DNA Structure Flashcards
What is DNA composed of
2 long polynucleotide chains twisted into a double helix
What forms the sugar phosphate backbone
Pentose sugar + phosphate group
What are the strands of DNA held together by
Hydrogen bonds
Why is DNA said to be anti - parallel
Strands of DNA runs in opposite direction
What are the bases in DNA
Adenine, guanine, cytosine, thymine
What are the specific base pairs of DNA bases
A = T G = C
How many hydrogen bonds in A = T
2 Hydrogen bonds
How many hydrogen bonds in G = C
3 hydrogen bonds
Correct bases pair up due to
- number of hydrogen bonds each pair of bases form
- sizes of the bases
Chargaffs rule
Always be the same % of complementary bases in DNA molecule
A% = T%
What is the function of the phosphate backbone
- Strength and stability
- protects from chemical and physical damage
What is the purpose of DNA being double stranded
- allows for semi conservative replication
- both grands can be templates
What are the 3 part that make up the DNA
- phosphate group
- nitrogen containing organic base
- pentose sugar
What is the pentose sugar found in DNA
deoxyribose
Main function of DNA
DNA replication and store genetic info
