Porphyrins And Hemoglobin

Front 1

Porphyrin serve as prosthetic groups that fxn in:
O2 transport
Peroxidase breakdown
e- transport
hydroxylation
light absorption

Back 1

hemo and myoglobin
catalase
cytochromes A, B, C
cyto p450
chlorophyll

Front 2

chlorophyll and hemoglobin have which metal ions

Back 2

Mg and Fe

Front 3

First rxn in heme synthesis

Back 3

glycine + succinyl coA -----------> delta-aminoevulate + CO2+ coA in the presence of delta aminoevulate synthase

Front 4

what is used as a coenzyme for delta aminoevulate synthase

Back 4

pyridoxal phosphate

Front 5

2 things that exhibit feedback on delta eminoevulate synthase

Back 5

heme and heavy metal ions

Front 6

second reaction of heme synthesis

Back 6

2 molecules of delta aminoevulate condense to form porphobilinogen

Front 7

third reaction of heme synthesis

Back 7

4 molecules of porphobilinogen yield hydroxymethylbilane with loss of 4 ammonias

Front 8

fourth reaction of heme synthesis

Back 8

ring closure catalyzed by uroporphyrinogen synthase to yield uroporphyrinogen III

Front 9

which enzyme catalyzes final reaction in heme synthesis

Back 9

ferrochelatase

Front 10

what decreases heme synthesis

Back 10

increased heme or hemin

Front 11

globin synthesis is activated by what

Back 11

hemin which keeps synthesis of heme and globin in balance

Front 12

senescent red cells processed by what

Back 12

reticuloendothelial cells

Front 13

hemin, protoporphyrin, and albumin converted to bilirubin by

Back 13

hepatic parenchymal cells

Front 14

hyperbilirubinemia

Back 14

occurs when heme degradation exceeds bilirubin removal from liver

Front 15

prehepatic (hemolytic jaundice)

Back 15

acute and chronic hemolytic anemia

neonatal physiological jaundice

Front 16

hepatic jaundice (conjugation failure)

Back 16

neonatal physiological jaundice

Crigler-Najjer Disease

Front 17

hepatic jaundice (bilirubin transport disturbances)

2 and describe each

Back 17

Gilbert's Disease- increased bilirubin due to decreased activity of glucuronyl transferase

Dubin-Johnson Disease- increase in conjugated bilirubin in serum due to inability to get into bile

Front 18

Post hepatic jaundice

Back 18

obstruction of common bile duct by stone, neoplasms or spasms

Front 19

Lead poisoning

Back 19

ferrochelatase and ALA (aminoevulate) dehydrase sensitive to inhibition by lead

corproporphyrin III and aminoevulate accumulate in urine

Front 20

Acute Intermittent porphyria

Back 20

hydroxymethylbilane synthase deficiency

porphobilinogen and delta aminoevulate acid increased in urine

dark urine when exposed to light or air

not photosensitive

Front 21

erythropoeitic protoporphyria

Back 21

ferrochelatase deficiency

protoporphyrin increase in BM

photosensitivity

Front 22

varigate porphyria

Back 22

protoporphyrinogen oxidase deficiency

protoporphyrinogen IX and other intermediates in urine

photosensitivity

Front 23

hereditary coproporphyria

Back 23

coproporphyrinogen oxidase def

coproporphyrinogen III and other intermediates in urine

photosensitivity

Front 24

porphyria cutanea tarda

Back 24

chronic disease caused by uroporphyrinogen decarboxylase def

uroporphyrin increased in urine

most common

photosensitivity

Front 25

congential erythropoietic porphyria

Back 25

uroporphyrinogen III synthase def

uroporphyrinogen I and corproporphyrinogen I increased in urine

photosensitivity

Front 26

myoglobin structure and fxn

Back 26

in muscle and monomer

Front 27

hemoglobin structure and fxn

Back 27

in RBC and tetramer

Hemoglobin A has 2 alpha and 2 beta chains

Front 28

myoglobin oxygen binding curves

Back 28

greater affinity for o2

Front 29

hemoglobin oxygen binding curves

Back 29

sigmoidal due to cooperativity of 4 o2 molecules

Front 30

Bohr effect

Back 30

binding of o2 to hemoglobin decreases with a decrease in ph

Front 31

effect of 2,3 BPG on o2 binding to hemoglobin

Back 31

decreases binding to hemoglobin with increase in 2,3 BPG which helps individuals who live at high altitudes dissociate their o2 from hemoglobin

Front 32

which Fe transport oxygen

Back 32

Fe+2

Front 33

diabetes mellitus

Back 33

glycosylation of hemoglobin to HA1C occurs in this disease

H1AC used to monitor disease progression

Front 34

sickle cell anemia

Back 34

point mutation resulting in valine (hydrophobic) substitution for glutamate (hydrophilic) in B subunit

Malaria resistance

clumping due to hydrophobic valine and gets sickled

Front 35

thalassemias

Back 35

alpha or beta chain defects which lead to malaria resistance