Genetic Lecture 5 Flashcards
The order of the gene idea?
Chaldean Pedigree (4000 BC), Mendel’s heritable factor (1857), Darwin’s variation in traits (1859), Chromosome theory (early 20th century), Watson & Crick (1953), Genetic code deciphered (1960’s).
Chaldean Pedigree
A very very old believe pedigree of horses, where you can see the select of certain genes by crossing horses. Since the beginning of agriculture people have been trying to select different traits in livestock/plants.
Mendel’s part in the gene idea?
He figured out you have genes.
Darwin’s part in the gene idea?
That we need variation and natural selection in these genes for a population to survive.
Chromosomal Theory
Saw that you had chromosomes and thought genes might be on these.
Watson & Crick’s part in the gene idea?
It’s actually DNA that carries the genes and information.
How old is the gene idea?
The ideas of genes (that we have these packets of info that get passed along from one generation to the next) is really old.
What does one gene code for?
One polypeptide (protein)
Difference between a polypeptide and protein?
Polypeptides don’t have a function, while protein has a function and is made up of several polypeptides.
What do enzymes do?
Catylize chemical reactions.
For the game to work what must happen?
All the enzymes must be functional.
Prospero
A haploid organism (protein).
How many genes can you have on a chromosome?
Multiple
How are traits made possible?
By the presence of several different proteins.
Acetylcholine to arginine
4 steps where the precursor (acetylcholine gets transferred into arginine (important component for the organism to live).
The idea of one gene makes one polypeptide led to what?
Francis Crick’s (1957) idea of the central dogma of molecular biology. Transcription and translation (DNA to mRNA to ribosome to polypeptide).
Dogma
A set of rules that cannot change.
The 2 important principles of the central dogma of molecular biology?
Genetic information moves from DNA to RNA to protein. No information can get back the other way: protein to DNA.
Where is the gene coded on?
The template strand of DNA.
What must happen to be able to code the proper protein?
You need to have all codons perfectly back to back along the stretch of mRNA.
Codon
Sequence of three nucleotides that forms a unit to code for an amino acid.
What do eurkayotes have a lot of?
Junk DNA (what lies between the genes). They are back to back and are regulated together.
Transcription
The process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA). This occurs in the nucleus.
Transcription example?
Think: photocopy of a recipe in a recipe book (the DNA ‘book’ can’t leave the library). Still instructions on a page using the same ‘alphabet’)
DNA»_space;»»»»»»»»»RNA
4 letter alphabet. 4 letter alphabet
(A,T,G,C) (A,U,G,C)
Translation
The process by which a cell makes proteins using the genetic information carried in messenger RNA (mRNA). This occurs in the cytoplasm.
Translation example?
Think: making the dish from the photocopied recipe.
Uses many ingredients
RNA»»»»»»»»PROTEIN
3 letter ‘words’ 20 ingredients
(codons) (amino acids)