Question

Briefly describe different excitatory or inhibitory regulatory mechanisms at or due to the following processes: a) DNA organization/initiation of transcription; b) Transcriptional regulation; c) splicing d) mRNA stability/degradation; e) translational initiation; f) post-translational modifications.

Answer 1

different excitatory or inhibitory regulatory mechanisms at

a) DNA organization/initiation of transcription

1. enzyme RNA polymerase binds to a promoter region of a gene.
2. DNA gets unwind and enzyme ''read'' the bases in DNA strands.
3. enzyme make a complementary strand of mRNA.

b) Transcriptional regulation

1. regulation of the conversion of DNA to RNA
2. this allows to respond to a variety of intracellular and extracellular signals

c) splicing

1. splicing is a process of removal of introns of genes from pre-mRNA
2. these introns are non coding gene sequences
3. sliced sequences joins the protein-coding sequences
4. this allows the translation process.

d) mRNA stability/degradation

1. occurs when change in response to developmental or environmental stimuli as well as environmental stresses.

e) translational initiation

1. eukaryotic initiation factors are involved
2. this process is a complex process in which eukaryotic initiation factors allows initiator tRNA, ribosomal subunits(40S, and 60S ) to assembled into an 80S ribosome.

f) post-translational modifications

1. after translation i.e. mRNA translate into long polypeptide chain of protein, proteins undergo enzymatic modification
2. this results into formation of mature protein product.