From Gene to Protein Flashcards
Who was the first person t connect human disorders and Mendels laws of inheritance?
Archibold Garrad
What did Archibold Garrad study?
Alkaptonuria
What were Archibold Garrads alkaponuria hypothesis?
Alkaptonuria patients lack the enzyme necessary for breaking down homogentisic acid
Lack of the enzyme is due to a defect in a gene
What mould Beadle and Tatum work on?
Neurospora
To test if genes were responsible for specific chemical reactions they irradiated Neurospora with what?
X rays
What is the one gene one enzyme hypothesis?
That each enzyme in a pathway was controlled by one gene
Role of a gene is to encode an enzyme - and that for each enzyme there is a gene
Describe the structure of RNA.
Ribose sugar
Uracil
Single stranded (usually)
What experiment provided evidence for mRNA?
Pulse chase- radioactive uracil
What are the two steps of protein synthesis?
Transcription
Translation
Summarise transcription
Transcription is the synthesis of a mRNA molecule using one strand of the DNA as a template such that G pairs with C and A pairs with U
What enzyme catalyses transcription?
RNA polymerase
Does RNA polymerase require a primer?
No
How many amino acids are there?
20
Who proved the amino acid code was 3 letters?
Crick and Brenner
What are groups of three bases called?
Codons
What was the first codon to be proved?
UUU (phenlalanine)
UAA UAG and UGA code for what?
Stop codon
What is the start codon?
AUG
What does redundant mean?
Amino acids can be specified by more than one codon
Why is the genetic code specific?
Each codon can only specify one amino acid
What direction does translation machinery run in?
5’ to 3’ along the mRNA
How is the correct reading frame obtained?
Starting with methionine (start codon AUG)
Summarise translation
The synthesis of protein using mRNA as template
