week 3 Flashcards
Tay Sachs Disease
lysosomal storage disease; buildup of undigested cell products inhibits cell functioning and results in cell death
secretary granules
vesicle containing secretary granules found near the plasma membrane; present in cells that use regulated secretion in response to a signal
Lack of Electron Transfer Flavoprotein (ETF) or the ETF: CoQ reductase
leads to glutaric acidemia type II; build up of glutaric acid due to amino acids getting degraded for energy; can get severe hypoglycemia and death; severe symptoms under fast fatty acid oxidation symptoms; more mild forms may be treated with riboflavin administration
Carnitine deficiency
inability to transfer amino acids into the mitochondria; leads to weakness, fasting hypoglycemia, triglyceride accumulation in muscles and liver; treat by adding carnitine to the diet
Primary carnitine deficiency
unable to get carnitine into the cells, treating with carnitine may help; also diet with high amount of short chain fatty acids which can diffuse into mitochondria without transporter; low plasma carnitine levels in the urine because it can’t get in the cells
Secondary carnitine deficiency
defect in fatty acid oxidation; all of the carnitine gets used up and gets stuck on acyl group, forming acyl-carnitines, which accumulate, leading to detrimental nervous system functioning; short chain fatty acid diet doesn’t help because still have a fatty acid oxidation defect
MCAD deficiency
single AA change from K to E (positive to negative) leads to unstable protein; hypoglycemia when fasting, can’t fully do fatty acid oxidation because medium chain dicarboxylic acids build up along with hexanoylglycine; don’t have enough energy for gluconeogenesis; lack of ketone bodies because lack of acetyl CoA
Zellweger syndrome
lack of peroxisomes, accumulation of very long chain fatty acids and branched fatty acids, which has negative effects on nervous system
Refsum disease
loss of alpha oxidation (phytanic acid oxidase) which leads to phytanic acid accumulation (branched chain), which is incorporated into myelin sheath, causing neural dysfunction
Adrenoleukodystrophy
mutation in transport protein on peroxisome membrane, leads to accumulation of very long chain fatty acids which affect adrenal glands and nervous system; X linked disorder; treatment with Lorenzo’s oil, early treatment can slow disease progression
Acyl-CoA oxidase deficiency
enzyme that does first step of oxidation to oxidize the fatty acid and produce hydrogen peroxide; 2 types- ACOX1- straight chain enzyme deficiency- neonatal hypotonia, seizures, death; ACOX2- branched chain enzyme- severe neurological disfunction, similar to Refsum
Jamaican vomiting sickness
eating unripe ackee fruit produces hypoglycin toxin which is metabolized into compound which tightly binds FAD, interferes with short and medium chain acyl CoA DH; inhibits gluconeogenesis by the reduction of NADH and acetyl CoA levels; severe hypoglycemia and elevated fatty acids in blood, along with dicarboxylic acids; can be fatal
G6PDH deficiency
leads to lack of NADPH, detrimental to RBCs when they undergo oxidative stress, oxidized glutathione can’t be converted to the protective, reduced form which neutralizes the oxidative stress; damage to RBC membrane leads to cell lysis and thus anemia; hidden disorder unless exposed to oxid. stress (fava beans, anti-malarial drugs); X linked recessive, gives selective resistance to malaria- growth of parasite in the RBCs leads to membrane damage and cell lysis (b/c no NADPH), cells invected then are lysed and removed from circulation- more mild disease
Sickle cell resistance to malaria
HbS/HbA cells (carrier) have different miRNA subset produced- become incorporated into parasite mRNA disrupting maturation of the parasite; placing a certain 3 miRNA molecules into a normal (non-carrier) person will give a resistance to malaria
Rapoport Leubering shunt
1,3 BPG from glycolysis can be used to generate 2,3 BPG in RBCs which then stabilizes the T state (deoxy)
Radical chain terminators
anti-oxidants, reduce damage from radicals; vitamin A (beta carotene), vitamin E, and vitamin C
Lou Gehrig’s disease (ALS)
mutated superoxide dismutase enzyme (converts superoxide to hydrogen peroxide in mito) which leads to oxidative damage
Burkitt’s lymphoma
chromosomal translocation places myc gene under control of highly active promoter- leads to constant expression of myc and uncontrolled cell division in lymphocytes; myc is converted from proto-oncogene to oncogene; myc results in phosphorylation of G1 CDK which activates it, and CDK phosphorylates and inactivates Rb to release the E2F TF- S phase transcription of cyclins needed for the active cyclin-CDK complex
Prader willi syndrome
deletion on paternal chromosome 15, corresponding genes are imprinted (off) on maternal chromosome- there are no active genes; short stature, mental delay, decreased muscle tone, unregulated appetite- obesity; can only be passed down by males because females will reset the genes during gametogenesis to be imprinted
Angelman syndrome
deletion on maternal chromosome 15, corresponding paternal genes are imprinted (off), meaning no genes are expressed; normal development during first year and then delayed development microcephaly, seizures, language deficit, motor problems; can only be passed down by females because males will reset the methylation pattern and the mutated genes are imprinted/switched off
Sickle cell disease
mutation in the beta chain from glutamate to valine creates a hydrophobic patch on the surface of the deoxy Hb molecule, causing aggregation with other deoxy molecules; these aggregates distorts the shape of the RBC into a sickle, which clump together in blood vessels, blocking blood flow
Ehlers Danlos
defects in structural collagen genes and enzymes involved in post TL mod (lysyl hydroxylase, procollagen N peptidase); very mobile joints and skin hyperextensivity, tissue fragility
Osteogenesis imperfecta
family of mutations in structural collagen genes; usually involves mutation of glycine to another residue, which disrupts the triple helix structure, making it unstable and resulting in very fragile bones and teeth
Williams Syndrome
mutation in elastin genes results in narrowing or aorta or arteries (elastin is dominant protein in arteries); may lead to supravalvular aortic stenosis, hypertension, hypercalcemia, small, widely spaced teeth
