Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
48 Cards in this Set
- Front
- Back
|
Four bases of DNA |
Adenine Guanine Cytosine Thymine |
|
|
Experiments on virulence in mice done by... on... |
Griffith, streptococcus pneumoniae |
|
|
Explain Griffiths experiment |
S and R strains and virulence. Concluded that some substance from the capsule and virulence must have passed from s to r strain, causing it to transform. Phenotype changed genotype. |
|
|
Three requirements of genetic material |
1. Store information on development, structure, metabolism. 2. Stable enough to be transferred to the next generation. 3. Undergo rare changes/mutations for genetic variation. |
|
|
Avery's experiments |
Similar to Griffith with Protease to kill protein and DNAase to kill DNA. Protease had no effects on R strain, meaning DNA was the transforming substance. |
|
|
Tagging material from jellyfish |
Green Flourescent Protein GFP. |
|
|
Purine |
A, G |
|
|
Pyrimidine |
T, C |
|
|
Hershey & Chase experiments |
Tagged protein coats or DNA of bacteriophage that infects bacteria. Determined that virus releases DNA to take over, meaning it contained genetic information. |
|
|
Chargraff's Rule |
1. Amount of A, T, C,G is constant in the same species. 2. Each species has the same amount of A=T and C=G |
|
|
Rosalind Franklin |
X ray diffration studies DNA structure. Viscous solution of DNA is centrifuged, it can be separated into fibres. They can produce a pattern. Evidenced: DNA helix, and some portion of helix is repeated. |
|
|
Watson and Crick Model |
Deduced DNA is double helix with sugar phosphate backbone and paired bases on the inside. Hydrogen bonded bases as rungs. They it mathematical measurements of X ray diffraction. Agreed with Chargraff's complementary base pairing. Pyramidine bonds to purine. |
|
|
End of 3' end |
OH |
|
|
End of 5' end |
P |
|
|
Replication occurs from whch side? |
5' to 3' |
|
|
DNA replication |
Process of copying a DNA molecule |
|
|
Semiconservative Replication |
Each strand of the original DNA parental molecule serves as a template or model for a new strand in a daughter molecule. |
|
|
DNA replication steps |
1. Unwinding 2. Complementary base pairing 3. Joining |
|
|
Melso and Stahl demonstrate semiconservative replication |
They placed DNA in heavy nitrogen medium so all would contain it. Then into a light nitrogen. When tested after first replication, DNA were medium weight. After the second, half were light, the other were medium. |
|
|
Prokaryotic Replication |
Single circular loop of DNA. Moves 5' - 3'. Two identical circles. Takes 40 minutes, but done every 20. |
|
|
Eukaryotic Replication terminology |
Replication fork where two strands split. Replication bubble, where there are two strands forming. |
|
|
Beadle and Tatum |
On fungus to propose one-gene-one-enzyme theory. |
|
|
Process of Replication (on the DNA) |
Helicase unwinds DNA. DNA polymerase gathers nucleotides and joins them. Lagging strand is 3' to 5' so: RNA primer lays down a short RNA. Binding proteins stabilise new strand. Creates Okazaki fragments. DNA polymerase removes RNA primer U with T. DNA ligase joins the fragments. |
|
|
RNA vs DNA |
Single strand Sugar ribose instead of deoxyribose. Uracil instead of Thymine. |
|
|
mRNA function |
Takes a message from DNA in the nucleus to ribosome in the cytoplasm. |
|
|
rRNA |
Makes up ribosomes, reads the message in RNA. |
|
|
tRNA |
Transfers appropriate amino acids to the ribosomes for protein synthesis. |
|
|
Why replication has few mutations. |
1 mistake per 100 000. DNA polymerase will id and fix, making mistakes every 1 in 1 billion (proofreading). DNA repair enzymes try to fix damage, especially by environmental issues. |
|
|
Properties of the genetic code |
Universal, Degenerate, Unambiguous, contain stop and start signals. |
|
|
When gene transcripts, result is? |
pre-mRNA. |
|
|
Modifications to mRNA |
Cap on 5' end (modified G molecule), Poly-A tail on 3', introns spliced. |
|
|
RNA splicing |
Introns spliced by splicosomes, remaining exons spliced back together. |
|
|
Prokaryotic Splicing |
Introns are self-spliced enzymatically. |
|
|
Functions of Introns |
As organismal complexity increases, introns increase. Might combine in many combinations. Introns regulate gene expression. May encourage cross-over. |
|
|
tRNA has two binding sites |
One associates with mRNA, the other with a specific amino acid. |
|
|
Differences in tRNA |
One end bears a specific triplet called anticodon. Other end binds with amino acid. tRNA synthases attach amino acid to tRNA. |
|
|
rRNA |
Produced from DNA template in the nucleolus.Combined into large and small subunits. |
|
|
Three binding sites |
E for exit P for peptide A for amino acid |
|
|
Components necessary for initiation |
Small ribosomal subunit Large ribosomal subunit Initiator tRNA mRNA transcript Initiation factors (protein to bring these together) |
|
|
Initiator tRNA |
Always had UAC, carries methionine, bind to P site. |
|
|
Elongation |
Growth of the polypeptide |
|
|
Termination |
Previous tRNA moves to P site. STOP codon is UAA, UAG, UGA. No amino acids. |
|
|
Release factor |
Binds to the stop codon and cleaves polypeptide from the last tRNA. |
|
|
What made Gerrod think there were inborn errors in metabolism? |
Family members often had the same disorder, said it could be caused by the lack of an enzyme in the metabolic pathway. Hypothesised link between genes and proteins. |
|
|
Haemoglobin deficiency |
Difference in charge between sickle and normal cells. Thus leads to change in protein structure. Normal has negative charged glutamate, sickle cell has neural valine. Less soluble so it precipitates. |
|
|
Explain triplets being Degenerate |
Most have more than one codon, protecting against mutations |
|
|
Explain triplets being unambiguous |
Each triplet has only one codon |
|
|
Describing translation |
1. Initiation, elongation, termination. |
