Feb3, Feb 5, FEb 7th Flashcards
(24 cards)
How do we get from a genotype to a phenotype
DNA-transcription-RNA-translation- protein -> phenotype
Or(reverse transcription)
DNA- transcription - RNA - Reverse transcription - DNA
1.Information is stored in DNA 2. Transcription - The info in dNA is copied into RNA 3. Translation 4. The info in RNA guides the production of proteins 5. Phenotype
Central dogma of molec biology -
Information flow from ________________________ in order to convert _______ to ________
The information flow is _________. It’s _______ to all forms of life
DNA to RNA to protein , genotype to phenotype, universal , common
Some viruses can perform _______ ______
Name the central dogma
Reverse transcription,
DNA POLYMERASE ( replication DNA->DNA)->DNA -> (transcription (DNA->RNA) ) RNA POLYMERASE -> RNA -> translation (RNA-> Proteins) RIBOSOME -> PROTEIN
_____________ = Transcription and translation both occur in the cytoplasm. Therefore,
both processes can occur simultaneously.
• ________________________: Transcription and processing of the precursor ____ molecules occur in
the nucleus and translation occurs in the cytoplasm.
Prokaryotes, eukaryotes, mRNA
(There’s a pic here learnnnnnn) slide 5 feb 3
1940s: ________________________ hypothesized that genes encode enzymes that
function at each step of a biosynthesis pathway needed to make an essential nutrient
• Investigated a biosynthesis pathway in the mould Neurospora
Mutating a gene encoding an enzyme would cause a _____ in the metabolic pathway and the
organism can no longer synthesize the needed nutrient
• _________________: organism that cannot make its own essential nutrients (ie ‘nutritional mutant’)
Q: what happens if only gene x is mutated ?
Q: What nutrients could be added in order for mutant X to live?
Beagle and Tatum, block , auxotroph
Gene X -> Gene Y -> Gene Z->
(Arrow down each)
(Precursor)A->Enzyme X -> B->Enzyme Y -> C-> Enzyme Z-> Amino acid D (essential nutrient)
Q1: a lot of A
Q2: B, C, D
Arginine auxotrophic mutants
Wild type can grow on __:_____ _____ - salts , ______, ________
UV on Neurospora
crassa-> Isolate mutants that ____ to
grow in the ________ of
arginine->Each mutant has a
defective gene for an
enzyme needed to
_______ an ________
________ to produce ________.
MM, minimal media , sugar , vitamins
Synthesize
Uv on Neurospora
crassa-
Isolate mutants that fail to
grow in the absence of
arginine
Each mutant has a
defective gene for an
enzyme needed to
synthesize an intermediate
product to produce arginine
Enzyme 1 Enzyme 2 Enzyme 3 MM (precursor) ->Ornithine -> Citrulline -> Arginine (amino acid )
Central dogma of molecular biology
DNA(DNA replication) -> transcription (synthesis of RNA from DNA template) -> RNA -> Translation (synthesis of protein using RNA instructions) -> protein
Arginine auxotrophic mutants
_____ ____ can grow on MM : minimal media - ____, ____ , _____
Wild type , salt, sugar, vitamins
Strain:
_____ ____ (_____) -> Grows on MM, and on all other ___________ media.
Arg-4 mutant -> Does ____ ____ on MM: grows on all other supplemented media, (________,________,_________)
_____ _______ -> does not grow on MM; grows if______ or ________ is in the medium, but not if only ornithine is in the medium
________ __________ -> Does not grow on MM; grows if -________ is in the medium, but not if only _______ or_________ is in the medium.
Gene one polypeptide -
Wild type (control) -> Grows on MM, and on all other supplemented media.
Arg-4 mutant -> Does not grow on MM: grows on all other supplemented media. (omithine, citrulline, arginine ).
Arg-2 mutant -> does not grow on MM; grows i citrulline or arginine is in the medium, but not if only or think is in the medium
Arg-1 mutant -> Does not grow on MM; grows if arginine is in the medium, but not if only ornithine or citrulline is in the medium.
Precursor -> Arg 4-> ornithine -> Arg 2 -> citrulline -> Arg 1 -> Arginine
Information flow occurs in certain places on chromosomes called ________
Genes
Genes encode for two types of RNA:
1.
_______________(mRNA): codes for a
protein/polypeptide
2. __________________ (tRNA, rRNA, snRNA,
microRNA): does not code for a protein
Coding RNA, Non-coding RNA
THERES A LONG PIC HERE LEARNNNN SLIDE 4 FEB 5
•Information contained in _ _______ bases in DNA (A,T,G,C) or RNA (_, _, _, _) sequences
•How many nucleotides required to code for __ diffERENT ______ acids in ___________?
If the code used…
• One-letter ‘words’:
• Two-letter ‘words’:
• Three-letter ‘words’:
____________________
____________________
____________________
•DNA :Three-letter code:
____________
•RNA: Three-letter code:
____________
•Genetic code is ________*
(____ code in prokaryotes, eukaryotes & viruses)
*some rare exceptions
4 nucleotide bases, RNA (A, U, G, C), 20 different amino acids in polypeptides, 4 amino acids, 16-amino acids, 64 amino acids! , DNA - triplets, RNA - codons , universal , same code
*SOME RARE EXCEPTIONS
Universal genetic code can allow foreign genes to be
________ and ________ in different ____ organisms
•Green fluorescent protein (GFP/RFP/YFP) isolated from jellyfish _______ ______
•Main application is to monitor the _____ and _______
expression of a _______
Universal genetic code can allow foreign genes to be
transferred and expressed in different host organisms
•Green fluorescent protein (GFP/RFP/YFP) isolated from
jellyfish Aequorea victoria
•Main application is to monitor the spatial and temporal
expression of a protein
Template and Coding DNA strands
• In general, for every gene, an RNA molecule is only produced from ___ of the
___ strands (ie: the gene is ______ on one of the strands)
• One strand is the ________________ strand (also called the antisense strand or noncoding strand)
• This strand is read from ________’ by the RNA polymerase
• The other strand is the __________________ strand (also called _________ strand, or ______ strand)
• This strand looks the same* as the mRNA molecule (except with ______ instead of thymine)
5’ = __________________
3’ = __________________
mRNA transcript is synthesized in the_____________
direction (by the RNA polymerase)
7Chang-Hui Shen, 2023. Diagnostic M
Template and Coding DNA strands
• In general, for every gene, an RNA molecule is only produced from one of the
DNA strands (ie: the gene is encoded on one of the strands)
• One strand is the template strand (also called the antisense strand or noncoding strand)
• This strand is read from 3’ to 5’ by the RNA polymerase
• The other strand is the non-template strand (also called sense strand, or coding strand)
• This strand looks the same* as the mRNA molecule (except with uracil instead of thymine)
(
5’ = sense __________________
3’ = template __________________
mRNA transcript is synthesized in the 5’ to 3’
direction (by the RNA polymerase)
7Chang-Hui Shen, 2023. Diagnostic M
5’-ATGTTCCGCGATAAGCTTTAA-3’ -
3’-TACAAGGCGCTATTCGAAATT-5’ -
5’-AUGUUCCGCGAUAAGCUUUAA-3’ -> _________mRNA (codons)
N-MET-PHE-ARG-ASP-LYS-LEU-(STOP)-C -> _______ ___________ (amino acids)
• Transcription (mRNA synthesis) occurs in the ____________ direction
• In translation (protein synthesis), the mRNA codons are read in the ___________ direction
5’-ATGTTCCGCGATAAGCTTTAA-3’- sense
3’-TACAAGGCGCTATTCGAAATT-5’- template
5’-AUGUUCCGCGAUAAGCUUUAA-3’ -> Transcription - mRNA (codons)
N-MET-PHE-ARG-ASP-LYS-LEU-(STOP)-C -> _translation -> Polypeptide (amino acids)
• Transcription (mRNA synthesis) occurs in the 5’ to 3’ direction
• In translation (protein synthesis), the mRNA codons are read in the 5 to 3’ direction
Template and coding DNA strands on chromosomes
• On chromosomal maps, genes are shown on as arrows on the
_______________ ______
Coding strand for Gene X
Gene X
5’ ———-> 3’ - (CANT EXPLAIN CHECK 9SLIDE FEB5)
3’ ————> 5’
Template strand for Gene X
Question: Draw the direction of synthesis for the Gene X mRNA.
Genes (coding strand on top DNA strand)
~4,000 genes
Genes (coding strand on bottom DNA strand)
Template and coding DNA strands on chromosomes
• On chromosomal maps, genes are shown on as arrows on the
__sense strand
Coding strand for Gene X
Gene X
5’ 3’
3’ 5’
Template strand for Gene X
Question: Draw the direction of synthesis for the Gene X mRNA.
Genes (coding strand on top DNA strand)
~4,000 genes
Genes (coding strand on bottom DNA strand)
5’ to 3’
Central dogma of molecular biology
DNA -> Transcription -> RNA -> Translation -> Protein -> phenotype
OR = DNA -> Transcription -> RNA -> Reverse transcription -> DNA REPLICATION
Reverse transcription ->
•Reverse transcriptase is in some viruses with ______________________ (e.g.
retrovirus).
•Viral RNA needs to be converted into ______ ____ in order to _____ into the
host’s chromosome.
•The host’s _______ and ________ machinery is hijacked to produce viral
________ from the viral DNA.
How can we use this knowledge to design anti-viral drugs?
•Reverse transcriptase is in some viruses with __RNA GENOMES (e.g.
retrovirus).
•Viral RNA needs to be converted into viral DNA in order to integrate into the
host’s chromosome.
•The host’s transcription and translation machinery is hijacked to produce viral
proteins from the viral DNA.
How can we use this knowledge to design anti-viral drugs?
AZT inhibits RT
___________ ___ because besides able to store genetic information
(code for amino acids like DNA), can also ________ reactions (like an enzyme)
•
____________________ (ribonucleic acid enzymes) can catalyze their own synthesis and ______ ___ molecules (2° structure)
•DNA developed later with advantages over ___ such as ___________________, and _____ _______ allows the complementary strand to be used as a template to repair the damaged strand
LIKELY RNA because besides able to store genetic information
(code for amino acids like DNA), can also catalyze reactions (like an enzyme)
•
RIBOZYMES (ribonucleic acid enzymes) can catalyze their own synthesis and
cleave RNA molecules (2° structure)
•DNA developed later with advantages over RNA such as ___MORE STABLE, and double
stranded allows the complementary strand to be used as a template to repair the damaged strand
•An organism’s phenotype is dependent on
__________________________________.
•Every cell in an organism has ____________________
(DNA sequence).
•An adult human has approx. 1014 cells composed of
_______ different cell types.
•Different genes are being turned on (_____ ___)and off in different
cell types and at different times in development. This
differential expression arises from
____________________________.
•An organism’s phenotype is dependent on
Cell number , type , function.
•Every cell in an organism has _identical genome (DNA sequence).
•An adult human has approx. 10^14 cells composed of
_200+ different cell types.
•Different genes are being turned on (make mRNA) and off in different
cell types and at different times in development. This
differential expression arises from
__transcriptional regulation .
Regenerative medicine: Growing a desired tissue type by ________ __/__ the appropriate genes using _________ techniques.
Regenerative medicine: Growing a desired tissue type by turning
on/off the appropriate genes using molecular techniques.
________ includes promoter and transcriptional unit.
•(Transcriptional unit: part of the gene that is copied into RNA)
•
________________ DNA sequence (including TATA box) that specifies where __________ begins on the
chromosome.
•The promoter is located immediately ________________
of transcriptional start point
•The promoter sequence is defined as the sequence found on the ___________________ (non-template)
•The promoter is recognized and bound by the transcriptional machinery
(________________________________________________) that initiate transcription.
_Gene includes promoter and transcriptional unit.
•(Transcriptional unit: part of the gene that is copied into RNA)
•Promoter DNA sequence (including TATA box) that specifies where transcription begins on the
chromosome.
•The promoter is located immediately _upstream(5’)
of transcriptional start point
•The promoter sequence is defined as the sequence found on the _sense DNA (non-template)
•The promoter is recognized and bound by the transcriptional machinery
(_____RNA polymerase and transcription facts ) that initiate transcription.
On chromosomal maps, genes are shown on as arrows on the_______ ___
On chromosomal maps, genes are shown on as arrows on the coding strand
THERES PICS SLIDE 10 FEB 7
