QBM final (exam 1) questions with verified
answers
DNA → RNA → protein Ans✓✓-Explain the central dogma of molecular biology.
RNA polymerase Ans✓✓-DNA can be transcribed into RNA by the enzyme
translated Ans✓✓-Following post-transcriptional processing, the resulting
messenger RNA (mRNA) can be read by the ribosome (a ribozyme, with both RNA
and protein components). This transcript is _____________ into protein, which
can perform various functions in the cell
DNA Ans✓✓-contains two strands of nucleic acids antiparallel to one another
5' → 3' Ans✓✓-Each strand consists of a negatively-charged sugar phosphate
backbone with __________ directionality
adenine with thymine, and guanine with cytosine Ans✓✓-Nucleotides within
DNA form base pairs:
allows for accurate repair of cytosine deaminations (loss of an -NH2 group
resulting from hydrolysis), and its methyl group may allow for better interactions
with proteins Ans✓✓-Thymine, which has an additional methyl group compared
to uracil, is important for DNA because it
hydrogen bonds and base stacking Ans✓✓-The DNA base pairs are held together
by both
,DNA polymerase Ans✓✓-DNA is copied by a protein called
S phase Ans✓✓-In humans, DNA replication occurs during the _____ phase of cell
division, and the process requires several different DNA polymerases
2' position on its ribose sugar (hence deoxyribose) Ans✓✓-DNA has a hydrogen (-
H) at the
RNA, or ribonucleic acid Ans✓✓-consists of single-stranded or double-strained
nucleic acids that can base pair, although irregularly, with DNA or RNA for short
stretches
uracil Ans✓✓-RNA consists of similar bases to DNA (both have adenine, guanine,
and cytosine), but RNA contains _________ instead of thymine
uracil Ans✓✓-capable of making nonstandard Watson-Crick base pairs, and it can
increase the diversity of base interactions and tertiary structures
hydroxyl (-OH) Ans✓✓-RNA has a much larger 2'___________ which gives it an
irregular shape in the double-stranded conformation
there are numerous RNases in cells and cell extracts that constantly degrade RNA,
and RNA's 2'-OH can perform a nucleophilic attack on the nearby phosphate
backbone, leading to self-cleavage Ans✓✓-RNA is also inherently less stable than
DNA because
enzyme Ans✓✓-Some RNA can form tertiary structures when the single-stranded
molecule base pairs with itself or another strand of RNA; after a short distance,
,the two strands usually branch off to form interactions with other nearby strands,
creating pockets, active sites, and domains
Therefore, RNA can act as an ___________ (called a ribozyme) and catalyze
reactions in the cell, although it is limited by the fact that it only uses four similar
bases to interact with substrates
The primary structure Ans✓✓-structure of a protein that consists of its amino
acid sequence
Secondary structure of protein Ans✓✓-elements like alpha-helices and beta-
sheets and several other motifs that can further fold into complex tertiary
structures
Tertiary structures Ans✓✓-Can perform specific functions as a result of their
shape
Proteins often have several domains connected to one another by the
polypeptide chain, and each domain has a specialized function
tertiary structure Ans✓✓-what is the structure of the protein p53, a tumor
suppressor that is activated upon DNA damage or cell stress, binding to DNA and
activating transcription of damage response genes?
quaternary structures Ans✓✓-Several single or multidomain proteins can interact
to form subunits of ___________________, which are separate polypeptide
chains that come together to form a macromolecular complex
, can be held together with weak interactions or disulfide bridges
Double-stranded
5'→3' directionality
Antiparallel
Base pairing (adenine with thymine, cytosine with guanine) via hydrogen bonding
Stabilized by base stacking and hydrogen bonds. Ans✓✓-Name three
characteristics of DNA.
DNA encodes RNA (transcription) which encodes proteins (translation). Ans✓✓-
What is the central dogma of molecular biology?
RNA is usually single-stranded, contains uracil instead of thymine, and has a 2'-
OH. Cytosine can be deaminated into uracil which would be impossible to repair
in RNA since uracil is a standard base, but DNA does not contain uracil and it can
therefore be easily repaired back to cytosine. Additionally, RNA has a 2'-OH which
causes an irregular double-stranded structure and allows for self-cleavage.
Ans✓✓-How does RNA differ from DNA? What is the significance of these
differences?
RNAs perform many cell functions, such as rRNA in the ribosome which
synthesizes proteins, tRNA which carries amino acids to the ribosome, mRNA
which encodes proteins, and miRNA which silences expression. Ans✓✓-What role
do RNAs play in the cell?
answers
DNA → RNA → protein Ans✓✓-Explain the central dogma of molecular biology.
RNA polymerase Ans✓✓-DNA can be transcribed into RNA by the enzyme
translated Ans✓✓-Following post-transcriptional processing, the resulting
messenger RNA (mRNA) can be read by the ribosome (a ribozyme, with both RNA
and protein components). This transcript is _____________ into protein, which
can perform various functions in the cell
DNA Ans✓✓-contains two strands of nucleic acids antiparallel to one another
5' → 3' Ans✓✓-Each strand consists of a negatively-charged sugar phosphate
backbone with __________ directionality
adenine with thymine, and guanine with cytosine Ans✓✓-Nucleotides within
DNA form base pairs:
allows for accurate repair of cytosine deaminations (loss of an -NH2 group
resulting from hydrolysis), and its methyl group may allow for better interactions
with proteins Ans✓✓-Thymine, which has an additional methyl group compared
to uracil, is important for DNA because it
hydrogen bonds and base stacking Ans✓✓-The DNA base pairs are held together
by both
,DNA polymerase Ans✓✓-DNA is copied by a protein called
S phase Ans✓✓-In humans, DNA replication occurs during the _____ phase of cell
division, and the process requires several different DNA polymerases
2' position on its ribose sugar (hence deoxyribose) Ans✓✓-DNA has a hydrogen (-
H) at the
RNA, or ribonucleic acid Ans✓✓-consists of single-stranded or double-strained
nucleic acids that can base pair, although irregularly, with DNA or RNA for short
stretches
uracil Ans✓✓-RNA consists of similar bases to DNA (both have adenine, guanine,
and cytosine), but RNA contains _________ instead of thymine
uracil Ans✓✓-capable of making nonstandard Watson-Crick base pairs, and it can
increase the diversity of base interactions and tertiary structures
hydroxyl (-OH) Ans✓✓-RNA has a much larger 2'___________ which gives it an
irregular shape in the double-stranded conformation
there are numerous RNases in cells and cell extracts that constantly degrade RNA,
and RNA's 2'-OH can perform a nucleophilic attack on the nearby phosphate
backbone, leading to self-cleavage Ans✓✓-RNA is also inherently less stable than
DNA because
enzyme Ans✓✓-Some RNA can form tertiary structures when the single-stranded
molecule base pairs with itself or another strand of RNA; after a short distance,
,the two strands usually branch off to form interactions with other nearby strands,
creating pockets, active sites, and domains
Therefore, RNA can act as an ___________ (called a ribozyme) and catalyze
reactions in the cell, although it is limited by the fact that it only uses four similar
bases to interact with substrates
The primary structure Ans✓✓-structure of a protein that consists of its amino
acid sequence
Secondary structure of protein Ans✓✓-elements like alpha-helices and beta-
sheets and several other motifs that can further fold into complex tertiary
structures
Tertiary structures Ans✓✓-Can perform specific functions as a result of their
shape
Proteins often have several domains connected to one another by the
polypeptide chain, and each domain has a specialized function
tertiary structure Ans✓✓-what is the structure of the protein p53, a tumor
suppressor that is activated upon DNA damage or cell stress, binding to DNA and
activating transcription of damage response genes?
quaternary structures Ans✓✓-Several single or multidomain proteins can interact
to form subunits of ___________________, which are separate polypeptide
chains that come together to form a macromolecular complex
, can be held together with weak interactions or disulfide bridges
Double-stranded
5'→3' directionality
Antiparallel
Base pairing (adenine with thymine, cytosine with guanine) via hydrogen bonding
Stabilized by base stacking and hydrogen bonds. Ans✓✓-Name three
characteristics of DNA.
DNA encodes RNA (transcription) which encodes proteins (translation). Ans✓✓-
What is the central dogma of molecular biology?
RNA is usually single-stranded, contains uracil instead of thymine, and has a 2'-
OH. Cytosine can be deaminated into uracil which would be impossible to repair
in RNA since uracil is a standard base, but DNA does not contain uracil and it can
therefore be easily repaired back to cytosine. Additionally, RNA has a 2'-OH which
causes an irregular double-stranded structure and allows for self-cleavage.
Ans✓✓-How does RNA differ from DNA? What is the significance of these
differences?
RNAs perform many cell functions, such as rRNA in the ribosome which
synthesizes proteins, tRNA which carries amino acids to the ribosome, mRNA
which encodes proteins, and miRNA which silences expression. Ans✓✓-What role
do RNAs play in the cell?
