Bio/Biochem Questions Flashcards
(52 cards)
when does removal of introns occur?
DNA –> mRNA
pre mRNA processing
electron carriers in the electron transport chain
cytochrome c: 1 electron carrier (cycles between ferrous and ferric state)
Complex I/NADH dehydrogenase complex: 2 electrons to ubiquinone, 4 H+ across the membrane
Complex III: 2 electrons to cytochrome c
Complex IV: 4 electrons from cytochrome c
O2: final electron acceptor, creates 2 molecules of water
what type of primer is most suitable for PCR?
suitable primers have a high GC content and have G or C base pairs at the 5’ and 3’ ends
nondisjunction
failure of homologous chromosomes to separate during anaphase I of meiosis OR the failure of sister chromosomes to separate during anaphase II of meiosis
why would protein synthesis be inhibited by D-alanine?
only L isomers of amino acids are used to form proteins during ribosomal protein synthesis
is growth rate faster under aerobic or anaerobic conditions?
aerobic
a much greater amount of ATP is produced to provide energy for reproduction (net 38 ATP vs net 2 ATP per molecule of glucose)
euchromatin vs heterochromatin
euchromatin is transcriptionally active while heterochromatin is not
actin filaments are
microfilaments
products of fermentation
pyruvic acid and glucose 6 phosphate (and other glycolysis intermediates) can still be produced
lactic acid or ethanol
acetyl coA will not be produced in anaerobic conditions
introduction of which amino acid substitution would result in the largest decrease in the entropic penalty associated with a protein folding into its native conformation?
Leu to Thr substitution at a surface-exposed site
switching a hydrophobic residue for a hydrophilic residue eliminates the entropic penalty associated with ordered water molecules around hydrophobic groups
germ layers
endoderm - epithelial tissues inside the body (digestive and respiratory tracts), bladder, liver, pancreas
mesoderm - bone, muscle, heart and circulatory system, internal sex organs
ectoderm - nervous system, dermis, hair, nails, eyes, ears, mouth, brain
bacterial vs. human cells
humans do not have a cell wall
they differ in ribosome units (eukaryotes have larger subunits) - 80S vs 70S in bacteria
bacterial DNA is circular
both use ATP synthase to make ATP
what hormone triggers ovulation?
luteinizing hormone
if a mutation in an intron affects the expression of an exon, the intron is likely to contain
splice receptor site
alternative splicing leads to changes in exon expressions
mature mRNA is not likely to contain:
introns
promoter sequences
transmembrane proteins are likely to contain:
signal sequence
facilitates transmembrane protein docking at the endoplasmic reticulum
during which step of cellular respiration is NADH neither oxidized nor reduced?
chemiosmosis
where is glomerular filtrate most concentrated?
medullary portion of the collecting duct
function of Na+ K+ ATPase during an action potential
restores resting potential by moving ions against their concentration gradient
3 sodium ions out of the cell, 2 potassium ions into the cell
resting membrane potential
more potassium ions inside than outside, more sodium ions outside than inside
-40 to -90 mV (negative)
to restore resting potential: 3 sodium ions out of the cell, 2 potassium ions into the cell
action potential: depolarization
cell becomes more +
positive ions enter the cell, Na+ enters through voltage-gated sodium channels
cell ends up extra positively charged (not neutral)
action potential: repolarization
cell becomes - again
positive ions leave the cell (Na+ channels close so no new sodium ions can enter, K+ channels open so potassium ions can leave)
action potential: hyperpolarization
after an action potential, cell becomes extra negatively charged because extra potassium ions leave the cell
sodium-potassium pump reestablishes resting potential
what enables a molecule to pass directly through the cell membrane?
small molecule
hydrophobic molecule
planar molecule
