DNA replication Flashcards
What is a nucleosome?
A length of DNA wrapped around a core of 8 histones
What is the function of a nucleosome?
To supercoil DNA in order to fit in the nucleus
What type of bond occurs between base pairs in DNA?
Hydrogen Bonding
Helicase function?
Unwinds DNA double helix
Single strand binding proteins function?
Keep the two strands separated during the replication process
DNA Gyrase function?
Relieves the tension of the supercoiling
DNA Polymerase III Function?
Adds DNA nucleotides to the strands
DNA Ligase function?
Joins the short DNA fragments together
DNA Primase function?
Makes RNA primers
DNA Polymerase I Function?
Removes RNA Primers and replaces it with DNA segments
What are Okazaki Fragments?
Short segments with gaps that are later joined together by DNA Ligase
Explain the process of DNA replication.
- Helicase unwinds the DNA double helix strand
- DNA Gyrase relieves the tension of the supercoiling
- Single strand binding proteins keep the two strands separated
- DNA Primase adds RNA primers that are complementary to the copied DNA.
- DNA Polymerase III adds DNA nucleotides to the growing DNA strands.
- DNA Polymerase I removes RNA primers and adds DNA segments.
- DNA Ligase joins the okazaki fragments together
What are some functions of non-coding DNA?
- Regulators of gene expression
- Introns
- Telomeres
- Genes for Trna
What are telomeres?
They are located on each end of a chromosome. The polymerase cannot add nucleotides in that area of the chromosome, so it is non-coded and known as telomeres.
Who discovered the structure of DNA?
Rosalind Franklin, she found that DNA was a helix made of a double-strand through X-ray diffraction, with the help of Crick and Watson.
