Session 7 - Lecture 1 Flashcards
2 - Gene expression overview
Gene expression
Genotype Phenotype
GENES on chromosomes in nucleus –message–> PROTEINS made in cytoplasm
DNA –transcription–> mRNA –translation–> protein
{DNA makes RNA molecule called messenger RNA (message) which makes protein}
3 - Gene expression
Gene expression
DNA –> mRNA –> protein
transcription translation
“copying the code” “changing the language”
{DNA to MRNA copies the code aka transcribes, keeps the same language nucleic acid language. mRNA needs to TRANSLATE message into protein - changing the language}
4 - Gene expression location and function
Gene expression
Nucleus DNA –> RNA transcription
Cytoplasm
–> mRNA Ribosome Protein chain translation
{DNA ds, RNA ss in nucleus. RNA EXPORTED out of NUCLEAR PORE to mRNA in cytoplasm, ribosome attached to make protein. TX in nucleus, TRANS in CYTOPLASM.
Every cell in your body has all the DNA your body contain, but not every cell needs all that info - so genes need to be expressed diff times. But we need all these genes so that they can b passed onto offspring. So gene expression v important and regulated in eukaryotes}
5 - What is a gene?
What is a gene?
- stretch of DNA, chromosomal locus
- ‘recipe’ for protein (code + regulation)
- 2 x 25,000 alleles per cell
- ‘unit of inheritance’
- ‘unit of transcription’
{1. somewhere on chromosome there is a gene
- code is actually made into protein but also the regulation of protein - regulatory sequences part of gene - important for when and how much gene expression takes place.
- inherit genes from parents - 2 copies so 2 alleles in every cell of body/2 alleles of every gene.
- from parents
- also UOT in gene expression.
img shows ONLY 2% actually codes for genes - 98% non-coding DNA}
6 - How does DNA make a protein?
Gene expression
DNA ____transcription initiation___________transcription termination___
mRNA 5’___translation initiation____translation termination___ 3’
protein N===C
{dsDNA so no need for 5’ or 3’ - signals that start and end tx.
mRNA ss so need direction. This is a certain length due to tx signals. But on mRNA itself also has translation signals.
proteins made from N-C direction and has signals}
7 - What is a gene?
What is a gene?
DNA ____transcription initiation___________transcription termination___
transcription
mRNA 5’___translation initiation____translation termination___ 3’
translation
protein N===C
8 - What do you need for gene expression?
Gene expression
Making a polynucleotide or polypeptide
- needs an enzyme
- needs activated substrates
- needs a template
- 3-stage process:
initiation
elongation
termination
{DNA to make polyNT tx, RNA to make polypeptide trans.
needs enzyme, substrate, template to make reaction work. I E T - start, keep it going, stop.}
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