BIO 311C FINAL EXAM STUDY GUIDE QUESTIONS AND
ANSWERS 2026/2027 | COMPLETE EXAM REVIEW
operons consist of: - ANS ✔✔promoter, operator, coordinately related cluster of genes whose
products function in a common pathway
are human genes organized in operons? - ANS ✔✔no
responses caused by epinephrine binding to receptor - ANS ✔✔--response may be relaxation of
muscles through a G-protein pathway
--other triggers contraction of muscles by opening calcium ion channels
insulin receptor is what type of receptor? - ANS ✔✔tyrosine kinase
where is tRNA made? - ANS ✔✔nucleus
explain sucrose-H+ co-transporter - ANS ✔✔--H+ pump creates H+ gradient
--as H+ moves down its gradient through the co-transporter, energy from that moves sucrose
against its gradient also through the co-transporter
what determines the net direction of water movement across a semi-permeable membrane? -
ANS ✔✔solutes (water follows solute, moving from low solute concentration to high solute
concentration)
advantages of using second messengers instead of another protein - ANS ✔✔--small molecules,
so easier to make
--can diffuse around cytoplasm
,2 ways bacteria can turn off tryptophan pathway? - ANS ✔✔1. end-product feedback inhibition:
tryptophan can bind to an earlier enzyme in the pathway in order to stop further production
2. gene regulation: tryptophan acts as a co-repressor and binds to inactive repressor; the now-
active repressor binds to operator to end further transcription of trp operon
examples of keeping signal transduction pathways under control (3) - ANS ✔✔--active cAMP
changed to AMP (phosphodiesterase)
--excess calcium ions cleared from cytosol
--phosphatase enzymes inactivate proteins
silent mutation - ANS ✔✔(ex. could be: base substitution)
results in triplet codon that codes for same amino acid as before and would not affect
functionality of protein
by what means could a gene be active in one cell type and inactive in another? - ANS
✔✔specialized cells have different sets of control proteins to turn on only certain genes; all
genes are present in every cell, but transcription factors and activator proteins vary; also
different control proteins
antiport - ANS ✔✔membrane protein that transports 2 different substances in opposite
directions (ex: Na/K pump)
early arguments supporting protein as the genetic material - ANS ✔✔--20 different amino acids
--great variety in shapes
--known to control cell reactions
tRNA function - ANS ✔✔carries amino acids to ribosome for translation
, why can't eukaryotes do coupled transcription and translation? - ANS ✔✔--nucleus is barrier
separating the processes
--eukaryotes do RNA processing (splicing out introns, etc.)
aquaporin - ANS ✔✔passive protein channel in which water can pass through and go into cell
(faster way for water to cross than simple diffusion, larger amounts of water can pass through)
early arguments supporting DNA as genetic material - ANS ✔✔--doubles before cell replication
--4 different nucleotides
introns - ANS ✔✔noncoding segments of mRNA that are cut out
activator proteins-- binding location and effect ? - ANS ✔✔--bind to enhancer (in eukaryotes)
and promoter (in prokaryotes)
--greatly increase the rate of transcription
repolarization - ANS ✔✔K+ channels open, allowing efflux of K+ (down its gradient), makes
outside cell more positive and inside more negative
meaning of redundant code - ANS ✔✔multiple codons can code for the same amino acid (but
codons can only code for one amino acid each)
H bonds between C and G - ANS ✔✔triple bond
H bonds between A and T - ANS ✔✔double bond
meaning of anti-parallel structure - ANS ✔✔DNA strands run in opposite directions
ANSWERS 2026/2027 | COMPLETE EXAM REVIEW
operons consist of: - ANS ✔✔promoter, operator, coordinately related cluster of genes whose
products function in a common pathway
are human genes organized in operons? - ANS ✔✔no
responses caused by epinephrine binding to receptor - ANS ✔✔--response may be relaxation of
muscles through a G-protein pathway
--other triggers contraction of muscles by opening calcium ion channels
insulin receptor is what type of receptor? - ANS ✔✔tyrosine kinase
where is tRNA made? - ANS ✔✔nucleus
explain sucrose-H+ co-transporter - ANS ✔✔--H+ pump creates H+ gradient
--as H+ moves down its gradient through the co-transporter, energy from that moves sucrose
against its gradient also through the co-transporter
what determines the net direction of water movement across a semi-permeable membrane? -
ANS ✔✔solutes (water follows solute, moving from low solute concentration to high solute
concentration)
advantages of using second messengers instead of another protein - ANS ✔✔--small molecules,
so easier to make
--can diffuse around cytoplasm
,2 ways bacteria can turn off tryptophan pathway? - ANS ✔✔1. end-product feedback inhibition:
tryptophan can bind to an earlier enzyme in the pathway in order to stop further production
2. gene regulation: tryptophan acts as a co-repressor and binds to inactive repressor; the now-
active repressor binds to operator to end further transcription of trp operon
examples of keeping signal transduction pathways under control (3) - ANS ✔✔--active cAMP
changed to AMP (phosphodiesterase)
--excess calcium ions cleared from cytosol
--phosphatase enzymes inactivate proteins
silent mutation - ANS ✔✔(ex. could be: base substitution)
results in triplet codon that codes for same amino acid as before and would not affect
functionality of protein
by what means could a gene be active in one cell type and inactive in another? - ANS
✔✔specialized cells have different sets of control proteins to turn on only certain genes; all
genes are present in every cell, but transcription factors and activator proteins vary; also
different control proteins
antiport - ANS ✔✔membrane protein that transports 2 different substances in opposite
directions (ex: Na/K pump)
early arguments supporting protein as the genetic material - ANS ✔✔--20 different amino acids
--great variety in shapes
--known to control cell reactions
tRNA function - ANS ✔✔carries amino acids to ribosome for translation
, why can't eukaryotes do coupled transcription and translation? - ANS ✔✔--nucleus is barrier
separating the processes
--eukaryotes do RNA processing (splicing out introns, etc.)
aquaporin - ANS ✔✔passive protein channel in which water can pass through and go into cell
(faster way for water to cross than simple diffusion, larger amounts of water can pass through)
early arguments supporting DNA as genetic material - ANS ✔✔--doubles before cell replication
--4 different nucleotides
introns - ANS ✔✔noncoding segments of mRNA that are cut out
activator proteins-- binding location and effect ? - ANS ✔✔--bind to enhancer (in eukaryotes)
and promoter (in prokaryotes)
--greatly increase the rate of transcription
repolarization - ANS ✔✔K+ channels open, allowing efflux of K+ (down its gradient), makes
outside cell more positive and inside more negative
meaning of redundant code - ANS ✔✔multiple codons can code for the same amino acid (but
codons can only code for one amino acid each)
H bonds between C and G - ANS ✔✔triple bond
H bonds between A and T - ANS ✔✔double bond
meaning of anti-parallel structure - ANS ✔✔DNA strands run in opposite directions
