UofT BIO130 Test 1 Questions With Complete Solutions
5' pre-mRNA capping Correct Answers 1. Helps to protect
RNA from exonucleases
2. Completed before mRNA fully transcribed
A coiled coil Correct Answers Super secondary structure. (Two
helices wrap around to minimize e.g. exposure of hydrophobic
aa chain)
Amphipathic (different biochemical or biophysical properties on
different sides) alpha helix.
Coiled coils (strong structures that can give elasticity) are found
in alpha-keratin of skin, hair and also myosin motor proteins.
A number of Eukaryotic RNA polymerases needed Correct
Answers Each of these RNAPs is a multi-subunit protein. Each
RNAP is responsible for transcription of different RNAs. RNA
polymerase I, RNA polymerase II, RNA polymerase III.
Activator protein Correct Answers a regulatory protein that
binds to specific sites on DNA and stimulates transcription;
involved in positive control. Are in prokaryote and eukaryote
and help get out of abortive phase. It gives kiss to unleash RNA
creation.
Amino Acid Structure Correct Answers 1. Proteins are
composed of amino acids
2. The amino acid side-chain or R group is variable and
determines the type of amino acid
3. Major categories of amino acid: [acidic, basic, uncharged
polar, nonpolar] -> determined by particular side group
,4. All have NH2, carboxyl, and alpha carbon is where all other
atoms and groups are attached
Anti parallel beta sheet Correct Answers Protein chains running
in opposite directions.
1N and 1C terminus (one polypeptide chain) but 3 strands of
beta chain.
Backbone Correct Answers Backbone atoms N-C(a)-C-N are all
of the protein's atoms except for the side chain.
Bacterial DNA replication Correct Answers 1. Origin of
replication
2. Binding of initiator proteins
3. Unwinding by helicase
4. Binding of single-strand binding proteins
5. RNA primers made by primase
6. DNA polymerase
7. Sliding clamp holds polymerase onto DNA
8. Nick sealing by DNA ligase
Base Excision Repair (BER) Correct Answers
PROOFREADING: A DNA repair pathway that involves
excision of a damaged base by DNA glycosylase, followed by
cleavage of the DNA backbone adjacent to the site by an AP
endonuclease. Nick translation, DNA polymerization, and
ligation complete the repair. Takes out deaminated C and DNA
polymerase adds new nucleotide.
Base pairing Correct Answers 1. Holds the DNA double helix
together (Purine lines up with pyrimidine)
,2. A-T 2 H-bonds (how DNA lines up)
3. G-C 3 H-bonds (more bonds=stickier)
Bases Correct Answers Pyrimidine = 1 ring
(U C (see) T (the) pyramids) - longer name=shorter structures
Purine = 2 ring
(Purine is pure and has G(od) and A(ngles) short name=longer
structure).
Central Dogma (refined) Correct Answers DNA undergoes
transcription.
mRNA= messenger
tRNA=transfer (transport AA's, and for protein synthesis)
rRNA=part of ribosome
See slide 44.
Chaperone proteins Correct Answers assist in folding other
proteins
Chromatin Correct Answers Substance found in eukaryotic
chromosomes that consists of DNA tightly coiled around
histones
Chromatin packing and re-modeling Correct Answers
Chromatin remodeling complexes and histone modifying
enzymes are examples of proteins that can make changes in
chromatin structure and alter access to DNA for replication or
transcription. (Heterochromatin, Euchromatin)
Chromatin: levels of organization (really look at slides) Correct
Answers The net result is that each DNA molecule has been
, packaged into a mitotic chromosome that is 10,000 times shorter
than its extended length (packing/unpacking, requires ATP)
Euchromatin (before packed into nucleosome) and
heterochromatin (after packed into nucleosomes).
Chromatin: levels of organization Correct Answers -Short
region of DNA double helix
-"beads-on-a-string" form of chromatin (yellow is protein, red is
DNA and DNA is wrapped around nucleosome)
-Chromatin fiber of packed nucleosomes (30nm fiber)
-Chromatin fiber folded into loops
-Entire mitotic chromosome (centromere in middle)
Chromosome solution cont. Correct Answers In humans 23
pairs.
-Each chromosome (DNA wrapped around protein) contains a
single, long, linear DNA molecule and associated proteins called
chromatin (DNA+protein)
-Chromatin is tightly packaged, BUT the DNA must remain
accessible for transcription, replication, and repair.
-Chromatin is DYNAMIC (can make it more compact or less)
Comparing genome sizes Correct Answers Genome size is not
always correlated with number of genes or organism complexity
or size.
cysteine disulfide bonds (unique amino acid) Correct Answers -
Thiol (SH) that plays a role in the structure/shape of proteins.
-2 cysteine molecules undergo oxidation to form a cystine
disulfide bond (covalent bond between 2S is cysteine)
-In endoplasic reticulum lumen
5' pre-mRNA capping Correct Answers 1. Helps to protect
RNA from exonucleases
2. Completed before mRNA fully transcribed
A coiled coil Correct Answers Super secondary structure. (Two
helices wrap around to minimize e.g. exposure of hydrophobic
aa chain)
Amphipathic (different biochemical or biophysical properties on
different sides) alpha helix.
Coiled coils (strong structures that can give elasticity) are found
in alpha-keratin of skin, hair and also myosin motor proteins.
A number of Eukaryotic RNA polymerases needed Correct
Answers Each of these RNAPs is a multi-subunit protein. Each
RNAP is responsible for transcription of different RNAs. RNA
polymerase I, RNA polymerase II, RNA polymerase III.
Activator protein Correct Answers a regulatory protein that
binds to specific sites on DNA and stimulates transcription;
involved in positive control. Are in prokaryote and eukaryote
and help get out of abortive phase. It gives kiss to unleash RNA
creation.
Amino Acid Structure Correct Answers 1. Proteins are
composed of amino acids
2. The amino acid side-chain or R group is variable and
determines the type of amino acid
3. Major categories of amino acid: [acidic, basic, uncharged
polar, nonpolar] -> determined by particular side group
,4. All have NH2, carboxyl, and alpha carbon is where all other
atoms and groups are attached
Anti parallel beta sheet Correct Answers Protein chains running
in opposite directions.
1N and 1C terminus (one polypeptide chain) but 3 strands of
beta chain.
Backbone Correct Answers Backbone atoms N-C(a)-C-N are all
of the protein's atoms except for the side chain.
Bacterial DNA replication Correct Answers 1. Origin of
replication
2. Binding of initiator proteins
3. Unwinding by helicase
4. Binding of single-strand binding proteins
5. RNA primers made by primase
6. DNA polymerase
7. Sliding clamp holds polymerase onto DNA
8. Nick sealing by DNA ligase
Base Excision Repair (BER) Correct Answers
PROOFREADING: A DNA repair pathway that involves
excision of a damaged base by DNA glycosylase, followed by
cleavage of the DNA backbone adjacent to the site by an AP
endonuclease. Nick translation, DNA polymerization, and
ligation complete the repair. Takes out deaminated C and DNA
polymerase adds new nucleotide.
Base pairing Correct Answers 1. Holds the DNA double helix
together (Purine lines up with pyrimidine)
,2. A-T 2 H-bonds (how DNA lines up)
3. G-C 3 H-bonds (more bonds=stickier)
Bases Correct Answers Pyrimidine = 1 ring
(U C (see) T (the) pyramids) - longer name=shorter structures
Purine = 2 ring
(Purine is pure and has G(od) and A(ngles) short name=longer
structure).
Central Dogma (refined) Correct Answers DNA undergoes
transcription.
mRNA= messenger
tRNA=transfer (transport AA's, and for protein synthesis)
rRNA=part of ribosome
See slide 44.
Chaperone proteins Correct Answers assist in folding other
proteins
Chromatin Correct Answers Substance found in eukaryotic
chromosomes that consists of DNA tightly coiled around
histones
Chromatin packing and re-modeling Correct Answers
Chromatin remodeling complexes and histone modifying
enzymes are examples of proteins that can make changes in
chromatin structure and alter access to DNA for replication or
transcription. (Heterochromatin, Euchromatin)
Chromatin: levels of organization (really look at slides) Correct
Answers The net result is that each DNA molecule has been
, packaged into a mitotic chromosome that is 10,000 times shorter
than its extended length (packing/unpacking, requires ATP)
Euchromatin (before packed into nucleosome) and
heterochromatin (after packed into nucleosomes).
Chromatin: levels of organization Correct Answers -Short
region of DNA double helix
-"beads-on-a-string" form of chromatin (yellow is protein, red is
DNA and DNA is wrapped around nucleosome)
-Chromatin fiber of packed nucleosomes (30nm fiber)
-Chromatin fiber folded into loops
-Entire mitotic chromosome (centromere in middle)
Chromosome solution cont. Correct Answers In humans 23
pairs.
-Each chromosome (DNA wrapped around protein) contains a
single, long, linear DNA molecule and associated proteins called
chromatin (DNA+protein)
-Chromatin is tightly packaged, BUT the DNA must remain
accessible for transcription, replication, and repair.
-Chromatin is DYNAMIC (can make it more compact or less)
Comparing genome sizes Correct Answers Genome size is not
always correlated with number of genes or organism complexity
or size.
cysteine disulfide bonds (unique amino acid) Correct Answers -
Thiol (SH) that plays a role in the structure/shape of proteins.
-2 cysteine molecules undergo oxidation to form a cystine
disulfide bond (covalent bond between 2S is cysteine)
-In endoplasic reticulum lumen
