1A Flashcards
What is genetics
Study:
1. Heredity
2. Variation
In ind. cells and pop
Gene?
Unit of heredity and variation
Gene role
DNA sequence that makes RNA and protein
Allele?
Varient form of gene caused by DNA sequence
Genotype
Gene inherited by organism
Phenotype
Visible traits (behaviour, illness/etc.)
Genome
Entire DNA sequence
Where are genes
On chromosomes and they are part of genome that encode for RNA and protein
Gene expression
Turn on gene to make RNA and protein (coding gene)
Protein expression
Type and abundance of protein in cell
Why do proteins determine phenotype
They control every rxn in cell
Enzymes
Catalyze synthesis and transformation of all biomolecules
Structuralproteins
Maintain cell shape
Signaling protein
Hormone and receptor
What causes phenotypic variation
1.diff allele (variation in gene sequence=> change in a.a. Sequence of proteins) (type of colour)
2. Differential regulation of gene and protein expression (how much colour is expressed)
Uses of molecular genetics
1.human health
Forensics
Agriculture
Environnement
Evolutionary bio
3 classical experiments that established DNA as hereditary molecule
- Griffith
2.Avery, Macleod and McCarthy - Hershey and Chase
Griffith accomplishement
Found smt that could genetically transform streptococcus pneumonia
Avery Macleod and McCarthy accomplishment
Identified DNA as molecule that transforms rough pneumonia (R) and non virulent=> virulent form (S)
Hershey and Chase accomplishment
Final evidence that DNA is hereditary molecule
What is streptococcus pneumonia and what are the two types
-bacterial pathogen that causes pneumonia
1. Smooth strain (S)
2. Rough strain (R)
Smooth strain (S)?
Bacteria surrounded by polysaccharide capsule= protect S strain from immune system… virulent
Rough strain (R)?
No polysaccharide capsule (weak so can’t attack immune system)… non-virulent
Griffith experiment process
(Transforming principle)
1. Mouse died of pneumonia from S
2. Mouse unaffected by R
3. Mouse unaffected by heat killed S
4. Mouse died of pneumonia from heat killed S and R
Griffith conclusion
Transforming principle: molecules released when S killed=> transform living R cell to S form
(Permanent and heritable)
Avery Macleod and McCarthy question
Is transforming principle: protein, DNA or RNA
AMM experiment process
Cell extract/cytoplasm of heat killed S cells that have protein RNA and DNA
- RNAse.. RNA dead but R=>S
- Protease… Protein dead but R=>S
- DNAse… DNA dead and R no change
Avery Macleod and McCarthy conclusion
DNA os transforming principle cause when DNA was killed by DNAse R did not become virulent
2 types of life cycles of virus
- Lytic cycle (virulent and reproduction of virus=host cell rupture/lysis)
- Lysogenic cycle (replicate viral genome-latent/hidden form)
During the lytic cycle does viral DNA replication in bacterial chromosome
NOOO separately
WHat can lysogeny do that lytic cycle cant
Can switch to lytic if viral DNA is released from bacteria chromosome
Steps of lytic pathway
- Infection
- Circular action of viral DNA
3.replicate (viral DNA, RNA , protein)… b. Chromosome degradation - Assemble into progeny/viral particles
- Celllysis and mature phage release
Lysogeny process
- Infection
- Circularization of viral DNA
- Viral DNA insert into bacterial chromosome (recombination)
4.pro phage replicates (viral gene inactive) - Pro phage inherited in bacterial daughter cell
Is Hershey and chase lytic or lysogenic experiment
Lytic
Hershey and chase experiment process
2 bacteriophages…
1. Radioactive isotopes 32P (DNA),and 35S (protein)
2. Infection of E.coli
3. Separate attached bacteriophage and e.coli through centrifugation
4. Determine how much of each is there
Hershey and Chase conclusion
32P/DNA is heritable cause detached bacteriophage had 32P
35S/protein is NOT heritable cause not found in d.b.
