Chapter 11: Gene expression and epigenetics

Transcriptome

collection of mRNA molecules in a cell

Single-cell transcriptomics

biotechnology used to identify all individual mRNAs in a cell at a given time n circumstance

Chromatin remodelling

adding/removing chemical groups to histones

• stop/start gene expression

microRNAs

binds to certain mRNAs to block their translation into protein

• 21-22 bases long

Acetyl and phosphate groups

enables gene expression

Methyl groups

STOPS gene expression

Microproteins

Fit into spaces of large proteins, affecting their folding and function

Gene expression as pancreas develops

Stem cell divides into a progenitor cell, forming endocrine and exocrine parts

Proteomics

Biotechnology measuring levels of proteins in many places and conditions

Alternative splicing

process where exons of a pre-mRNA are reconnected in multiple combinations

• allows a single gene to code for multiple distinct proteins.

number of protein encoding genes in human genome vs how many end up produced

20,000 GENES create 100,000 PROTEINS

Post-translational cleavage

The process where a single large precursor protein is cut by enzymes into smaller, independent, functional proteins

Post-translational modifications

Chemical changes made to a protein after its synthesis altering its structure, function, or cellular destination.

evolutionary benefit to maximizing genetic info

keeps DNA database lightweight while allowing body to meet complex biological demands

Glycoprotein

A carbohydrate

• added as a post-translational modification

• chemically bonded to protein to change their function

Lipoprotein

Fat.

• added as a post-translational modification

• chemically bonded to protein to change their function

Introns vs Exons

In: discarded during splicing. does not code for protein

• may act as exons to expand protein diversity

Ex: Coding sequences of DNA/RNA that are expressed and kept in the final mature mRNA.