Midterm Flashcards
what is responsible for the strong negative charge of nucleic acid
phosphate group
what is semiconservative replication of DNA
parental double helix divides into two double helix DNA with one parental strand in each of the two double helices
what is very long and has multiple origins of replication
eukaryotic DNA
what is single stranded DNA binding proteins
aka: helix destabilizing proteins - keeps the two DNA strands separate and protects the DNA from nucleases that cleave single stranded DNA (picture of all kids, fat kid is answer)
what has a 5’ -> 3’ polymerase activity
DNA polymerase
what is 3’ -> 5’ exonuclease activity used to
exercise mismatched nucleotides during proofreading of newly synthesized DNA
DNA polymerase uses _____ activity for RNA primers
5’ -> 3’ exonuclease
a multisubunit enzyme used during eukaryotic DNA replication to initiate strand synthesis on the leading strand and beginning of okazaki fragments of lagging strand
pol alpha
does not require a primer and has no known endonucleases or exonucleases activity, therefore no ability to repair mismatch
RNA polymerase
enzyme that produces the small RNA including tRNA’s and small ribosomal RNA
RNA polymerase III
when genetic code is redundant where some amino acids have more then one triplet coding for it
degeneracy
autosomal dominant disorder
huntington disease
autosomal recessive disorder
galactosemia
normal parent with heterozygote, ____% probability that child will get either affected or normal gene
50
causation of the same disease phenotype by mutations at different loci
locus heterogeneity
the differential activation of genes, depending on the parent from which they are inherited. the mutation on long arm of chromosome 15 from father - prader-willi syndrome, from mother - angelman syndrome
genomic imprinting
what is trismony 13
patau syndrome
(GAA triplet) (intron): site of expansion and affected sequence caused by nucleotide repeat mutation - autosomal recessive
friedreich ataxia
trismony 21
incidence 1 in 800 births, down syndrome
trismony 18
produces edward syndrome - most common chromosome abnormality among still borns
trismony XXY (kayrotype 47)
klinefelter syndrome
DNA vs RNA: which has no exo’s and endo’s
RNA
MC inherited cause of mental retardation, the X exhibits breaks and gaps near the tip of the long arm (down syndrome is a chromosomal abnormality, and NOT inherited gene mutation)
fragile x syndrome
when permutations tend to become larger in successive generations
sherman paradox
mitochondrial inheritances disease
kearns-sayer syndrome
autosomal dominant
familial hypercholesterolemmia
x linked recessive
hemophilia A
glucose 6 phosphatase defect results in
la von gierke disorder in the LIVER
most prevalent amino acid metabolism disorder
phenylketouria (PKU)
results from deficiency in branched chain alpha-ketoacid dehydrogenase
maple syrup urine disease
T/F: Menkes disease is X linked
T
familial hypercholesterolemia is an autosomal ___ disease
dominant
what enzyme is not there in phenylketonuria and what does it result in
phenylalanine hydroxylase, severe mental retardation d/t disruption of myelination and protein synthesis
what is the prevalence of trisomy 21 and 45X
trisomy 21 - 1/800
45X - 1/5000 females
what chromosome has part deleted in Wolf-Hirschhorn syndrome
4
what is the trisomy XXY called
Klinefelter syndrome
Turner syndrome people with X from father have higher/lower IQ’s than from their mother
higher
what is trisomy 13 known as
patau syndrome
what is another name trisomy 18
edward syndrome
what is trisomy 21 cause and what is the incidence
down syndrome
1/800
chromosomal diseases are the leading cause of _____ and _____
retardation and pregnancy loss
what disease is characterized by degeneration of pigment of retina, cardiac conduction abnormalities, ataxia, deafness, and dementia
kearns-sayer syndrome
what are the distinctive facial appearances in fragile x syndrome? several photos that you must ID so dont skip them
large ears, long face
what is the most common inherited cause of mental retardation
fragile x syndrome (downs is chromosomal abnormality, not gene mutation)
is there father-son transmission?
no
even though x linked traits are like autosomal recessive, why do only half the cells in a female express the disease allele
only one X chromosome is active in an individual cell
what chromosome has different syndromes is the mutation is from the mother vs the father and what are the 2 syndromes
- chromosome 15
- father - prader willi syndrome
- mother - angelman
what is locus heterogeneity
single disease phenotype can be caused by mutations at different loci
what is it called when 2 or more offspring present with an auto dominant disorder when there is no family history
germline mosaicism
homozygous/heterozygous is more sever in dominant diseases
homozygous
dominant diseases are more vertical/horizontal, which recessive are more vertical/horizontal
dominant - vert
recessive - horiz
vert seen in generation after generation
T/F heterozygous carriers for recessive diseases are much more common than affected affected homozygotes
T
werner syndrome
premature aging, cancer, genome instability; accessory 3’ exonuclease and DNA helicase
BCRA - 2
breast and ovarian cancer, repair by homologous recombination
proofreading of DNA by exonucleases is via ____ activity and RNA is via _____
DNA - 3’->5’
RNA - 5’ ->3’
what are the two purines in both RNA and DNA
adenine and guanine
which pyrimidine is in both DNA and RNA
cytosine
which is only in DNA and which is only in RNA
thymine, Uracil
purine and pyrimidine bases -> ______ -> nucleotides-> ______
nucleosides, nucleic acids
what is a nucleoside
addition of a pentose sugar to a base (ribose or deoxyribose to cytosine)
5’ end of the nucleotide chain is always on the L or R
L
one complete turn of the DNA duplex occurs every ___ base pairs
10
A is always with __ and G is always with ___ by ___ bonds
AT
GC
hydrogen
