Question

1a. List and describe 3 types of epigenetic inheritance.

1b. Describe the process of translation termination.

1c.What are the 3 main differences in how bacteria undergo translation?

Answer 1

1A. The 3 types of epigenetic inheritance.
1. DNA methylation
2. Histone modification
3. Non-coding RNA

1. The conversion of cytosine bases to 5-methylcytosine is catalysed by DNA methyltransferases.This mostly occurs in CpG islands. CpG island mostly present near to the transcription site so it control the gene expression of the gene.

2. Histone modification - Histone are +ve charge protein pack with -ve charge DNA. Histon emodification brings out number of biological process such as transcriptional activation/inactivation, chromosome packaging, and DNA damage/repair. The histone acetylation important role in gene expression. histone acetylation catalyse by histone acetyltransferases.

3. Non coding RNA palys important role in miRNA, SiRNA, piRNA and IncRNA. All this involved in control the gene expression.

1.B. When ribosome reaches the stop codon UAG, UAA, or UGA on mRNA the protein synthesis gets halted.
Then release factor binds to the ribosome and H2O hydrolyze the polypeptide chain in the tRNA. So, protein and the ribosome remove from the mRNA.

1.C.. In bacteria transcription and translation occurs simultaneously in the cytoplasm.
mRNA is a polycistronic so single start site will enough to produce more than one protein.
First amino acid is formylmethionine with end of the amino acid