DNA Structure Flashcards
What is DNA?
What does it consist of? (the type of monomer)
A large molecule (macromolecule) that carries genetic information needed to synthesise proteins.
Nucelotides
What are some features of DNA?
- Helical
- Double stranded
- Wrapped around histones
- Consists of nucleotides with complementary base pairing
What is the importance of ‘Complementary base-pairing’?
- DNA remains orderly (shape stays intact)
- Strands can separate and bond together <- allows and EXACT copy to be made
Why are the Hydrogen Bonds between bases weak?
Allows DNA to unwind for replication
Explain the term ‘Antiparallel’
Where does the phosphate bond to?
DNA strands run in opposite directions.
FROM 5’, TO 3’
5’
Explain “Leading & Lagging” (in replication)
What is the role of primer?
What is it made of?
Initiate the formation of DNA (starting point). In “lagging”, it will create Okazaki fragments.
Primase (made of RNA)
Semi-conservative DNA
During replication, new DNA is formed from one OLD template strand, and one NEW strand made from free DNA nucleotides.
Steps for REPLICATION:
- Helicase, unzips
- Free nucleotides, attracted to open bases
- DNA Polymerase
Why does DNA need to replicate?
- Growth
- Repair/Maintainance
- Reproduction
All need DNA to function.
What are genes?
A segment of DNA which codes for a specific polypeptide chain.
Exons & Introns
Exons: are CODING parts of the gene, used for transcription.
Introns: are not needed for protein synthesis
