Structure of DNA Flashcards
what is the genome
the entire genetic material of an organism
where is DNA contained
in the nucleus of a cell in structures called chromosomes
what is a gene
a small section of a chromosome
what is the purpose of genes
they code for proteins which is how they are expressed
what is the structure of dna
it’s a polymer made of repeating units called nucleotides
what do nucleotides consist of
sugar, phosphate, base (A,T,C,G)
how are the strands of dna structures
each molecule of dna has two alternating strands (sugar and phosphate) which are twisted together to form a double helix.
what joins the double helix strands in dna together
between the strands are the bases (A&T, C&G), which are joined to their pairs by hydrogen bonds
what is the process of making proteins called
protein synthesis
what does the order of bases on dna dictate?
the order of bases dictates what the genes code for, to make certain proteins.
a sequence of 3 bases codes for 1 amino acid
how are proteins synthesised
1) the double helix straightens out
2) as it straightens the hydrogen bonds break and the dna separates from the base pairs
3) floating nucleotides come into nucleus from cytoplasm (A,T,C,G)
4) new bases that come in are complementary to originals and they pair together creating 2 sets of dna
what is a mutation
a change in the structure of dna
