2A Flashcards
Central dogma
Info flow DNA->protein,why? Convert genotype-> phenotype
I.e.: transcription and translation
Where do transcription and translation occurs in prokaryotes
Cytoplasm
Where do transcription and translation occurs in eukaryotes
Transcription-nucleus
Translation-cytoplasm
Replication…___->____
DNA->DNA, DNA poly
Transcription…___->____
DNA->RNA using RNA poly
Translation…___->___
RNA->protein using ribosome
Rev. Transcription… ___->____
RNA->DNA,rev. Transcriptase
Beagle and Tatum hypothesis
Gene encode enzyme that works at each step in biochemical pathway to make essential nutrient
In the one gene one enzyme protein hypothesis what happens if you mutate a gene encoding an enzyme
A block in the metabolic pathway and organism can no longer make needed nutrient (autotroph/mutant)
Isolating ___ auxotrophic mutant conclusion
If after arrow and added then it can grow
If before arrow and added then can’t grow
2 types of RNA encoded by genes
- Coding RNA (mRNA)
- Non coding RNA (tRNA, rRNA, snRNA,microRNA)
Coding RNA
Code for protein/polypeptide
Noncoding RNA
Not code for protein
Genetic code??
Nucleotide info to a.a.sequence (in 4 nucleotide bases-ATGC for DNA OR RNA AUGC)
DNA has ____ letter code
Three-> triplet so 64 comb. (4^3)
RNA has ___ letter code
Three-> codon (messenger RNA)64 combo. (4^3)
Is genetic code universal
YES… same in prokaryote,eukaryote, virus
What does universal genetic code enable
Allow foreign genes to be transferred and expressed in diff host organisms
Why is dyed protein used in genetic code testing
See where it is and temporal expression of the protein
During transcription how many RNA from DNA template strand
1,
If template strand is 3->5 then. 1. RNA is in ___->____. 2. Nontemplate is ____->_____
- 5->3. 2. 5->3
Is the nontemplate strand used in transcription
NOOO… coding strand and transcription only occurs for template in 5’->3’
What happens if wrong DNA strand is read during transcription
Nonfunctional protein sequence is produced
What is shown on the coding strand for chromosomal maps
Genes are shown on nontemplate strand
Where is rev. Transcriptase found
Viruses with RNA genomes (retrovirus)
Lysogeny and rev. Transcription… how are they related???
Viral RNA converted into viral DNA to integrate into host chromosome
HIV life cycle (process)
- Binding- HIV bind to surface of host cell
- Fusion-virus fuse with cell membrane of host cell (enter cell)
- Rev. Transcription-inside cell, RNA->DNA (enzyme: reverse transcriptase)
- Integration (HIV DNA integrates into host DNA, enzyme-integrase)
- Replication-HIV makes long chain of HIV protein
- Assembly-HIV protein+RNA (both on surface of cell))… assemble into immature HIV
- Budding-immature HIV pushed out of cell (protease)… became mature and virulent
3 enzymes in HIV life cycle
- Reverse transcriptase-convert RNA->DNA
2.Integrase- transport new DNA into nucleus… through pore… cut host DNA and insert viral DNA into genome
3.protease-breakup polyprotein chain and allow viral cell to mature
Life cycle of SARS-CoV2 process
1.binding-S protein to ACE2 receptor
2.viralenvelope and host membrane fuse (enter host cell)
3. Viral RNA enter cell
4. Translation (protein->RNA)
5. RNA replication
6. Endoplasmic ret. Transformed to bubble
7. Genomic transcription and sub genomic transcription
8. Translated structural protein integrate into ER golgi
9. RNA +N (combine in neocapsid)
10. Membrane protein envelop neocapsid= make vision and move through golgi
11. Exocytosis (leave cell)
Is SARS CoV2 lysogenic
NO
What are the 4 structural proteins in SARS CoV2
Spike, envelope, membrane, nucleocapsin
Where are ACE2 receptors expressed
Alveolar lung, heart, intestine
In SARS CoV2 can RNA be made from scratch??
NO, RNA dependent RNA poly synthesizes - sense ssRNA for viral transcription and replication
Is SARS CoV2 genome in + or - sense
+ sense ssRNA
Did DNA or RNA come first???
RNA cause it can store genetic info and code for a.a. Like DNA and it can catalyze rxns like enzyme
Evidence that RNA came first
1.ribozyme (ribonucleic enzyme)->catalyze own synthesis and cleave RNA molecule
2. DNA made later and is more stable than RNA (ds)
