B6 Genetics Flashcards
Genome
The entire genetic material of that organism
Chromosomes
The DNA is found within structures
Gene
A short section of DNA that contains the instruction for one characteristics of an organism
DNA genes and chromosomes
Human cells have 46 chromosomes
DNA has proteins associated with it that help condense into chromosomes
Mitochondria contain DNA
Plasmids contain DNA but don’t contribute to the running of the cell
Gene therapy and genome edititing
Developing effective treatments to target and correct genes
Understanding someone’s genome may allow doctors to:
Recommend better preventative medicine
Identify the targets of drugs more effectively
Tailor healthcare to the individual
Understanding more about the human genome
In late 20th C it was estimated that there were around 1000000 genes in the human genome
There are much less however 20000-25000 code for proteins this around 1.5% of the human genome
There are no coding areas which control gene expression turning on and off genes
The Genographic project
Looks at characterises on the male Y chromosomes and DNA in mitochondria from women
What were the findings of the TGP
That people originated from Africa
And that they migrated 60000 years ago through Arabia
Structure of DNA
A double helix structure
Like a gently twisted ladder
Bases in DNA
Adenine A
Thymine T
Cytosine C
Guanine G
DNA is a polymer
Made up of repeating units call nucleotides
Genetic code
Is the bases that make up this
Our genome contains approximately 3.3billion base pairs
Genes vary in size from a few hundred bases for more than 2 million
Complementary base pairs
A&T
C&G
Genes are needed to assemble proteins
Genes provide code for assembly of proteins
All proteins made up of same 20 amino acids
4 base pairs work in triplets for each amino acid
Protein synthesis
DNA unzips the bases of a gene act as template for a messenger molecule
Messenger molecule leaves the nucleus containing the code for the amino acid
In the cytoplasm the messenger molecules attaches to a ribosome
The base pairs are complementary. The carrier attaches to the ribosome
A second amino acid is ferried to the ribosome
The second amino acid is able to attach because of the sequence of its bases
A peptide bond is formed between the two anime acids
The messenger molecule is shunted along the ribosome and another amino acid is ferried in
The shape of proteins
Proteins bend into unique shapes creating an active site
When a complementary substrate fits into its active site a reaction can occur