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What did Griffith do?
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Transformation factor
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terms list
What did Griffith do?
Transformation factor
What did Avery do?
Transformation factor was DNA
What did Chargaff do?
Found that % of C=G and % of T=A
What did Hershey-Chase do?
Proved that DNA was genetic material
What did Franklins do?
Found that DNA must be a helix
What did Watson-Crick do?
Stole others work to make first accurate DNA model
What is the Chargaff rule?
% of C=G and % of T=A
When does DNA replication occur?
S phase
What does Polymerase do?
Lays down nucleotides on the split DNA and removes RNA primer, also proofreads finished copy
What does Primase do?
Links RNA nucleotides into a primer
What does Helicase do?
untwists and separates DNA strands
What does Ligase do?
joins Okazaki fragments by making covalent bonds
What does SS binding do?
Keeps the DNA from binding during replication
Limitations of DNA polymerase:
Can only add to free 3' end, Can't initiate synthesis without RNA primer ( needs RNA primase )
5' to 3' significance:
-
Antiparallel definition:
The sugar-phosplate backbones of DNA run in opposite directions.
Leading vs lagging strands / fork meaning:
leading strand- smooth side, replication goes with splitting direction.
lagging strand- rough side, replication goes against splitting direction
Okazaki fragments:
Small fragments of DNA produced on the lagging strand
What is chromatin / histones:
DNA coils around histones to form nucleosomes which keep coiling to create chromatin fibers.
Chromatin fibers supercoil to make chromosomes
Central Dogma of Biology
DNA-transcription-RNA-translation-protein
DNA nucleotide bases vs RNA nucleotide bases?
There is no thymine (T) in RNA.
What does RNA polymerase do?
binds to DNA during transcription and separates the DNA strands
Where does transcription happen?
inside the nucleus
How does transcription work?
Information in DNA is transcribed on Messenger RNA
What type of RNA is involved in transcription?
mRNA
What organelle is involved in transcription?
nucleus
Intron vs Exon
Introns are non coding segments of RNA, Exons express themselves.
Where does translation occur?
ribosomes in the cytoplasm
How does translation work?
- mRNA leaves the nucleus and finds a ribosome
- tRNA, carrying an amino acid, matches its anticodon to the codon on the mRNA
- this continues and an amino acid chain is made
- when the mRNA reaches a stop codon, the matching tRNA releases the protein and synthesis is complete
What type of RNA is used during translation?
tRNA
What organelle is involved in translation?
ribosome
Why is DNA read in triplets?
That is the smallest combination of base's that allow for 20 amino acids.
What organisms use the genetic code table we studied?
All of them. This is why amino acids support evolution theory.
What is a nonsense mutation?
change resulting in early stop codon
What is a missense mutation?
one amino acid substituted for another
What is a silent mutation?
alters a base but does not change the amino acid
What is a frameshift mutation?
insertions or deletions of DNA, causes reading frame to be moved.
What is inversion mutation?
reverses a segment within a chromosome
What is a translocation mutation?
Pieces of non-homologous chromosomes break off and are reattached to the wrong chromosomes
What is a deletion mutation?
one nucleotide is taken away from a gene or DNA sequence
What is a duplication mutation?
a segment of a chromosome is repeated
What are Amino Acid tables based on?
mRNA
