DNA Structure and Function
What are the four nitrogen bases in DNA? Full names, please
Adenine (A), Thymine (T), Cytosine (C), Guanine (G
What enzyme is responsible for unzipping the DNA strands?
Helicase
What is transcription?
Making mRNA from DNA using RNA Polymerase
What is a mutation?
A change in the DNA sequence
What sugar is found in RNA but not in DNA?
Ribose
Why is complementary base pairing important in DNA structure?
It makes sure that when DNA is replicated, it is the same every time since A-T, and C-G
How does the semi-conservative nature of replication prevent major errors?
Each new DNA molecule retains one original strand, reducing copying mistakes.
Why does transcription need to occur before translation?
DNA cannot leave the nucleus, so an mRNA copy is needed to carry instructions to the ribosome.
Why do some mutations have no effect on an organism?
a silent mutation where the amino acid remains the same
How does RNA help DNA carry out its function?
RNA transcribes DNA’s instructions and translates them into proteins.
What is Chargraff's Rule?
A=T, G=C
Predict what would happen if DNA Ligase failed to work properly.
There would be missing nucleotides, or holes in the strands of DNA
Predict what would happen if a mutation caused a stop codon to appear in the middle of an mRNA sequence.
Translation would stop early
Given the following Sequence, identify the type of mutation and what the result is
Original: TAC ATG GGG CGT TAT AGT
Mutation:TAC ATG GGC GTT ATA GT
Deletion, and frameshift
Predict what would happen if RNA polymerase stopped working.
No mRNA would be made, preventing protein synthesis and leading to cell malfunction or death.
What are the 3 parts of a nucleotide?
Phosphate, Sugar, Base
Why must a Cell copy its DNA
So at the end of mitosis, each cell has a complete set of DNA
What are the functions of tRNA, mRNA, and rRNA?
mRNA carries instructions, tRNA brings amino acids, and rRNA helps assemble proteins in ribosomes
Which would have more impact on the DNA? A substitution mutation or a frameshift mutation?
Point mutations change a single base, which may or may not affect the protein, while frameshift mutations shift the entire reading frame, causing major changes.
What is the difference in the function of DNA and RNA?
DNA stores genetic information, while RNA transmits and translates it to create proteins.
You have a DNA sequence that is 30%C, what amount of A, T, G is there?
G=30%
A= 20%
T= 20%
A scientist alters the structure of DNA polymerase, preventing it from proofreading. What long-term effects might this have on an organism?
There would be increased chance for mutations to occur
If a mutation caused all ribosomes in a cell to stop functioning, what would happen to the organism over time?
No proteins would be made, leading to cell death and eventually the organism's death.
If a mutation in a population provides an advantage, how might it spread over generations?
Natural selection would favor individuals with the mutation, increasing its frequency in the population over time.
Predict what would happen if RNA Polymerase had a mutation that allowed it to use DNA nucleotides instead of RNA nucleotides. What might happen in the translation process as a result?
There might be Thymine in the mRNA strand, which would not call for a tRNA, which would stop protein synthesis.