Chapter 8 - DNA, genes and protein synthesis Flashcards
What is a gene?
A gene is a sequence of DNA bases that code for either a polypeptide or RNA
How are genes involved in making proteins?
The order of DNA bases on a gene determines the order of amino acids in a particular polypeptide. This polypeptide then determines the primary structure of a protein
How many bases code for one amino acid?
Three
What is functional RNA?
RNA molecules, other than mRNA that perform special tasks during protein synthesis
*What is a cell’s genome?
The complete set of genes in a cell
*What is a cell’s proteome?
The full range of proteins a cell is able to produce
What are most amino acids coded by?
Between two and six triplets
What will all chains of amino acids start with?
Methionine - the start codon
What will all chains of amino acids include?
A stop codon
What does the term ‘non-overlapping’ mean?
Each base is read only once
What are introns?
Non-coding parts of DNA
What is a DNA molecule in a prokaryotic cell like?
The DNA molecules are carried as chromosomes, but are shorter and circular. The DNA supercoils to fit in the cell
What is eukaryotic DNA like?
It is a linear molecule that exists as chromosomes. The DNA molecule is so long that it must be would around proteins, called histones, to fit in the nucleus. This creates compact chromosomes
Which organelles in eukaryotic cells also have their own DNA?
Mitochondria and chloroplasts, but it is circular and shorter than other DNA in the nucleus
What are homologous pairs?
Pairs of matching chromosomes, which are the same size and have the same genes
*What are alleles?
Different forms of genes
What is the diploid number?
The total number of chromosomes in an organism
How do alleles differ?
They contain different base sequences so code for different proteins, which create different versions of the same polypeptide.
What are exons?
Sections of genes that code for amino acids
What are non-coding repeats?
Sections of DNA that are repeating (e.g. CTTCTTCTT) but don’t code for amino acids