Phosphate , pentose sugar , organic nitrogenous base
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How does a nucleotide form
Two condensation reactions which releases two water molecules due to two bonds being formed
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What are the five bases
adenine thymine uracil cytosine and guanine
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How do nucleic acids form
a polynucleotide is created by condensation reaction of two or more nucleotides. A phosphodiester bond forms between the nucleotides and the sugar and phosphates bond together to create a sugar phosphate backbone
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Give the structure of DNA
A double stranded molecule with diuble helix shape.Made up of four bases which compliment each other and form hydrogen bons which joins the two strands together.the strands run anti parrallel
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What is a complementary base pairing rule
Adenine forms 2 hydrogen bonds with thymine and guanine in forms three hydrogen bonds with cytosine
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What are purines and what characterises them
Adenine and guanine and they have a double ring structure
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What are pyramidines and what characterises them
cytosine and thymine and have a single ring structure
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What is chargaffs rule
There must be equal amounts of adenine and thymine. And there must be equal amounts of cytosine and guanine.
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What is RNA
A single stranded polynucleotide
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Why do you mash the sample
to breakdown the cell wall
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Why do you add detergent to the sample
to breakdown the cell membrane
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Why do you add salt to the sample
to break the hydrogen bonds between the base pairs
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Why might you add protease enzymes to the sample
To breakdown the histone proteins in the nucleus
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When does DNA replication occur and by what process
it occurs during the interphase of cell division and it occurs by semi conservative replication
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What is semi conservative replication
It is were each new molecule has an old strand and a new strand of DNA
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How does the sequence of organic base is relate to its function
this sequence of bases determines the sequence of amino acids in the primary structure of a protein
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How does it been a long molecule affect its function
large amount of information can be stored
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How does complementary base pairing relate to its function
complementary strands of information can be replicated also allows for antiparallel strands
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how does the double stranded helix structure relate to its function
Give the molecule stability and bith strands acts as a template
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What is protein synthesis
making proteins
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What is transcription and were does it happen
It happens in the nucleus DNA is copied to mRNA which is translated at the ribosome DNA is too large to leave the pause in the nuclear envelope
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What happens just after transcription before translation
the MRNA then detaches from the dnn templates of leaves the nucleus via a nuclear pore the DNA double helix reformes then the Mrna molecule travel to ribosomee for the next stage
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What is a genome
The entire DNA seauence of the particular organism
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What is a gene
Length of DNA that codes for one or more polypeptides
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