4.1.4 Genes Flashcards
A gene is
a base sequence of DNA
A gene is a base sequence of DNA that codes for
amino acid sequence of a polypeptide or a functional RNA molecule
Functional RNA molecules are required for
protein synthesis
mRNA
the base sequences on messenger RNA molecules are used by ribosomes to form polypeptide chains
tRNA
carry amino acids to the ribosome
rRNA
form part of the structure of ribosomes
The shape and behaviour of a protein molecule depends on
the exact sequence of these amino acids
The initial sequence of amino acids is known as
the primary structure of the protein molecule
The genes in DNA molecules, therefore, control
protein structure (and as a result, protein function)
The genes in DNA molecules, therefore, control protein structure (and as a result, protein function) as they determine
the exact sequence in which the amino acids join together when proteins are synthesised in a cell
A gene is a sequence of nucleotides that codes for the production of a specific protein molecule (polypeptide)
One gene codes for one
mRNA molecule
One gene codes for one mRNA molecule, which codes for one
polypeptide
One gene codes for one mRNA molecule, which codes for one polypeptide., this is known as
the central dogma of molecular biology
each chromosome in a human cell nucleus contains one
very long DNA molecule
Each chromosome in a human cell nucleus contains one very long DNA molecule, this DNA molecule is made up of thousands of
specific nucleotide sequences
This DNA molecule is made up of thousands of specific nucleotide sequences called
genes
This DNA molecule is made up of thousands of specific nucleotide sequences called genes that code for
specific proteins
Even though these genes are all found within the same DNA molecule and are therefore all linked up, the cell knows where individual genes
start and stop
This ensures the cell reads the DNA correctly and can produce the correct
protein molecules that it requires to function properly
