Term
| Griffin's experiment w/ pneumonia bacteria (in vivo) |
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Definition
(in body) injected mice with R-strain = mice lived
S-strain = mice died
heat-killed S-strain = lived
heat-killed S-strain & R-strain = died |
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Term
| Griffin's 4 conclusions and hypothesis |
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Definition
1.R-strain harmless 2.S-strain deadly 3.heat-killed S-strain harmless 4.heat-killed S-strain & R-strain deadly
hypothesis: heritable material being passed from S-strain to R-strain |
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Term
| 1950's experiment w/ viruses |
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Definition
*virus has protein coat on capsule & DNA, only DNA enters cell (in vitro)
*1st experiment: made DNA radioactive -> radioactivity in bacterium
*2nd experiment: made protein coat radioactive -> no radioactivity in bacterium |
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Term
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Definition
1.phosphate group
2.5-carbon sugar
3.nitrogenous group
1 & 2 make up sugar-phosphate backbone |
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Term
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Definition
pyrimidine- nucleic acid has single ring T&C
purine- nucleic acid has double ring A&G |
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Term
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Definition
*any life form has DNA: A T C G (unity)
*ratio of bases differ throughout speciies (diversity) |
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Term
| 3-D DNA structure discovery |
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Definition
*Rosalind Franklin took x-ray crystallography
*purine + purine= too wide
*pyrimidine + pyrimidine= too narrow
*Watson & Crick coined term double-helix & DNA has negative charge |
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Term
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Definition
*sugar-phosphate backbone runs in opposite directions
*5'-3'
*antiparallel |
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Term
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Definition
*DNA packaged efficiently by histones; positive charge binds w/ negatively charged DNA
*histone + DNA= nucleosome (basic unit of DNA packaging
*coiling of nucleosome-> 2nd level of DNA packaging |
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Term
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Definition
*semi-conservative: each existing strand serves as template for daughter strands
*sequence of bases on parent determine sequence of bases on daughter |
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Term
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Definition
1.Origin of Replication
2.DNA unwinds
3.DNA primed
4.DNA synthesis
5.Enzyme removes primer |
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Term
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Definition
1st step in replication
*proteins bind parent strands causing them to separate
*replication fork: within origin of rep, helicase found here |
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Term
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Definition
2nd step in replication
*helicase enzyme breaks down h-bonds that hold bases together
*causes "bubble" to grow wider
*proteins bind parent strands to keep them apart
*helicases break h-bonds b/t nucleotides |
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Term
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Definition
3rd step of replication
*primer laid down on parent DNA by primase enzyme
*primer is short strand of RNA |
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Term
DNA synthesis
(leading/lagging strand) |
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Definition
4th step of replication
*DNA polymerase III finds correct nucleotide to bring to growing daughter strand
*exergonic reaction: 2 P groups break off free nucleotide as it joins daughter strand
*leading strand: complements 3'-5' parent DNA proceeds in same direction of replication fork
*lagging strand: complements 5'-3' parent DNA formed in Okazaki fragments |
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Term
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Definition
5th step in replication
*DNA polymerase I removes primer
*ligase brings fragments of strands together, fuses "bubble" |
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Term
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Definition
*mutations caused by alcohol during pregnancy, radiation, PCBs or benzene
*DNA polymerase III checks back over nucleotides brought in
*excision repair: "cuts" out wrong base; a.helicase breaks h-bonds b.DNA polymerase III brings in correct base c.ligase joins bases |
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Term
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Definition
1.Base-pair substitution:one base is incorrect & isn't replaced, when DNA replicated right base pairs w/ 1st wrong base, causes mutation & frameshift
2.Insertion/Deletion: DNA poly. III doesn't catch mutation, extra base deleted or inserted |
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Term
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Definition
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Term
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Definition
1.mRNA: messenger, intermediate b/t DNA & protein
2.tRNA: transfer, delivers free nucleotide to mRNA
3.rRNA: ribosomal, brings a.a. to growing protein, 2 pieces make ribosome (large & small= interact ribo.) |
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Term
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Definition
*DNA -> RNA
*synthesized 5'->3'
*RNA polymerase catalyzes nucleotide addition |
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Term
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Definition
*Initiation: occurs at AUG on DNA
*Elongation: as RNA poly moves "down" DNA, DNA unwinds; "behind" RNA poly, H-bonds reform; mRNA peels off of DNA as it is transcribed
*Termination: terminator sequence, RNA poly leaves DNA here |
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Term
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Definition
*occurs in nucleus
1. 5' cap
2. 3' end -> poly-A tail: string of adenines added
3. exons/introns: introns cut out, exons remain in mRNA |
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Term
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Definition
*mRNA to protein
*nucleotides (A,U,G,C) -> a.a. (20 of them)
* Initiation, Elongation, Termination |
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Term
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Definition
*tRNA reads mRNA; anticodon reads codon
*diff order of codons make diff proteins
*Start (AUG) and Stop (UGA) codons |
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Term
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Definition
a. small ribosomal unit + tRNA + mRNA
b. large ribosomal unit sits on top; contains p site and a site for tRNA |
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Term
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Definition
a. codon recognition
b. peptide bond formation b/t a.a. on tRNA in P site and a.a. on tRNA in A site
c. translocation: tRNA in P site leaves, tRNA from A site moves to P site |
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Term
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Definition
| tRNA recognizes stop codon, binds A site, ribosome dissociates, protein synthesis finish |
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