Answer the questions below as completely and as thoroughly as possible and where

Question

Answer the questions below as completely and as thoroughly as possible and where appropriate include a specific example to illustrate. Answer the question in essay form (not as an outline or as bullets) using complete sentences. Cite sources of information you used to answer the questions or that support your answer.

24. Explain how genetic information is transferred from DNA to RNA to proteins. Include the terms DNA replication, transcription, translation, the principal events and enzymes. Use the following DNA molecule to illustrate each stage.

3' TAGCCACATTAGCCGATC5' Template strand used for transcription

5' ATCGGTGTAATCGGCTAG 3' Coding (“inactive” strand)

Note: Please read all the instructions especailly about providing a complete citation about where you got your answer from before answering #24.)

Explanation / Answer

DNA replication is the process of producing two identical replicas from one original DNA molecule. This biological process occurs in all living organisms and is the basis for biological inheritance. DNA is made up of two strands and each strand of the original DNA molecule serves as a template for the production of the complementary strand, a process referred to as semiconservative replication. Cellular proofreading and error-checking mechanisms ensure near perfect fidelity for DNA replication.

Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA(mRNA) by the enzyme RNA polymerase.Only one of the two DNA strands serve as a template for transcription. The antisense strand of DNA is read by RNA polymerase from the 3' end to the 5' end during transcription (3' 5'). The complementary RNA is created in the opposite direction, in the 5' 3' direction, matching the sequence of the sense strand with the exception of switching uracil for thymine.

Hence transcription for below strand-

3' TAGCCACATTAGCCGATC5'

would be 5' ATCGGTGTAATCGGCTAG 3'

In translation, messenger RNA (mRNA)—produced by transcription from DNA—is decoded by a ribosome to produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and performs its functions in the cell. The ribosome facilitates decoding by inducing the binding of complementarytRNA anticodon sequences to mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome. The entire process is a part of gene expression.

In brief, translation proceeds in four phases:

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