Previously on Bio308

1
Previously on Bio308
Genes definition and parts
Nucleic Acids
DNA basic parts, the bonds that link bases
into strands the bonds that make strands into
double helix
RNA basic parts and bonds differences between
it and DNA types of RNA in the cell
Transcription Copying genetic information from
DNA to mRNA what are the steps? (transcription
and processing) where does it occur? why is it
necessary?
2
Now on Bio308
Translation Converting the blueprint into a
working model
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Nucleotides to proteins Step II
Questions
Are cytosolic and integral membrane proteins
transcribed the same way? Are they translated
the same way?
4
Three basic steps
Initiation
Elongation
Termination
From nucleotides to amino acids---How?
5
Two adaptors used tRNA and amino acyl
tRNA-synthetases
Codons, Anticodons, and Wobble
Charging of tRNA
Basepairing with a tRNA
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That Degenerate Genetic code
codons gt tRNAs gt aminoacids
CCAGAGCAGACUGCUUAGCUUCAUCCCACGAACGGGAG
How did they figure out the genetic code?
Strings of identical nucleotides Nirenberg
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Initiation
Players?
How does the complex know where to start
translating?
In Bacteria?
In eukaryotes?
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Elongation
CBI 6.4 Translation
Players?
Requires GTP hydrolysis
Results in peptide bond formation
Chain grows from N to C
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Termination
Players?
mRNA
Termination factors
Ribosome
How does it work? Why does the chain end?
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The Protein
What happens to the protein?
Folding
Sorting
What happens to the mRNA, the ribosomes the
tRNA?
Reuse
Polysomes
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Translation, Bipolar Disorder, and
What does this have to do with bipolar disorder?
Nobel Prize for Medicine 2000 Dopamine as a
neurotransmitter and its role in brain
dysfunctions
(Dopamine is the catecholamine implicated in
bipolar disorder)
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Tale of 2 proteins--a stretched metaphor
Protein 1 Many neurotransmitters are amino
acids, amino acid derivatives (like dopamine),
or short peptides
Synthesized in cytosol sorted/packaged into
vesicles for use
Protein 2 Neurotransmitter receptors are
proteins. Synthesized in cytosol, inserted into
ER membrane and sent to proper location on
plasma membrane
Broad Hypothesis Perhaps Bipolar is a result of
problem(s) Getting the transmitters or the
receptors to the right place at the right time.
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Broad Idea Perhaps Bipolar is a result of
problem(s) getting the transmitters or the
receptors to the right place at the right
time?
How do we study this?--- examine what should
happen and look for changes from that standard
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Synaptic vesicles
What are they?