answer 14

porphobilnogen synthase and ferrochelatase

Question 15

symptoms of lead poisiong

Answer 15

simliar to porphyrias, prescne of lead adn heme precuros in urin

Question 16

what is the half-life of RBCs

Answer 16

120 days

Question 17

is bilirubin hydrophilic or hydrophobic

Answer 17

hydrophobic

Question 18

where is bilirubin produced

Answer 18

spleen

Question 19

how does bilirubin get to liber

Answer 19

binds to albumin

Question 20

how is conjugated bilirubin secreted?

Answer 20

hepatocytes into bilirary capillaried and through gall duct

Question 21

what is the compound that makes poo brown

Answer 21

urobilin

Question 22

how do you get urobilin

Answer 22

spontaneous oxidation of urobilinogen

Question 23

where does yellow color of urine come from

Answer 23

urobilins that were reabsorbed from gut

Question 24

under normal conditions should you see bilirubin in the urine

Answer 24

no

Question 25

is urobilin water solube?

Answer 25

yes

Question 26

hyperbilirubinemia

Answer 26

serum bilirumb >1.5 mg/dL

Question 27

kernitcterus

Answer 27

unconjuaged bilirubin crosses BBB and damages brain

Question 28

what causes prehepatic jaundice

Answer 28

destruction of RBCs causes excess serum bilirubin that the liver can’t deal with.

Question 29

in prehepatic jaundice what type of bilirubin is in the serum

Answer 29

unconjugated

Question 30

example of prehepatic jaundice

Answer 30

neonatal physiological juandice

hemolytic disease

Question 31

symptoms of hepatocellular jaundice

Answer 31

pale feces and urine

Question 32

in hepatocellular jaundice waht type of bilirubin is in serum

Answer 32

unconjugated

Question 33

what casues hepatocellular jaundice

Answer 33

hepatitis, or acetaminophen poising

Question 34

symptoms of cholestatic jaundice (obstruction)

Answer 34

pale feces

intense urine

Question 35

what type of bilirubin in tissues and urine in choelstatic jaundice

Answer 35

conjugated

Question 36

when do you see markers of ALT and AST

Answer 36

hepatocellular jaundice

Question 37

what is in the urine in hemolytic jaundice

Answer 37

no bilirunbin