DNA (replication) and RNA
Describe the structure of a nucleotide
- Phosphate group
- Organic bases
- Pentose sugar
What are the four base pairs in DNA?
Cytosine, guanine, uracil, adenine and thymine
By what bonds are the structures of DNA joined?
Phosphodiester bonds
Describe the structure of RNA
- Short polynucleotide chain
- Pentose sugar is ribose
- Organic bases: all except thymine (DNA only)
Describe the structure of DNA
- Organic bases: Thymine, guanine, cytosine, adenine
- Deoxyribose
-Phosphate group
Describe the 5 steps of DNA replication (DNA helicase..., Double helix..., Each exposed poly..., In a condensation reaction..., Two identical strands...)
1) DNA helicase breaks the H bonds linking base pairs
2) Double helix separates
3) Each exposed polynucleotide acts as a template to which complementary free nucleotides bind by specific base pairing
4) In a condensation reaction, DNA polymerase joins the nucleotides to form 'missing' polynucleotide strands
5) Two identical strands of DNA formed, semi-conservative replication
Describe the structure of ATP
- Adenine is the nitrogen-containing organic base
- Ribose is the pentose sugar
- Triphosphate
What is the symbol equation for the hydrolysis catalysed by ATPase?
ATP + H20-> AD + Pi + E
During what kind of reaction is ATP synthesised? And what catalyses it?
Condensation reaction, ATP synthase
What are the 5 roles of ATP?
- Metabolic processes
- Movement (muscular contractions)
- Active transport
- Secretion
- Activation of molecules
Suggest why the bases A-G and C-T would not bind together
The linking of the new nucleotides wouldn't occur. While the nucleotides would match up to their complementary nucleotides on the original strand, they wouldn't join together to form a new strand