1.5 nucleic acids Flashcards
give the full names of both DNA and RNA
deoxyribonucleic acid and ribonucleic acid
what are DNA and RNA
polynucleotides
name and describe the three parts to DNA
- phosphate group
- nitrogenous base (ATGCU)
- pentose sugar (being deoxyribose or ribose)
what is the bond called and where is it between the two deoxyriboses bases
phosphodiester bond and connected by the phosphate group and C3
what are the 5 nitrogenous base names
Adenine, cytosine, thymine, guanine, uracil
what are the bonds between the nitrogenous bases
hydrogen bonds
which bases bond with each other in DNA
Adenine and thymine
cytosine and guanine
which bases bond with each other in RNA
adenine and uracil
cytosine and guanine
what are the two DNA replications and which one is true
conservative - 2 separate DNA strands from one original
semi-conservative - 2 new strands by splitting the original and having a new single stand on each one (half and half)
semi-conservative is the true way of it happening
model 6 marker on DNA replication
- DNA helicase unwinds the DNA by breaking hydrogen bonds
- Both strands act as templates
- Nucleotides line up in their complementary pairs of adenine with thymine and cytosine with guanine
- DNA polymerase joins nucleotides
- Forming phosphodiester bonds each new DNA molecule consists of one original template and one new molecule.
What new the two people called who proved DNA was semi-conservative and how did they do this
Meselson and Stahl
1. Had bacteria grow in ^15N leaving them to have ^15N nitrogenous bases
2. Centrifuge this solution and put it in a ^14N solution
3. These cells then replicate in the ^14N and become ^14N/^15N
4. These cells continue to replicate in the ^14N and as they are centrifuged they become lighter
this was proved as the ^14N bases are lighter so they were higher in the centrifuge than the hybrids which were also higher than the just ^15N bases.
