AQA Biology 8.1 structure of DNA


chapter 8.1
Charlotte Hewson
Flashcards by Charlotte Hewson, updated more than 1 year ago
Charlotte Hewson
Created by Charlotte Hewson over 8 years ago

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Question Answer
DNA is made up of three basic components. when these combine, what does this form? A nucleotide.
what three components is a nucleotide made up of? -A sugar called deoxyribose, -A phosphate group -An organic base
What two groups can the organic base belong to? a) Single ring bases - Cytosine and Thymine (C and T) b) Double ring bases - Adenine and Guanine (A and G)
How do the deoxyribose, phosphate and organic base combine? By a condensation reaction
What is the name given to: a) A single nucleotide? b) Two nucleotides? c)Three or more nucleotides? a) A mononucleotide b) A dinucleotide c) A polynucleotide
How do the mononucleotides join together between which components? by a condensation reaction between the deoxyribose of one mononucleotide and the phosphate group of the other mono, di or polynucleotide.
What is DNA made up of in terms of nucleotides? two long strands of nucleotides
how are the two strands of nucleotides joined together? By hydrogen bonds formed between certain bases
what is the difference between a C & G base pair and an A & T base pair? A & T pair by two hydrogen bonds where as C & G have three hydrogen bonds.
what is the word used to describe the pairings between the base pairs? complementary.
the number of A is the same as the number of T, and the same with C and G but what does differ between the pairs? the ratio, there could be more A & T than there are C & G pairs
what describes the overall structure of DNA? double helix
how many bases are there in one complete turn of the double helix structure? ten base pairs
what are four ways in how the DNA molecule is adapted to its function? -very stable and can pass through generations without change -two strands joined by hydrogen bonds so they can separate for DNA replication and protein synthesis -very large so can carry lots of genetic info -base pairs within the helical cylinder of the deoxyribose-phosphate backbone the genetic info if to an extent protected from corruption by outside chemical and physical forces.
what does A, T, C and G stand for? G = guanine (double ring) A = adenine (double ring) T = thymine (single ring) C = cytosine (single ring)
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