Vocabulary
What is a gene?
Answer: a segment of DNA that encodes for a functional molecule.
Where is transcription located?
Answer: nucleus.
What is anticodons?
Answer: complementary to codons in mRNA.
Which two nitrogenous bases are purines? Pyrimidines?
Answer: Purines-A, G. Pyrimidines-C,T.
In RNA, U replaces with which nitrogenous base?
Answer: T.
What is frameshift mutation?
Answer: insertions or deletions of bases in DNA.
True or False: the mRNA is copied from the antisense strand.
Answer: True.
What is the function of rRNA?
Answer: part of a ribosome. Catalyzes the formation of peptide bonds between amino acids when synthesizing a polypeptide.
What is chargaff’s rule?
Answer: in any given sample of double stranded DNA, A=T, G=C.
If the DNA sequence is ATG, what is the mRNA sequence?
Answer: UAC.
What is intron?
Answer: it is the non doing sequences or the intervening region. They separates exons code for different domains.
What is the function of mRNA?
Answer: carries an RNA copy of a DNA sequence to the site of protein synthesis at the ribosome.
What is the function of mRNA?
Answer: It carries individual amino acids to the ribosome for polypeptide assembly.
What is the bond between nucleotide?
Answer: Phosphodiester bond.
When we want to find the corresponding amino acids, are we using the codon from tRNA or mRNA?
Answer: mRNA.
What is spontaneous mutation?
Answer: mutation occurs with no outside influence, include replication errors, errors in meiosis, and random chemical changes of nitrogenous base.
What is the three phases of transcription?
Answer: initiation, elongation, termination.
What are the common start codon and stop codons?
Answer: Start codon—AUG (initiation signal for translation). Stop codon—UAA, UAG, UGA (stop translation and polypeptide is released).
What is the difference between DNA polymerase I, II, and III?
Answer: DNA polymerase I replace the RNA primer at the end with nucleotides. DNA polymerase II proofread to find out some mistakes. DNA polymerase III do most of the work; it adds nucleotide to make a new strand of DNA.
When DNA sequence is GCGATATCG, what is the mRNA sequence and tRNA sequence?
Answer: mRNA squence-CGCUAUAGC. tRNA sequence-GCGAUAUCG.
What is a promoter?
Answer: Promoter is a particular sequence of DNA that RNA polymerase recognizes.
How did the transcript falls away?
Answer: the transcript falls away from the DNA template and RNA polymerase; for others, a helper protein pulls it away.
Explain the three sites of ribosome.
Answer:
-E site: ejects the uncharged tRNA to go and fetch another amino acid.
-P site: passes the amino acid and forms a peptide bond. The mRNA will slide across by one codon and a peptide bond will be formed between the newly brought amino acid and the last amino acid added at the P site.
-A site: accepts a tRNA with the amino acid it’s coded for.
How do cell adds nucleotide to the lagging strand?
Answer: When creating a new strand pairing with lagging strand, it’s discontinuous. Primase is really important; it requires many RNA primer in order to start a new Okazaki fragment.
How many codon combinations are there?
Answer: 64.