One Gene - One Polypeptide Flashcards
U1L3
What is a gene?
A gene is a specific sequence of DNA that defines one particular trait of an organism’s characteristics.
What’s a genome?
It’s the sum of all DNA carried in an organism’s nucleus.
Each chromosome has a set of genes.
Each species has its own unique arrangement, number
and type of genes
What do genes do?
Genes code for proteins.
Proteins are responsible for 98% of the processes found in the human body.
Who discovered the relationship between genes and enzymes?
Beadle and Tatum
How did Beadle and Tatum discover the relationship?
They exposed bread mole to radiation and put the mutates molds into different growth mediums (only amino acids were present in those mediums).
They discovered that the bread mold did not grow in all of the mediums, rather, they figured out that the molds only grew in the mediums that contained the amino acids required by the bread mold.
What’s the gene that was mutated in Tatum’s mold experiment?
ArgH. It prevented Arginine synthesis which as an Amino Acid.
What did they determine from this experiment?
They determined that Mutated molds had specific nutritional requirements (like humans).
The molds could not survive without having certain vitamins/amino acids added to their diet.
Mutated molds required an external supply of the substances that certain enzymes normally produced.
Why is their experiment relevant?
The experiment demonstrated that genes code for polypeptides (proteins).
Some proteins are made up of several polypeptide chains.
Mutations in the genetic sequence can affect the functionality of the protein.
