10 - DNA and Protein synthesis Flashcards
Genetic code
The way in which DNA bases code for a sequence of amino acids is the genetic code. It is almost identical to all living organisms and this said to be universal.
Chromosome structure
Long DNA molecules supercoiled around histone proteins
How is DNA found in eukaryotic cells?
In chromosomes
How is DNA found in prokaryote cells?
Circular DNA
Plasmids
Gene
DNA with a base sequence that codes for the amino acid sequence of a polypeptide
Meaning of diploid?
Double the normal number of chromosomes
Meaning of locus?
The position of a gene on a chromosome
How many naturally occurring amino acids are there?
20
Meaning of Triplet?
The sequence of three bases on a DNA molecule that codes for an amino acid - necessary to be able to code for all 20 - gives 64 possible bases
Meaning of degenerate?
The same triplet can code for the same amino acid, so the code is said to be degenerate
‘Stop’ triplets?
3 degenerate triplets in a row
Non overlapping code?
The sequence of triplets is read sequentially and each three bases in a triplet will only be part of coding for 1 amino acid.
Sense strand?
The template strand on a helix of DNA that actually codes for a protein.
Meaning of genome?
The complete set of genes in a cell
‘Junk DNA’
The 98% of DNA that does not code for amino acids - do actually have functions - still researching