MBG 1000 Chapter Notes - Chapter 11: Acetyl Group, Hemoglobin, Fetus

• School: University of Guelph
• Department: Molecular Biology and Genetics
• Course: MBG 1000
• Professor: Christine Schisler

Document Summary

Gene expression patterns change over time and in different cell types. The subunit composition of hemoglobin changes in the embryo, fetus and after birth. As a pancreas forms, progenitor cells diverge from shared stem cells and their daughter cells specialize. Proteomics tracks all of the proteins in a cell, tissue, organ, or organism under specific conditions. Acetyl, phosphate, and methyl groups bind to histone proteins, controlling transcription. Acetyl and phosphate groups turn on transcription; methyl groups turn it off. Micrornas bind to the control regions of specific mrnas, blocking translation. Only a tiny proportion of the genome encodes protein, yet the number of proteins greatly outnumbers known protein-encoding genes. Alternate splicing, introns that encode protein and cutting a precursor protein maximize the number of proteins that dna encodes. Most of the human genome does not encode protein. Most of the genome encodes many types of rna as well as viral sequences, introns, promoters and other control sequences and repeats.