test 3 baldini Flashcards
What are the blood group antigens composed of?
A Ceramide (sphingosine with fatty acid)
no antigen for type O
add Galactosamine= type A
add galactose = type B
Spur cell anemia
Uncommon hemolytic anemia where increased cholesterol results in rigid “spur” red blood cells which spleen destroys
What’s a liposome?
When a lipid drops in water it forms a sphere with a polar surface on the outside and inside of the sphere. Drugs, enzymes, and DNA can be packaged on the inside
how does glucagon/epinephrine cause glycogen breakdown?
- Activates adenylate cyclase to release cAMP
- cAMP activates protein kinase A
- PKA phosphorylates/activates glycogen phosphorylase kinase
-
Glycogen phosphorylase kinase phosphorylates glycogen phosphorylase to activate it to then breakdown glycogen
(calcium promotes activation of phosphorylase kinase)
how does insulin stimulate glycogen synthesis?
It stops the breakdown and stimulates synthesis
1. Insulin activates a receptor tyrosine kinase
2. This activates phosphoprotein phosphatase (phosphatases remove phosphate)
3. Dephosphorylates glycogen synthase to activate it
stops breakdown: Phosphoprotein phosphatase also removes the phosphate from glycogen phosphorylase kinase and glycogen phosphorylase to stop glycogen breakdown
what is Von Gierke disease? Type I GSD
deficient in Glucose-6-phosphate
severe hypoglycemia, blood lactidosis, blood uric acidosis, hepatomegaly
Pompe disease? Type II GSD
1,4-glucosidase deficiency
“Pompe trashes the pump”
cardiomyopathy, hypotonia, enlarged tongue
infant death due to cardiac failure
Cori disease? Type III GSD
debranching enzyme deficiency
milder von gierke
“AB - CD”
Andersen disease? Type IV GSD
Branching enzyme deficiency
death from liver cirrhosis due to glycogen accumulation
failure to thrive in infants
“AB-CD”
McArdle disease? Type V GSD
Skeletal muscle glycogen phosphorylase deficiency
muscle cramps and pain on exertion, easily fatigued
normal life expectancy
what is type 1a CDG
Phospomannose mutase 2 deficiency
cannot convert mannose 6-P into mannose 1-P
presents with seizures, hypotonia, microcephaly, stroke-like episodes
Test by detecting underglycosylated serum transferrin
What is type 1b CDG
Deficiency in phophomannose isomerase
cannot convert mannose 6-P into fructose 6-P
presents with seizures, hypotonia, microcephaly, stroke-like episodes
Test by detecting underglycosylated serum transferrin
Hereditary fructose intolerance
deficiency in Aldolase B
fructose and ATP is “trapped” in liver due to fructose 1-phosphate not being able to convert
hypoglycemia and liver damage
what is GALT
deficiency in galactose 1-P uridyltransferase and cannot form UDP-galactose to eventually become glucose
Classic severe form with severe retardation if not treated, cataracts
UDP-glucose-4-epimerase deficiency?
similar to GALT if present in all cells, but ok if just red blood cells
cataracts and retardation if not treated
what is Crigler-Najjar syndrome?
deficiency in UDP-glucoronyltransferase
cannot conjugate bilirubin to excrete it in bile and instead transfers to lipids resulting in kenicturus (brain damage)
normally takes a few weeks to activate in newborns
what is surfactant made of and why is it important?
AKA lecithin- a phosphatidyl choline with two fatty acids made of palmitoyl groups
Decreases surface tension of the fluid layer to prevent atelectasis (lung collapsing due to “sticking together” at end of exhaling)
deficiency results in respiratory distress syndrome, which can also occur in adults whose type II cells (secretes surfactant) are destroyed from chemo
where does sphingolipid breakdown occur?
in the lysosomes
What is Tay-Sachs disease?
deficiency in hexosaminidase A
cherry-red spot, with NO hepatosplenomegaly, neurodegeneration
GM2 ganglioside accumulates
Neimann-Pick disease?
Deficient in Sphingomyelinase
“sphinger picks nose”
cherry-red spot, WITH hepatosplenomegaly, neurodegeneration
sphingomyelin accumulates
Gaucher disease?
deficiency in glucocerebrosidase
hepatosplenomegaly, anemia, thrombocytopenia, Gaucher cells
Fabry disease?
deficiency in alpha-galactosidase A- X linked
“fabry is fabulous” affects the skin
angiokeratomas, lack of sweat, renal disease
ceramide trihexoside accumulates
Fatty acid synthesis step 1?
Committed step
Acetyl-CoA carboxylase with biotin (B7) attached
converts Acetyl-CoA using HCO3+ATP into
Malonyl-CoA
Fatty acid synthesis step 2?
Malonyl-CoA donates carbons to form fatty acids such as Palmitic Acid (requires 8 Acetyl-CoA)
fatty acid synthesis requires a bunch of NADPH
