Flashcards in Molecular Bio Deck (114)
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91
True or false? mitochondria are more dynamic in high energy cells
false, less dynamic. become more fixed in high energy cells where they are packed tightly between myofibrils
92
Do mitochondria retain their own DNA?
yes
93
Mitochondria transfer RNAs are highly variable. changes in mt tRNAs have been linked to over 200 disease states. true or false?
true
94
Accumulation of ___ generated by the respiratory chain can cause mito DNA damage
ROS
note: ROS increase with age, and the brain is particularly susceptible
95
list the layers of the epidermis
granular, prickle, basal, basal lamina
96
Olfactory receptors are what type of receptor?
G protein coupled receptor
97
Describe the flow of action potential from olfactory receptor
relayed via axon to brain to glomeruli
98
Where are glomeruli found?
olfactory bulbs
99
Define totipotency
ability of a cell to give rise to all cells of an organism, including embryonic and extra embryonic tissues ex: zygote
100
Define pluriptoency
ability of a cell to give rise to all cells of the embryo and subsequently adult tissues ex: embryonic stem cells
101
define multipotency
ability of a cell to give rise to different cell types of a given lineage ex: adult stem cells
102
true or false? founder stem-cell populations stay small; transit amplifying divisions let them generate and renew a big adult structure
true
103
Explain the immortal strand hypothesis
to combat passing on mutation, stem cells divide asymmetrically, passing down a template parental strand
104
How are ES cells derived?
what for zygote to become blastocyst and then take inner cell mass and culture on plate
105
True or false? Adult stem cells are tissue specific
true
106
give the function of the following types of RNAs:
tRNA; snRNA; snoRNA; miRNA; siRNA
tRNA: adaptor between mRNA and AAs
snRNA: splicing of pre-mRNA
snoRNA: chemically modify rRNAs
miRNA: regulate gene expression - block translation of specific mRNAs
siRNA: turn off gene expression
107
Explain eukaryotic transcription initiation
TFIID binds to TATA box; recruitment of other TFs; formation of transcription initiation complex; Phosphorylation of CTD by TFIIH = elongation
108
The genetic code is degenerate. True or false?
True
109
What is the anticodon loop on a tRNA molecule?
a set of 3 consecutive nucleotides that pair with a complementary codon in an mRNA molecule
110
What is the 3'CCA terminal region of a tRNA molecule?
the region which binds the AA that matches the corresponding codon
111
Some tRNAs require accurate base-pairing only at the first two positions of the codon and can tolerate a mismatch at the third (wobble) position. This wobble base pairing explains why.....
so many of the alternative codons for an AA differ only in their third nucleotide
112
UAA, UAG and UGA are what type of codons
stop codons
113
Protein transfer/transport to various compartments is guided by ___ signals. Signal ___ remove signal after protein reaches final destination
sorting; peptidases
114
