Q1CC The best estimate is that the hu... [FREE SOLUTION]

Chapter 21: Q1CC (page 440)

The best estimate is that the human genome contains fewer than 21,000 genes. However, there is evidence that human cells produce many more than 21,000 different polypeptides. What processes might account for this discrepancy?

Short Answer

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The process that causes the discrepancy, such as fewer genes, is described by the alternative splicing of RNA transcripts from a gene. However, a higher number of polypeptides are described by the post-translational processing of polypeptides

Step by step solution

Genes and polypeptides

A gene is defined as an elementary physical as well as a functional unit of heredity.Thefunctional yields of most recognized genes are described as proteins.These are also acknowledged as polypeptides.

It is acknowledged that numerous proteins possessonly one polypeptide.However, few proteins are composed ofnumerous polypeptides.

Alternative splicing of RNA transcripts from a gene

Alternative splicing works byjoining or skipping sections of exons as well as noncoding sections inside a pre-mRNA transcript.This results in theformation of multiple protein isoformsthat are programmed by a distinct gene.

Post-translational processing of polypeptides

The post-translational modification process describes the biochemical variations that occur after the construction of a protein.

This process comprisescovalent processing measuresthat alter the features of a protein by theaction of proteolytic cleavage and by adding diverse groups like acetyl, methyl, and others. So, both these processes exhibit their role in explaining the discrepancy in terms of genes and polypeptides.