Exam 2 UC San Diego Biochem Test
Questions with Correct Verified
Answers 2025-2026 Updated.
gene - Answer a portion of DNA that is transcribed to express its encoded genetic information
or transform it into a more useful functional form (storage --> function)
What does the mRNA (RNA transcript) include? - Answer the mRNA includes everything
needed to dictate amino acid sequence
What do most RNA transcripts (mRNA) correspond to? - Answer Corresponds to a single
functional unit (e.g. polypeptide)
What does the launch of gene transcription require? - Answer requires non-transcribed
sections of DNA that help position the RNA polymerase before it launches its catalysis
What is the order of central dogma? - Answer DNA-(transcription)-> RNA-(translation) ->
protein
how do we access the information to begin transcription? - Answer modification of histones
with small chemical groups can significantly impact the structure of chromatin.
what is the significance of nucleosomes? - Answer they are packed really tightly so it makes it
hard for transcription but it is good for storage and transport
What residues may cause helices to fall apart? - Answer Glycine and Proline
Due to flexibility and sharp turn nature
residues within histones may gain what groups? - Answer acetyl, methyl, phosphoric, propinyl,
ADP-riboes, or ubiquitin
What is histone acetylation? - Answer turning genes on through covalent modifications at
lysine residues; leads to weaker interaction between DNA and histones because likely through
decreasing positive charge of lysine when interacting with the negatively charged DNA
, what is DNA methylation? - Answer turning off genes through covalent modifications of C
bases; addition of methyl groups to cytosine residues generate 5-methylcytosine
what is the significance of DNA methylation in gene expression? - Answer associated with
gene silencing (C bases next to G bases are most susceptible to this modification)
are all CpGs methylated? - Answer About 80% is methylated, but those near the start sites of
genes are unmethylated so transcription can start
How does DNA methylation silence genes? - Answer Recruits repressor proteins or inhibiting
binding of transcription factor proteins
Where is transcription initiated? - Answer promoter sites on the DNA template
What is the TATA box? - Answer A sequence on DNA that signals the beginning of a gene
What does transcription require? - Answer RNA polymerase and RNA nucleotides and
transcription factors (NO primer needed)
What is significance of transcription factors (TFs)? - Answer ensure genes are expressed at the
right place and at the right time
what is formed during transcription? - Answer a hybrid double helix forms
What is alternative splicing? - Answer mRNA processing events that lead to different
combinations of exons being spliced together
What is the 5' cap? - Answer methylated guanine nucleotide, helped recruit translation factors
to mRNAs to launch translation, makrks mRNA as self to avoid launching immune system
What is a Poly A Tail, and what does it do? - Answer Added to 3' end; increases stability and
lifespan of the RNA; allows export out of the nuclear so it may be translated in the cytoplasm
you find acetylation groups on a histone. the region of DNA is more likely...
Questions with Correct Verified
Answers 2025-2026 Updated.
gene - Answer a portion of DNA that is transcribed to express its encoded genetic information
or transform it into a more useful functional form (storage --> function)
What does the mRNA (RNA transcript) include? - Answer the mRNA includes everything
needed to dictate amino acid sequence
What do most RNA transcripts (mRNA) correspond to? - Answer Corresponds to a single
functional unit (e.g. polypeptide)
What does the launch of gene transcription require? - Answer requires non-transcribed
sections of DNA that help position the RNA polymerase before it launches its catalysis
What is the order of central dogma? - Answer DNA-(transcription)-> RNA-(translation) ->
protein
how do we access the information to begin transcription? - Answer modification of histones
with small chemical groups can significantly impact the structure of chromatin.
what is the significance of nucleosomes? - Answer they are packed really tightly so it makes it
hard for transcription but it is good for storage and transport
What residues may cause helices to fall apart? - Answer Glycine and Proline
Due to flexibility and sharp turn nature
residues within histones may gain what groups? - Answer acetyl, methyl, phosphoric, propinyl,
ADP-riboes, or ubiquitin
What is histone acetylation? - Answer turning genes on through covalent modifications at
lysine residues; leads to weaker interaction between DNA and histones because likely through
decreasing positive charge of lysine when interacting with the negatively charged DNA
, what is DNA methylation? - Answer turning off genes through covalent modifications of C
bases; addition of methyl groups to cytosine residues generate 5-methylcytosine
what is the significance of DNA methylation in gene expression? - Answer associated with
gene silencing (C bases next to G bases are most susceptible to this modification)
are all CpGs methylated? - Answer About 80% is methylated, but those near the start sites of
genes are unmethylated so transcription can start
How does DNA methylation silence genes? - Answer Recruits repressor proteins or inhibiting
binding of transcription factor proteins
Where is transcription initiated? - Answer promoter sites on the DNA template
What is the TATA box? - Answer A sequence on DNA that signals the beginning of a gene
What does transcription require? - Answer RNA polymerase and RNA nucleotides and
transcription factors (NO primer needed)
What is significance of transcription factors (TFs)? - Answer ensure genes are expressed at the
right place and at the right time
what is formed during transcription? - Answer a hybrid double helix forms
What is alternative splicing? - Answer mRNA processing events that lead to different
combinations of exons being spliced together
What is the 5' cap? - Answer methylated guanine nucleotide, helped recruit translation factors
to mRNAs to launch translation, makrks mRNA as self to avoid launching immune system
What is a Poly A Tail, and what does it do? - Answer Added to 3' end; increases stability and
lifespan of the RNA; allows export out of the nuclear so it may be translated in the cytoplasm
you find acetylation groups on a histone. the region of DNA is more likely...
