DNA Hybridization Flashcards
What is a pentose sugar?
→ 5 carbons that form a cyclical structure with an oxygen bridge
What are the pyrimidines?
→ Cytosine
→ Thymine
→ Uracil
What are the purines?
→ Adenine
→ Guanine
On what basis does hydrogen bonding form?
→ Watson and Crick base pairing
Between what two groups does bonding occur?
→ Purines and pyrimidines
How many hydrogen bonds are there between T and A?
→ 2
How many hydrogen bonds are there between C and G?
→ 3
Between what base pairs is hydrogen bonding the strongest and why?
→ C and G
→ 3 H bonds
What are sugar phosphates linked by?
→ phosphodiester bonds
What kind of interactions does base stacking involve?
→ hydrophobic interactions
Why are bases stacked?
→ To exclude water from the inside of the molecule around the bases
Describe what the Van der Waals forces are like in DNA?
→ Individually small but they contribute to the stability
What is the backbone of DNA formed by?
→ Phosphodiester linkage
What do phosphodiester bonds join?
→ 3 and 5 prime carbons of deoxyribose of DNA
What does the stability of DNA depend on?
→ Free energy of the molecule
→ Energy minimization
What do phosphate groups interact with?
→ proteins
What bonds can be broken to denature DNA?
→ Hydrogen bonds
What disrupts hydrogen bonding?
→ Alkalis
→ Heat
What is hyperchromicity?
→ Increased absorption of light at 260nm on denaturation
→single stranded DNA absorbs UV light to a greater extent than double stranded DNA
What is Tm?
The point at which 50% of all strands separate is called the melting temperature