Midterm (Exam 1) Flashcards
responsible for strong negative charge of nucleic acid
phosphate group
semiconservative replication of DNA
parental double helix divides into two double helix DNA with one parental strand in each of the two double helices
eukaryotic DNA
long and multiple origins of replication
single stranded DNA binding proteins
helix destabilizing proteins: keep the two DNA strands separate and protects against Nucleases that cleave single stranded DNA
DNA polymerase lll has a
5’ –> 3’ polymerase activity
3’ –> 5’ exonuclease
excise mismatched nucleotides during proofreading of newly synthesized DNA
DNA polymerase l activity uses
- 5’ –> 3’ exonuclease activty for RNA primers
- new DNA in 5’ –> 3’ polymerase direction
- proovereads new chain in 3’ –> 5’ exonuclease
pol alpha
multisubunit enzyme for eukaryotic DNA replication to initiate strand synthesis on the leading strand and beginning of okazaki fragments of lagging strand
unlike DNA polyermase, RNA polyermase doesn’t require a
primer and has no endo/exonuclease activity –> no mistmatch repair
RNA polymerase produces
small RNA’s: tRNA and rRNA
degeneracy
redundant genetic code where some amino acids have more than one triplet coding for it
Huntington disease
autosomal dominant
galactosemia
autosomal recessive disorder
locus heterogeneity
same disease phenotype by mutations at different loci
genomic imprinting
differential activation of genes, depending on parent
genomic imprinting example
- mutation on long arm of chromo 15 from father –> prader willi syndrome
- mutation on long arm of chromo 15 from from mother –> angelman syndrome
- GAA triplet
- intron
Friedreich ataxia
site of expansion and affected sequence caused by nucleotide repeat mutation; autosomal recessive
Friedreich Ataxia
1 in 800 live births
trisomy 21
most common chromsomal abnormality among still-borns which produces Edward syndrome
Trisomy 18
associated with Klinefelter syndrome
Trisomy XXy (Kayrotype 47)
Isochromosomes
chromosomes divide perpendicular to normal axis of division
Isochromosomes results in a chromosome that
has 2 copies of one arm and no copies of the other
Isochromosomes makes genetic material that is
substantially altered so most are lethal
most Isochromosomes observed in live births involve
the X, so features of Turner syndrome
MC inherited cause of mental retardation
Fragile X syndrome
- X exhibits breaks/gaps new long arm tip
permutations tend to become larger in successive generations
Sherman paradox
mitochondrian inheritance disease that causes progressive degen of pigment layer of retina, cardiac conduction abnormalities, ataxia, deafness, and dementia.
Kearns-Sayer syndrome
Familial hypercholesterolemia
autosomal dominant
hemophilia A
X-linked recessive
Glucose-6-phosphatase defect
Ian on Gierke Disorder in the liver
most prevalent amino acid metabolism disorder
PKU
Maple Syrup Urine disease results from deficiency in
branched-chain a-ketoacid dehydrogenase
what doesn’t occur in the nucleus
translation
7-sterol reductase deficiency (Smith-Lemi-Opitz) is in cholesterol biosynthesis results in
decrease levels of cholesterol and increased 7-dehydrocholesterol
increase levels of cholesterol and increased 7-dehydrocholesterol leads to
congenital anomalies of the brain, heart, genitalia and hands
urea cycle disorders include
hyperammonemia and ornithine transcarbamoylase
hyperammonemia causes
mental retardation, coma, and death
ornithine transcarbamoylase is the only
X-linked enzyme, others are autosomal recessive
Lyon hypothesis
one X chromosome in each cell is randomly inactivated early in the embryonic development of females
dosage compensation
females with two copies of the X chromo will produce X-linked gene products similar to males
X-linked dominant inheritance patterns
50% sons affected and 50% daughters affected
d-linked recessive inheritance patterns
50 % of sons affected and 50% of daughters heterozyous carriers
trisomy 13 produces
Patau syndrome
karyotype 45, X produces
Turner syndrome (female)
