DNA Structure and Function
What are the two types of nitrogenous bases in DNA?
Purines and pyrimidines.
What enzyme is responsible for unzipping the DNA strands during replication?
Helicase.
What is the primary difference between RNA and DNA in terms of nitrogenous bases?
RNA contains uracil instead of thymine.
Where does translation occur within the cell?
The ribosome.
What is the central dogma of molecular biology?
DNA → RNA → Protein.
Name the four nitrogenous bases found in DNA.
Adenine, Thymine, Cytosine, Guanine.
During DNA replication, what is the function of DNA polymerase?
To add complementary nucleotides to the growing DNA strand.
What is the function of mRNA in transcription?
To carry the genetic code from DNA to the ribosome.
What molecule brings amino acids to the ribosome?
tRNA (transfer RNA).
What is a point mutation?
A mutation that affects a single nucleotide in the DNA sequence.
What type of bond holds the two DNA strands together?
Hydrogen bonds.
What is meant by “semi-conservative” replication?
Each new DNA molecule consists of one old strand and one new strand.
What enzyme is responsible for synthesizing mRNA during transcription?
RNA polymerase.
What are the three stages of translation?
Initiation, elongation, and termination
What is a frameshift mutation, and what is its potential effect?
A mutation caused by insertions or deletions of nucleotides, which can shift the reading frame and alter the entire amino acid sequence downstream.
Where in the cell is DNA primarily located?
The nucleus.
What is the name of the short segments synthesized on the lagging strand?
Okazaki fragments.
What is a promoter?
A DNA sequence where RNA polymerase binds to initiate transcription.
What is a codon, and what does it code for?
A sequence of three nucleotides in mRNA that codes for an amino acid.
How do silent mutations differ from missense mutations?
Silent mutations do not change the amino acid sequence, while missense mutations result in a different amino acid.
What is the shape of the DNA molecule?
What is the shape of the DNA molecule?
Which enzyme joins the Okazaki fragments together?
DNA ligase.
In which part of the cell does transcription occur?
The nucleus.
What is the start codon, and which amino acid does it code for?
AUG, which codes for methionine.
What is the role of the central dogma?
It describes the flow of genetic information from DNA to RNA to proteins.