Question

in a eukaryotic cell, the hydrophilic ligand CUE binds the enzyme-linked receptor CUE receptor. Describe a hypothetical but realistic signal transduction cascade, that eventually leads to the transcription of the GRAD gene. The GRAD protein is secreted by the cell. Describe the critical steps in gene transcription, RNA processing and in translation, and which structures and organelles are involved.

Answer 1

Solution:

Critical steps in gene transcription.

1.Initiation- it occurs when the enzyme RNA polymerase binds to gene called promoter.

2.Elongation-RNA polymerase moves with template strand and synthesising an mRNA molecule.

3.Termination-Involving the addition of additional adenine nucleotides at the 3' of the RNA transcript.

Steps in Rna processing.

• Pre-mRNA Processing. The eukaryotic pre-mRNA undergoes extensive processing before it is ready to be translated. ...
• 5′ Capping.
• 3′ Poly-A Tail.
• Pre-mRNA Splicing.
• Discovery of Introns.
• Intron Processing.

Steps in translation.

Initiation-The ribosome assembles around the target mRNA.

Elongation- The tRNA transfers an amino acid to the tRNA corresponding to the next codon.

Termination- When a stop codon is reached, the ribosome releases the polypeptide.

Organelles and structures involved are RNA polymerase,nucleus, ribosome and DNA