a.
Replication - nucleus
b.
Transcription – nucleus
c.
Translation – ribosomes
11. What happens during the following events?
Transcription
Translation
1.
Initiation
RNA polymerase, the enzyme
responsible for transcription, binds to a specific region of DNA known as the promoter.
This signals the beginning of the gene to be transcribed.
The small ribosomal subunit binds to the mRNA at the start codon (usually AUG), and the initiator tRNA carrying the amino acid methionine binds to the start codon. The large ribosomal subunit then joins, forming a functional ribosome.
2.
Elongation
The RNA polymerase moves along the DNA template strand, synthesizing an RNA molecule by adding complementary nucleotides. The RNA sequence is complementary to the DNA template strand, with uracil (U) replacing thymine (T) in the RNA molecule.
The ribosome moves along the mRNA, and transfer RNA
(tRNA) molecules bring amino acids to the ribosome in accordance with the mRNA codons. The ribosome
facilitates the formation of peptide bonds between amino
acids, creating a polypeptide chain.
3.
Termination
Transcription concludes when
the RNA polymerase reaches a termination sequence in the DNA. This signals the end of the gene, and the RNA polymerase releases the newly synthesized RNA molecule.
Translation continues until a stop codon (UAA, UAG, or UGA) is reached on the mRNA. At this point, a release factor binds to the stop codon, causing the ribosome to release the completed polypeptide chain.
12: Give the function of the following enzymes and mention the process they are a part of:
Enzyme
Process
Function
RNA polymerase
Transcription
Responsible for catalyzing the synthesis of RNA from a DNA template.
DNA polymerase III
Replication
It synthesizes the new complementary DNA
strand during the elongation phase of DNA replication
Ligase
Replication
catalyze the formation of covalent bonds between adjacent DNA fragments, sealing gaps in the DNA backbone.
