DNA & Genetic Code (Miss Reynolds) Flashcards
Chromosome
A thread like structure made of protein and DNA by which heriditary information is physically passed from one generation to the next.
Gene
Section of DNA on a chromosome that controls a feature by coding for information of one or more specific polypeptides.
Allele
Alternative forms of a particular gene with different base sequences and therefore different codes.
Genetic Code
Sequence of bases in DNA codes for the sequence of amino acids in a protein.
What are the 3 key features of the genetic code?
It’s a degenerate, non-overlapping and universal code.
Degenerate Code Meaning
Most amino acids are coded for by more than one triplet.
Non-overlapping Code Meaning
Each base appears in only one triplet.
Universal Code Meaning
It is the same in all known living things.
What type of code is the genetic code?
A triplet code, 3 bases = 1 amino acid.
DNA in prokaryotic cells and eukaryotic cells?
Pro - Ciruclar strands (no chromosomes)
Euk - Nucleolus is present, chromosomes present, in which DNA is located. Also in chloroplasts/mitochondria.
Nuclear enevelope in prokaryotic cells and eukaryotic cells?
Pro - No
Euk - Has a distinct nucleus, nuclear envelope.
Cell wall in prokaryotic cells and eukaryotic cells?
Pro - Peptidoglycan
Euk - When present, cell wall made mostly of cellulose.
Flageullum in prokaryotic cells and eukaryotic cells?
Pro - Sometimes present.
Euk - Sometimes present.
Ribosomes in prokaryotic cells and eukaryotic cells?
Pro - 70 sub units (smaller)
Euk - 80 sub units (larger)
Plasmid in prokaryotic cells and eukaryotic cells?
Pro - Sometimes present.
Euk - Not present.
