- Nucleotides
- Provide the energy currency of cells in the form of adenosine triphosphate (ATP). Also provides the building blocks for inheritance in the form of DNA / RNA. A nucleotide is the sugar phosphate backbone and an organic nitrogenous base
- Nitrogenous Bases
- They are the purine pairs, most commonly found as adenine and guanine / cytosine and thymine.
- Purine
- It is two rings which contain nitrogen. Purine is a general term for some nitrogenous bases. Examples include adenine and guanine
- Pyrimidine
- It is one ring which contains nitrogen. Pyrimidine is a general term for some nitrogenous bases. Examples include cytosine, thymine and uracil
- Phosphate
- PO43- is part of the nucleotide. It is present in the cytoplasm of every cell. Nucleotides are acidic and carry a negative charge due to the phosphate group
- Pentose Sugar
- The sugar and phosphate are part of the nucleotide. They are joined by a condensation reaction.
- Double helix
- The iconic structure from which the sugar phosphate backbone has purine / pyrimidine base pointing inwards which causes the spiral pattern
- Anti-parallel
- The sugar phosphate backbones run against one another (one runs upwards the other downwards)
- Hydrogen bond
- The strands of DNA are held together between the complementary base pairs
- Obligate intracellular parasites
- OIPs cannot reproduce outside of the host cell, it is entirely dependent on the host cells resources
- Capsid
- The whole protein coat of viruses
- Capsomeres
- A sub unit of the capsid and can self – assemble
- Virus Attachment Particles
- Protein receptors on the edge of the virus that can attach to the host cell to inject DNA
- DNA
- The codes for protein in a normal cell / virus
- RNA
- Single stranded complimentary DNA
- Single strand RNA ssRNA
- A strand of RNA which is either positive or negative
- Positive - sense ssRNA
- RNA that can be immediately translated into viral proteins at the ribosomes
- Negative- sense ssRNA
- This is RNA that can’t be read so has to be transcribed into mRNA to make viral proteins
- RNA retroviruses
- Viruses that use reverse transcriptase
- Reverse transcriptase
- The enzyme converts RNA into DNA
- Latency
- Is the dormant period for a virus in which it grows and
- Lytic Pathway
- When the virus utilises the cell resources to construct viral proteins to make new viruses
- Provirus
- Is the viral DNA that is integrated into the host cell’s DNA
- Lysogenic Pathway
- DNA virus that is integrated into the host DNA which then is replicated as the cell reproduces and stops the viral proteins being created
- Virulent
- Disease causing