Biochem - molecular, genes, lipids Flashcards
1
Q
excess ATP, dATP, decreased lymphocyte count
A
ADA (adenosine deaminase deficiency), AR mutation
2
Q
SCID
A
ADA (adenosine deaminase deficiency), AR mutation
3
Q
3 mo boy with delayed motor development, develops dystonia. 2 years later exhibits compulsive nail biting and banging head against wall. Develops renal failure and arthritis.
A
Lesch-Nyhan Syndrome - mutation in HGPRT
4
Q
excess uric acid + adenine + guanines
A
Lesch-Nyhan Syndrome - mutation in HGPRT (converts hypoxanthine to IMP and guanine to GMP
5
Q
HGPRT stands for:
A
HGPRT: Hyperuricemia Gout Pissed off (aggression, self-mutilation) Retardation (intellectual disability) DysTonia
6
Q
trmt for excess uric acid + adenine + guanines?
A
allopurinol or febuxostat (2nd line)
7
Q
degenerate codon definition
A
most a.a. are encoded by multiple codons
8
Q
unambiguous codon definition
A
each codon specifies 1 a.a.
9
Q
commaless codon definition
A
read from a fixed starting point as a continuous sequence of bases
10
Q
universal codon definition (exception to this?)
A
genetic code is conserved throughout evolution
exception in humans: mitochondria
11
Q
difference btwn DNA pol I and III
A
Pol III - 5’->3’ synthesis, proofreads with 3’->5’ exonuclease, LEADING + LAGGING strand
Pol I - same fxn as pol III, but can also excise RNA primer with 5’->3’ exonuclease, LAGGING strand only
12
Q
Rx that inhibits DNA topoisomerase in prokaryotes
A
fluoroquinolones
13
Q
leading strand orientation?
lagging strand orientation?
A
leading: 3’ –> 5’
lagging: 5’ –> 3’
14
Q
difference between transition and transversion
A
Transition - change within the same class
Transversion - change to a different class
15
Q
Nonsense mutation
A
Nucleotide substitution resulting in early stop codon.
16
Q
Missense mutation
A
Nucleotide substitution resulting in changed amino acid (conservative if new amino acid is similar in chemical structure).
17
Q
disease with defective nucleotide excision repair
A
xeroderma pigmentosum, AR
18
Q
disease with defective mismatch repair
A
HNPCC
19
Q
disease with defective non-homologous end joining
A
ataxia telangiectasia
20
Q
how is DNA and RNA template read and synthesized during transcription/translation?
A
DNA: 3 –> 5 (synthesized 5’–>3’)
mRNA: 5 –> 3 (synthesized N–C terminus)
21
Q
mRNA stop codons?
A
UGA = U Go Away. UAA = U Are Away. UAG = U Are Gone.
22
Q
where is the TATA box located?
A
promoter region
23
Q
3 types of eukaryotic RNA polymerase
A
I - rRNA (most numerous; “Rampant”)
II - mRNA (largest, “Massive”)
III - tRNA (smallest, “Tiny”)
24
Q
types of prokaryotic RNA polymerase
A
1 RNA polymerase, but makes all 3 (rRNA, mRNA, tRNA)
25
polyadenylation signal
AAUAA
26
P bodies
distinct foci in cytoplasm of eukaryotic cell - contains enzymes involved in mRNA turnover:
- decap and degrade unwanted mRNAs
- store mRNA until needed
- repress translation via miRNAs (related to siRNAs)
27
hnRNA
precursor to mRNA. undergoes processing in the nucleus:
- 5' cap
- 3' polyadenylation
- splicing out introns
28
snRNPs are found in? associated disease?
found in spliceosome (in nucleus, where pre-mRNA is cleaved form mRNA)
associated dz: SLE - contains anti-Smith antibodies against spliceosomal snRNPs
29
snRNPs are found in? associated disease?
found in spliceosome (in nucleus, where pre-mRNA is cleaved form mRNA)
associated dz: MCTD - contains anti-U1 RNP antibodies against spliceosomal snRNPs
30
what accounts for the degeneracy of genetic code?
tRNA wobble - accurate base pairing is required only in the first 2 nucleotide positions of an mRNA codon. Codons differing in the 3rd “wobble” position may code for the same tRNA/amino acid
31
What initiates mRNA translation?
GTP hydrolysis
32
Eukaryotic ribosomes
40S + 60S --> 80S (Even)
33
prokaryotic ribosomes
30S + 50S --> 70S (Odd)
34
what normally inhibits G1-to-S progression?
p53 and hypophosphorylated Rb
35
Neurons, skeletal and cardiac muscle, RBCs are considered to be what type of cells relative to the cell cycle?
permanent - remain in G0, regenerate from stem cells
36
Hepatocytes, lymphocytes are considered to be what type of cells relative to the cell cycle?
Stable (quiescent) - enter G1 from G0 when stimulated.
37
Bone marrow, gut epithelium, skin, hair follicles, germ cells are considered to be what type of cells relative to the cell cycle?
labile - never go to G0, divide rapidly with a short G1. Most affected by chemotherapy.
38
Nissl bodies?
found in RER in neurons- makes NTs for secretion
39
RER makes...
| most abundant in...
secreted proteins
| abundant in goblet cells of small intestines, plasma cells
40
SER makes...
| most abundant in...
steroids and detoxes drugs and poisons
| abundant in hepatocytes, adrenal cortex, gonads
41
residue added to proteins for trafficking to lysosomes
implicated in what disease
mannose-6-phosphate
I-cell disease (inclusion cell disease) - failure of the Golgi to phosphorylate mannose residues
42
patient with elevated serum proteases, glycosylases, lipases, hydrolases
I-cell disease (inclusion cell disease) - failure of the Golgi to phosphorylate mannose residues
43
I-cell disease (inclusion cell disease) features
```
coarse facial features
clouded corneas
restricted joint movement (claw shaped hands)
high plasma levels of lysosomal enzymes
Often fatal in childhood
```
44
Signal recognition particle (SRP)
cytosolic ribonucleoprotein that traffics proteins from the ribosome --> RER.
Absent or dysfunctional SRP --> proteins accumulate in the cytosol.
45
COPI
RETROgrade trafficking
| Golgi --> Golgi; Golgi --> ER.
46
COPII
ANTEgrade trafficking
Golgi --> Golgi; ER --> Golgi.
47
misfolded proteins in the RER are destined for..?
polyubiquinated and targeted by proteasomes
48
centriole configuration + function
centrioles (9x3)
two pairs form one centrisome
49
basal body configuration + function
9x3 (+2) nucleation site for growth of axoneme microtubules
50
centrisome configuration + function
```
2 centrioles (9x3)
serves as anchoring sites for proteins that anchor microtubules
```
51
cilia structure
9 + 2 (forms motile cilia; many projections)
9 + 0 (forms motile cilia; forms one projection from cell)
52
where is 9 + 0 microtubule configuration usually found?
non-motile (1˚ cilia) - serve as a sensory receptor on primitive node cells to establish R/L axis of body
53
situs inversus
congenital condition in which the major visceral organs are reversed or mirrored from their normal positions - dextrocardia on CXR
due to primary ciliary dyskinesia
54
situs inversus, chronic sinusitis, and bronchiectasis
Kartagener syndrome - immotile cilia prevents removal of mucus/pathogens from sinuses and respiratory tract
often have ectopic pregnancies or immobile sperm as well
55
Kartagener syndrome etiology
1° ciliary dyskinesia - immotile cilia due to a dynein arm defect
56
Drugs that affect microtubules
Microtubules Get Constructed Very Poorly):
- Mebendazole (anti-helminthic)
- Griseofulvin (anti-fungal)
- Colchicine (anti-gout)
- Vincristine/Vinblastine (anti-cancer)
- Paclitaxel (anti-cancer)
57
Ouabain MoA
binding to K+ site on Na/K ATPase
58
Cardiac glycosides
digoxin and digitoxin
59
digoxin and digitoxin MoA
directly inhibit the Na/K ATPase; leads to indirect inhibition of Na+/ Ca2+ exchange --> increase [Ca2+]i --> increase cardiac contractility.
60
Collagen Type I
associated dz?
Bone, Skin, Tendon, Dentin, Fascia, CORNEA, SCAR TISSUE
Osteogenica Imperfecta
61
Collagen Type II
cartilage, vitreous body, nucleus pulposus
62
Collagen Type III
Reticulin - BV, Skin, Uterus, Fetal tissue, GRANULATION tissue
63
Collagen Type IV
associated dz?
Basement membrane ("four" = "floor"), basal lamina, LENS
Alport Syndrome - defect in synthesis
Goodpasture Syndrome - ab attack
64
Vimentin stain
Connective tissue
"Men like to connect tissues"
65
Desmin
muscle (desMin)
66
GFAP
neuroglia
67
cytokeratin
epithelial cells
68
neurofilaments
neurons
69
proline + lysine should make you think of
preprocollagen
70
vitamin c is required for what? deficiency results in
hydroxylation of proline+lysine residues on collagen. Deficiency --> scurvy
71
triple helix of 3 collagen a chains is called this:
where is it formed?
deficiency results in:
pro-collagen, formed in RER
deficiency: osteogensis imperfecta
72
defect in cross-linking of tropocollagen molecules to form collagen FIBRILS
where does this cross-linking process normally occur? What d/o do you see this in?
extracellular (outside fibroblasts)
Ehler-Danlos
73
decrease in production of normal type I collagen
| sx?
Osteogenica imperfecta; autosomoal dominant
- factures
- blue sclerae
- hearing loss
- dental imperfections
74
ehlers-danlos syndrome - classical type
type V collagen deficiency; joint + skin sx (hyperextensible skin, hypermobile joints)
75
ehlers-danlos syndrome - vascular type
type III collagen deficiency: vascular (berry/aortic aneurysms) and organ rupture
76
patient w/ brittle, kinky hair, growth retardation, and hypotonia
Menkes disease - CT dz caused by impaired Cu absorption and transport (Cu is required for LYSYL OXIDASE to cross-link extracellular tropocollagen into collagen fibrils)
77
mutation in a glycoprotein that forms a sheath around elastin
Marfan syndrome - defect in fibrillin
78
deficiency in this enzyme that results in excess elastase activity.
patients should avoid this:
A1AT deficiency (emphysema)
must avoid smoking
79
what normally inhibits elastase?
| mutation results in..?
A1AT
mutation: emphysema
80
northern blot
RNA
81
south-western blot
DNA binding proteins (TFs) - using labeled oligonucleotide probes
82
Indirect elisa
uses a test antigen to see if a specific antibody is present in the patient's blood
83
direct elisa
uses a test antibody to see if a specific antigen is present in the patient's blood
84
sensitivity/specificity of elisa?
both approaches 100
85
FISH
fluorescence in situ hybridization - RNA/DNA probe to localize specific genes on chromsomes
86
type of nuclei acid used in cloning
mRNA
1) Expose mRNA to RT --> cDNA (no introns).
2) Insert cDNA fragments into bacterial plasmids w. antibiotic resistance genes.
3) Transform recombinant plasmid into bacteria.
4) . Surviving bacteria on antibiotic medium produce cDNA
87
dsRNA
RNAi (complementary to a mRNA sequence of interest; promotes degradation of target mRNA)
88
karyotyping uses what type of chromosomes?
metaphase chromsoomes
89
Codominance
example?
Both alleles contribute to the phenotype of the heterozygote.
Blood groups A, B, AB
α1-antitrypsin deficiency
90
Variable expressivity
example?
Phenotype varies among individuals with same genotype.
2 patients with NF1 may have varying disease severity.
91
Incomplete penetrance
example?
Not all individuals with a mutant genotype show the mutant phenotype.
BRCA1 mutation does not always result in breast/ovarian cancer
92
Pleiotropy
example?
One gene => multiple phenotypic effects
Untreated phenylketonuria (PKU) => light skin, intellectual disability, and musty body odor.
93
Anticipation
example?
Increased severity / earlier onset of disease in succeeding generations.
Trinucleotide repeat diseases (e.g., Huntington disease).
94
Loss of heterozygosity
example?
If a patient inherits or develops a mutation in a tumor suppressor gene, the complementary allele must be deleted/mutated before cancer develops. This is not true of oncogenes.
Retinoblastoma and the “two-hit hypothesis.”
95
Dominant negative mutation
heterozygote produces a nonfunctional altered protein that also prevents the normal gene product from functioning.
96
Linkage disequilibrium
certain alleles at 2 linked loci to occur together more often than expected by chance. Measured in a population
97
Mosaicism
example?
genetically distinct cell lines in the same individual that arises from mitotic errors after fertilization; can be somatic vs gonadal
McCune-Albright syndrome = lethal if somatic; survivable if mosaic.
98
somatic mosaicism
gonadal mosaicism
example?
Somatic mosaicism—mutation propagates through multiple tissues or organs.
Gonadal mosaicism—mutation only in egg or sperm cells.
McCune-Albright syndrome = lethal if somatic; survivable if mosaic
99
Locus heterogeneity
Allelic heterogeneity
locus = mutations at different loci can produce a similar phenotype (Albinism)
Allelic = different mutations in the same locus produce the same phenotype (β-thalassemia)
100
Heteroplasmy
Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrial inherited disease.
101
Uniparental disomy
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent; EUPLOID
compare heterodisomy vs isodisomy
102
heterodisomy vs isodisomy
Heterodisomy (heterozygous) = meiosis I error.
Isodisomy (homozygous) = meiosis II error or postzygotic chromosomal duplication of one of a pair of chromosomes, and loss of the other of the original pair.
103
Hardy-Weinberg population genetics eqns
p^2 + 2pq + q^2 = 1 and p + q = 1, which implies that:
p2 = frequency of homozygosity for allele p q2 = frequency of homozygosity for allele q 2pq = frequency of heterozygosity
104
carrier frequency, if an autosomal recessive disease
2pq (hardy weinberg)
105
frequency of an X-linked recessive disease in males? females?
males = q and in females = q^2
106
hyperphagia, obesity, intellectual disability, hypogonadism, and hypotonia.
Prader-Willi syndrome
107
gene from mom is normally silent and paternal gene is deleted/ mutated
Prader-Willi syndrome
108
inappropriate laughter (“happy puppet”), seizures, ataxia, and severe intellectual disability.
AngelMan syndrome
109
gene from dad is normally silent and Maternal gene is deleted/mutated.
AngelMan syndrome
110
predict inheritance: many generations, both male and female, affected
Autosomal dominant
111
predict inheritance: 25% of offspring from 2 carrier parents are affected; usually seen in only 1 generation
Autosomal recessive
112
predict inheritance: sons of heterozygous mothers have a 50% chance of being affected. No male-to-male transmission
X-linked recessive
113
Transmitted through both parents. Mothers transmit to 50% of daughters and sons; fathers transmit to all daughters but no sons.
X-linked dominant
114
Transmitted only through the mother. All offspring of affected females may show signs of disease.
Mitochondrial inheritance
115
chromosome mutation in ADPKD
16 - PKD1, 4 - PKD2 "16 letters in polycystic kidney"
116
chromosome mutation in FAP
5 - APC gene "5 words in polyp"
117
mutation in familial hypercholesterolemia
defective or absent LDL receptor; Elevated LDL, severe atherosclerotic disease early in life, and tendon xanthomas (classically in the Achilles tendon)
118
mutation in Hereditary hemorrhagic telangiectasia
d/o of blood vessels; telangiectasia, recurrent epistaxis, skin discolorations, AVMs, GI bleeding, hematuria.
119
mutation in Hereditary spherocytosis
spectrin or ankyrin defect; hemolytic anemia; increased MCHC. Treatment: splenectomy.
120
chromosome mutation in Huntington disease
4 - CAG trinucleotide repeat (anticipation); depression, progressive dementia, choreiform movements, caudate atrophy, and decrease levels of GABA and ACh in the brain.
121
mutation in Marfan's
Fibrillin-1 gene; tall with long extremities, pectus excavatum, hypermobile joints, and long, tapering fingers and toes (arachnodactyly); cystic medial necrosis of aorta
122
mutation in Multiple endocrine neoplasias (MEN)
MEN 2A and 2B are associated with ret gene.
123
chromosome mutation in NF1
17 - autosomal dominant; 100% penetrance with variable expression; café-au-lait spots and cutaneous neurofibromas.
124
chromosome mutation in NF2
22 - bilateral acoustic schwannomas, juvenile cataracts, meningiomas, and ependymomas
125
chromosome mutation in tuberous sclerosis
numerous benign hamartomas; incomplete penetrance, variable expression
126
chromosome mutation in von Hippel-Lindau disease
3 - VHL gene; development of numerous tumors
127
chromosome mutation in Cystic fibrosis
chromosome 7 - ATP-gated Cl- channel; mutation causes proteins to be retained in the RER (not transported to the cell membrane)
= secretes Cl− in lungs and GI tract
= reabsorbs Cl− in sweat glands
128
Cystic fibrosis pathophysiology and diagnosis
= secretes Cl− in lungs and GI tract
= reabsorbs Cl− in sweat glands
dx: increase Cl- in sweat, contraction alkalosis and hypokalemia because of ECF H2O/Na+ losses and concomitant renal K+/H+ wasting
129
Cystic fibrosis treatment
N-acetylcysteine = loosen mucus plugs (cleaves disulfide bonds within mucus glycoproteins)
Dornase alfa (DNAse) to clear leukocytic debris (mucolytic)
130
Cystic fibrosis complications
- Recurrent pulmonary infections (e.g., Pseudomonas)
- chronic bronchitis and bronchiectasis
- Reticulonodular pattern on CXR
- pancreatic insufficiency, malabsorption and steatorrhea
- nasal polyps
- meconium ileus in newborns
- Infertility in males (absence of vas deferens, absent sperm)
- Fat-soluble vitamin deficiencies (A, D, E, K)
131
chromosome mutation in Duchenne's
X-linked frameshift mutation (dystrophin gene (DMD) has the longest coding
region of any human gene -> increases chance of spontaneous mutations)
132
lab diagnosis of Duchenne's
increase CPK and aldolase
| WB and muscle biopsy to confirm
133
Symptoms of Duchenne's
- weakness begins in pelvic girdle muscles and progresses superiorly
- Pseudohypertrophy of calf muscles
- Gower maneuver—patients use upper extremity to help them stand up
- Onset before 5 years of age
- Dilated cardiomyopathy is common cause of death.
134
Becker's
X-linked point mutation in dystrophin gene (no frameshift as in Duchenne's)
135
post- pubertal macroorchidism (enlarged testes), long face with a large jaw, large everted ears, autism, mitral valve prolapse.
Fragile X syndrome (trinucleotide repeat d/o)
X-linked affecting methylation patterns of FMR1 gene
(2nd most common cause of intellectual disability)
136
chromsome mutation in Down syndrome
21
137
chromsome mutation in Edward syndrome
18
138
chromsome mutation in Patau syndrome
13
139
increased nuchal translucency and hypoplastic nasal nasal bone
decreased serum PAPPA, increased ßhCG
1st trimester Down Syndrome
140
low AFP, estriol
| increase hCG, inhibin
2nd trimester Down Syndrome
141
increased nuchal translucency and hypoplastic nasal nasal bone
decreased serum PAPPA, ßhCG
Edwards Syndrome (18) - first trimester
142
low AFP, estriol, hCG, inhibin
Edwards Syndrome (18) - second trimester
143
low β-hCG, PAPP-A
| increased nuchal translucency
Patau Syndrome (13)
144
evere intellectual disability, rocker- bottom feet, micrognathia (small jaw), low-set Ears, clenched hands, prominent occiput, congenital heart disease.
Death usually occurs within 1 year of birth.
Edwards syndrome (trisomy 18),
145
Severe intellectual disability, rocker- bottom feet, microphthalmia, microcephaly, cleft liP/Palate, holoProsencephaly, Polydactyly, congenital heart disease.
Death usually occurs within 1 year of birth.
Patau syndrome (trisomy 13)
146
intellectual disability, flat facies, prominent epicanthal folds, single palmar crease, gap between 1st 2 toes, duodenal atresia, Hirschsprung disease, congenital heart disease (most commonly ostium primum-type atrial septal defect [ASD]), Brushfield spots.
Down Syndrome (21)
147
Associated with increase risk of ALL, AML, and Alzheimer disease (> 35 years old).
Down Syndrome
148
these numbers make you think of...?
13, 14, 15, 21, and 22
Robertsonian translocation - these are acrocentric chromosomes (chromosomes with centromeres near their ends)
balanced translocations = no abnormal phenotype
Unbalanced translocations = miscarriage, stillbirth, and chromosomal imbalance (e.g., Down syndrome, Patau syndrome).
149
microcephaly, moderate to
| severe intellectual disability, high-pitched crying/mewing, epicanthal folds, cardiac abnormalities (VSD)
Cri du chat = cry of the cat
150
chromsome abnormality in Cri-du-chat syndrome
5 - microdeletion of short arm
| Cri du chat syndrome
151
“elfin” facies, intellectual disability, hypercalcemia (increased sensitivity to vitamin D), well-developed verbal skills, extreme friendliness with strangers, cardiovascular problems.
7 - microdeletion of long arm (deleted region includes elastin gene)
Williams syndrome
152
22q11 deletion
```
DiGeorge Syndrome - thymic, parathyroid, and cardiac defects.
"CATCH-22"
Cleft palate
Abnormal facies
Thymic aplasia -> T-cell deficiency
Cardiac defects
Hypocalcemia 2° to parathyroid aplasia
```
153
thymus develops from which branchial pouches?
Due to aberrant development of **3rd** and 4th branchial pouches
154
main processes that go on after a fasting state?
Hepatic glycogenolysis (major)
hepatic gluconeogenesis, adipose release of FFA (minor).
Glucagon, adrenaline stimulate use of fuel reserves.
155
main processes that go on during d1-3 of starvation?
Blood glucose maintained by:
hepatic glycogenolysis + gluconeogenesis
adipose release of FFA
muscle + liver shift fuel use from glucose -> FFA
156
Hepatic gluconeogenesis relies on these things
peripheral tissue: lactate + alanine
adipose tissue: glycerol and propionyl- CoA (from odd-chain FFA—the only TG components that contribute to gluconeogenesis)
157
main processes that go on after d3 of starvation?
Adipose stores (ketone bodies become the main source of energy for the brain)
After these are depleted, vital protein degradation accelerates, leading to organ failure and death.
158
Rate-limiting step of cholesterol synthesis?
HMG-CoA
Statins competitively and reversibly inhibit HMG-CoA reductase.
159
Pancreatic lipase
degradation of dietary triglycerides (TG) in small intestine.
160
Lipoprotein lipase (LPL)
degradation of TG circulating in chylomicrons and VLDLs. Found on vascular endothelial surface.
161
Hepatic TG lipase (HL)
degradation of TG remaining in IDL.
162
Hormone-sensitive lipase
degradation of TG stored in adipocytes.
163
LCAT
catalyzes esterification of cholesterol.
164
Cholesterol ester transfer protein (CETP)
mediates transfer of cholesterol esters to other
| lipoprotein particles.
165
ApoE
Mediates chyloµ remnant uptake by LDL receptors on hepatocytes (liver uptake)
166
ApoAI
Activates LCAT to esterify cholesterol on nascent HDL -> forms mature HDL
167
ApoCII
activates Lipoprotein Lipase on peripheral cells to deliver TGs
168
ApoB48
liver sends this out during the FED state to mediate chylo-µ transport from the gut into circulation (delivers dietary TG to peripheral tissues)
169
ApoB100
packaged into VLDL particles that the liver sends out during the FASTING state to deliver cholesterol + FA to peripheral tissues
170
chylomicron function? produced by?
1) delivers dietary TGs to peripheral tissue.
2) delivers cholesterol to liver in the form of chylomicron remnants, which are mostly depleted of their TGs.
3) Secreted by intestinal epithelial cells, packaged w/ ApoB48, ApoE, ApoCII and ApoCIII
171
VLDL function? produced by?
packaged with ApoB100; delivers HEPATIC TGs to peripheral tissues during FASTING state
172
IDL function? produced by?
Formed in the degradation of VLDL; delivers remaining TGs and cholesterol to liver.
173
LDL function? produced by?
Delivers hepatic cholesterol to peripheral tissues. Formed by hepatic lipase modification of IDL in the peripheral tissue. Taken up by target cells via receptor-mediated endocytosis.
174
HDL function? produced by?
Mediates reverse cholesterol transport from periphery to liver. Acts as a repository for ApoC and ApoE (which are needed for chylomicron and VLDL metabolism). Secreted from both liver and intestine. Alcohol increases synthesis.
175
Type I hyper-chylomicronemia
- pathophys?
- increased blood levels of?
ø Lipoprotein lipase or altered Apo C-II (AR)
forms excess Chylomicrons, TG, cholesterol
176
Type IIa—familial hyper- cholesterolemia
- pathophys?
- increased blood levels of?
ø LDL receptors (AD)
forms excess LDL, cholesterol
177
IV—hyper- triglyceridemia
- pathophys?
- increased blood levels of?
Hepatic overproduction of VLDL (AD)
forms excess VLDL, TG
178
familial dyslipidemia that causes
- pancreatitis
- hepatosplenomegaly
- eruptive/pruritic xanthomas
Type I hyperchylomicronemia (no risk for atherosclerosis)
179
familial dyslipidemia that causes
- accelerated atherosclerosis (may have MI before 20)
- tendon xanthomas
- corneal arcus
Type IIa—familial hyper- cholesterolemia - LDL increases atheroma risk
180
familial dyslipidemia that causes pancreatitis only
Type IV hyper- triglyceridemia
181
Telomerase
RNA dependent DNA polymerase (in other words, reverse transcriptase) that adds DNA to 3' end of chromosomes to avoid loss of genetic material w/ every dupliation
182
what is common to ALL tRNAs (both eukaryotic and prokaryotic)?
CCA at 3' end of tRNA; serves as a linker of the tRNA and the a.a.
183
difference btwn T arm and D arm of tRNA
T arm = contains sequence for tRNA ribosome binding
| D arm = contains dihydrouracil for tRNA recognition by the correct aminoacyl tRNA synthesis
184
linker of a.a. and the proper tRNA
aminoacyl-tRNA synthetase (1 per a.a.; serves as a matchmaker) - serves as a match maker and is responsible for adding the right a.a. to the right tRNA.
tough job.
185
collagen is comprised mostly of
glycine (followed by proline + lysine)
186
how does Arsenic affect glycolysis?
physical presentation of this?
causes it to produce 0 net ATP because it inhibits lipoic acid, which is present in the pyruvate dehydrogenase complex as well as the a-ketoglutarate dehydrogenase complex
physical presentation: vomiting, rice water stool, and GARLIC breath...say what?
187
gene mutation associated with Maturity-onset diabetes of the young (MODY)
Glucokinase
188
essential a.a.?
```
methionine
Valine
histidine
Isoleucine
Phenylalanine
Threonine
Tryptophan
Leucine
Lysine
```
PITT Essentially LIEd to LUCy about going to the MET with HIS ex VALerie
189
dyslipidemias - which two particles are responsible for causing pancreatitis?
chyloµ + VLDL
190
dyslipidemias - which two particles are responsible for causing fatty liver?
VLDL + IDL
191
dyslipidemias - which two particles are responsible for causing pancreatitis?
LDL + lipo(a)
192
what happens if hepatic lipase is mutated?
increased HDL - good mutation to have!
193
what happens if ABCA1 is mutated?
ABCA1 functions to remove excess cholesterol + FFA from peripheral tissues
∆ ABCA1 = Tangier's disease - severe reduction in HDL particles and accumulation of cholesterol in many body tissues
Presentation:
- Tangier's tonsils (extremely enlarged, orange/yellow)
- premature atherosclerosis
- slightly elevated amounts of fat in circulation
- other signs
- > enlarged spleen, liver
- > clouding of cornea
- > early onset of cardiovascular disease
