DNA Structure Flashcards
What are the two types of Nucleic acid and what are the differences between them?
- DNA + RNA
- Deoxyribose sugar vs ribose sugar
What are the names of the 5 nucleotide bases?
- Adenine
- Thymine
- Uracil
- Guanine
- Cytosine
Which bases bond with each other?
- Adenine bonds with thymine (Uracil in RNA)
- Guanine bonds with cytosine
What are the pyrimidines and how many rings do they have?
- cytosine
- Thymine
- Uracil
- single ring
What are the purines and how many rings do they have?
- Adenine
- Guanine
- 2 rings
What is the name of the bonds that join nucleotide monomers?
Phosphodiester bonds
Explain the formation of the phosphodiester bond:
The Hydroxyl group (OH) on carbon 3 of one nucleotide reacts with the phosphate group attached to carbon 5 on another nucleotide
Which direction are DNA and RNA strands synthesized in?
5’-3’ direction
What is the name for the model of DNA replication?
Semi- conservative model of replication
What enzyme repairs replication errors during replication?
exonuclease
What enzyme repairs DNA replication errors after replication?
Endonuclease
What is the error rate of DNA polymerase III
1 in 10^8-10^10 base pairs
How does DNA pol III “proofread”
3’-5’ (of template strand) exonuclease activity of pol III removes incorrect bases during replication
How does DNA repair after replication occur?
- damage, including some flanking regions is removed by an endonuclease
- A DNA polymerase makes new DNA
- DNA Ligase joins ends of new stand with pre-existing strand
Why is correcting DNA errors so important?
- replication is semiconservative
- mistake becomes template strand
- newly replicated strand will also be incorrect
- All strands based off this template strand with continue to be incorrect
What are the Key details of the polymerase chain reaction (PCR) (4)
- in vitro method of making multiple DNA copies so that there is enough DNA material to work with
- Only targeted regions are copied
- causes rapid exponential increase of DNA molecules
- Utilizes heating and cooling to maximize enzyme activity
What are the uses of PCR? (4)
- Medical applications
- Forensic applications
- Infectious Disease detection and identification
- Molecular biology research applications
What are the basic steps of PCR?
- temperature increased to denature ( separate) DNA strands
- Temp decreased to allow primers to base pair to complementary DNA template
- Polymerase extends primer to form nascent DNA strand
- repeat up to 35 times
What are the differences in DNA replication in vivo and in vitro?
- in vivo has RNA primer, in vitro has DNA primer
- in vivo has primer synthesized by primase, in vitro has completed primer added
- in vivo has a leading and lagging (discontinuous) strand, in vitro has 2 continuous strands
- in vivo uses multiple enzymes and proteins, in vitro only uses heat stable DNA polymerase
