BIO 1002B: Cycle 7 Outcomes And
Cycle 9 Test Questions and Correct
Answers.
Compare and contrast prokaryotic vs eukaryotic transcription and translation. - Answer In
prokaryotes (cells that do not have a nucleus) both transcription and translation take place in
the cytoplasm of the cell.
In eukaryotes (cells that have a nucleus) transcription takes place in the nucleus while
translation takes place in the cytoplasm
Make your "complementary base pairing" list of molecules; complete the chart to understand
how signals in the DNA are "understood" in the cell and the molecule(s) associated with that
recognition. - Answer DNA - Self (alpha helix), DNA (DNA replication), mRNA, rRNA, tRNA,
snRNA (all during transcription)
mRNA - Self, DNA (transcription), snRNA (splicing of pre-mRNA in eukaryotes), rRNA (SD box-
translation initiation in prokaryotes), tRNA (translation)
tRNA - Self, DNA (transcription), mRNA (SD box-translation initiation in prokaryotes)
rRNA - Self, DNA (transcription), mRNA (translation)
snRNA - Self, DNA (transcription), pre-mRNA (splicing in eukaryotes).
Proteins - No complementary base pairing because they don't have nucleotides.
Understand the central dogma and why it is not "entirely correct" in that many RNA molecules
do not get converted to protein because they function as RNA. - Answer The central dogma
is that the process that happens in cells is DNA -> RNA --> Protein
However, this is not "completely right" because this is only true for protein coding genes. Some
genes code for functional rNA such as tRNA for translation or rRNA for ribosomes to attach too
mRNA in prokaryotes. So for them, it is just DNA to RNA.
Structure of ribosomes (rRNA + protein). rRNA plays the catalytic role, not the proteins. -
Answer Ribosomes are complexes with rRNA and proteins. There are two main functional
, units in the ribosome, the large and small ribosomal. The rRNA plays a catalytic role by
complementary base pairing with the mRNA to direct the ribosome to where translation should
begin. When the start codon is found , the large subunit attaches, and translation begins.
Know that all types of RNA have secondary structure. - Answer All DNA that codes for RNA
has regions of inverted repeats allowing the RNA to complementary base pair with itself and
create a secondary (functional) structure
Know which strand serves as template for transcription. - Answer The 3' to 5' strand is the
template (non-coding, antisense) strand.
Know the sequence of the start and stop codons. - Answer AUG (ATG) - methionine start
codon.
UAA (ATT), UAG (ATC), UGA (ACT) - stop codons
Understand how tRNA works. - Answer 1. Bring AA to the ribosome
2. Ribosomes have three slots for tRNAs
3. tRNA matches an mRNA codon with the AA it codes for
4. Each tRNA contains an anticodon; this can bind to one or very few mRNA codons
5. tRNA molecule also carries an amino acid; the one encoded by the codons that the tRNA
binds
6. tRNAs bind to the codon inside of the ribosome, where they deliver AA for addition to the
protein chain
7. How does the right AA get linked to the right tRNA; enzymes fueled by ATP
tRNA has an anticodon region and a region that binds to a specific
amino acid. In the ribosome, the tRNA complementary base pairs to the complementary codon
and adds its amino acid to the growing polypeptide chain
Know the basic steps in translation. Note that translation initiation is different in prokaryotes vs
eukaryotes but the rest of translation is very similar. - Answer In prokaryotes, the ribosome's
complementary base pairs with the SD box in mRNA and searches for the start codon from
there. In eukaryotes, the ribosome attaches to the 5' cap and begins scanning for the start
codon. The tRNA containing methionine then connects in both cases, allowing translation to
begin. The ribosome moves as the next tRNA complementary base couples with the next codon
and adds its amino acid to the chain. The tRNA that just lost an amino acid can now escape.
This process is repeated until the ribosome reaches the stop codon. Then, a release factor binds
(not comp base pairs) and causes the polypeptide to be released, and the ribosome to
disassemble.
Cycle 9 Test Questions and Correct
Answers.
Compare and contrast prokaryotic vs eukaryotic transcription and translation. - Answer In
prokaryotes (cells that do not have a nucleus) both transcription and translation take place in
the cytoplasm of the cell.
In eukaryotes (cells that have a nucleus) transcription takes place in the nucleus while
translation takes place in the cytoplasm
Make your "complementary base pairing" list of molecules; complete the chart to understand
how signals in the DNA are "understood" in the cell and the molecule(s) associated with that
recognition. - Answer DNA - Self (alpha helix), DNA (DNA replication), mRNA, rRNA, tRNA,
snRNA (all during transcription)
mRNA - Self, DNA (transcription), snRNA (splicing of pre-mRNA in eukaryotes), rRNA (SD box-
translation initiation in prokaryotes), tRNA (translation)
tRNA - Self, DNA (transcription), mRNA (SD box-translation initiation in prokaryotes)
rRNA - Self, DNA (transcription), mRNA (translation)
snRNA - Self, DNA (transcription), pre-mRNA (splicing in eukaryotes).
Proteins - No complementary base pairing because they don't have nucleotides.
Understand the central dogma and why it is not "entirely correct" in that many RNA molecules
do not get converted to protein because they function as RNA. - Answer The central dogma
is that the process that happens in cells is DNA -> RNA --> Protein
However, this is not "completely right" because this is only true for protein coding genes. Some
genes code for functional rNA such as tRNA for translation or rRNA for ribosomes to attach too
mRNA in prokaryotes. So for them, it is just DNA to RNA.
Structure of ribosomes (rRNA + protein). rRNA plays the catalytic role, not the proteins. -
Answer Ribosomes are complexes with rRNA and proteins. There are two main functional
, units in the ribosome, the large and small ribosomal. The rRNA plays a catalytic role by
complementary base pairing with the mRNA to direct the ribosome to where translation should
begin. When the start codon is found , the large subunit attaches, and translation begins.
Know that all types of RNA have secondary structure. - Answer All DNA that codes for RNA
has regions of inverted repeats allowing the RNA to complementary base pair with itself and
create a secondary (functional) structure
Know which strand serves as template for transcription. - Answer The 3' to 5' strand is the
template (non-coding, antisense) strand.
Know the sequence of the start and stop codons. - Answer AUG (ATG) - methionine start
codon.
UAA (ATT), UAG (ATC), UGA (ACT) - stop codons
Understand how tRNA works. - Answer 1. Bring AA to the ribosome
2. Ribosomes have three slots for tRNAs
3. tRNA matches an mRNA codon with the AA it codes for
4. Each tRNA contains an anticodon; this can bind to one or very few mRNA codons
5. tRNA molecule also carries an amino acid; the one encoded by the codons that the tRNA
binds
6. tRNAs bind to the codon inside of the ribosome, where they deliver AA for addition to the
protein chain
7. How does the right AA get linked to the right tRNA; enzymes fueled by ATP
tRNA has an anticodon region and a region that binds to a specific
amino acid. In the ribosome, the tRNA complementary base pairs to the complementary codon
and adds its amino acid to the growing polypeptide chain
Know the basic steps in translation. Note that translation initiation is different in prokaryotes vs
eukaryotes but the rest of translation is very similar. - Answer In prokaryotes, the ribosome's
complementary base pairs with the SD box in mRNA and searches for the start codon from
there. In eukaryotes, the ribosome attaches to the 5' cap and begins scanning for the start
codon. The tRNA containing methionine then connects in both cases, allowing translation to
begin. The ribosome moves as the next tRNA complementary base couples with the next codon
and adds its amino acid to the chain. The tRNA that just lost an amino acid can now escape.
This process is repeated until the ribosome reaches the stop codon. Then, a release factor binds
(not comp base pairs) and causes the polypeptide to be released, and the ribosome to
disassemble.
