BIO 116 Lecture Notes - Lecture 1: C4 Carbon Fixation, Vascular Bundle, Messenger Rna
BIO EXAM REVIEW
PHOTOSYNTHESIS
C3- typical plants , C4- bundle sheath cells(spatial separation of photosynthesis
because to avoid photorespiration( fixing O2 instead of carbon) RUBISCO fixes carbon.
C stands for carboxylase, O is for oxygenase. C4 plants live in hot dry climate. Corn,
pineapple. , CAM- temporal
DNA REPLICATION
Conservative: meselson and stahl: N isotopes --- 15N(heavy) and 14N(light). Took
bacteria growing in medium. Lots of nitrogen in dna, rna, and protein. Then moved cells
to another medium that had N14. it says DNA is replicated first with heavy dna, then
after one replicate, old heavy dna comes back and new light dna sticks together. Then
another replication-- 1 is all old, 2 is all new, 3 and 4 is all new/light
Semiconservative: half and half, one new one old for each copy, then after replication
1 is half and half 2 is all new, 3 is half and half 4 is all new
Dispersive: mismatch everything
TRANSCRIPTION
Enhancers: all cells have same genome, all cell tissue have different functions and
structures. Act like this is what genes get switched on and off. Switches are regulators:
promoters and enhancers, to get transcription to happen:factors (proteins) interact with
promoter.
Benefit of introns: increase proteome without increase genome. More mixtures of
polypeptides in genes, alternative splicing helps this. Spliceosome removes introns so
we end up with only exons.
Bacteria don’t have introns, some archaea have introns, but very true
In 116 if it has introns its eukaryote
Poly a tail and cap added after transcription by regulatory mechanism- enzyme that
adds A’s to end of message.
Operon- way bacterial genomes are organized. Prok. are smaller. Less genes.
TRANSLATION
Small subunit associates with messenger rna, then to tRNA to pair, then the large
subunit. Nucleic acid language to amino acid language. tRNA are the parts that are
talking to each other. Have to transfer amino acids. Then translocation. Whole moves
over. Can be reused. Translation stops with a stop codon. (UGA)
find more resources at oneclass.com
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Document Summary
C3- typical plants , c4- bundle sheath cells(spatial separation of photosynthesis because to avoid photorespiration( fixing o2 instead of carbon) rubisco fixes carbon. C stands for carboxylase, o is for oxygenase. Conservative: meselson and stahl: n isotopes --- 15n(heavy) and 14n(light). Lots of nitrogen in dna, rna, and protein. Then moved cells to another medium that had n14. it says dna is replicated first with heavy dna, then after one replicate, old heavy dna comes back and new light dna sticks together. Then another replication-- 1 is all old, 2 is all new, 3 and 4 is all new/light. Semiconservative: half and half, one new one old for each copy, then after replication. 1 is half and half 2 is all new, 3 is half and half 4 is all new. Enhancers: all cells have same genome, all cell tissue have different functions and structures. Act like this is what genes get switched on and off.