| Term | Definition |
|---|
| Nucleic Acid | polymer of nucleotides linked together via phosphodiester bonds between the 5'-OH of one pentose sugar and the 3-OH of an adjacent sugar |
| Purines | A and G (two cyclic structures) |
| Pyramidine | C, T, U (one cyclic structure) |
| Biological Functions of Nucleotides | 1. High energy compounds (ATP) 2. Cell communication (second messengers) 3. Carrier Molecules 4. structural components of coenzymes (NAD/FAD require ATP) |
| ATP has the ____ energy as any other nucleotide triphosphate | same |
| What do second messengers do (cAMP/cGMP) | help with hormonal responses |
| How is the double helix formed? | two polymers bound together by H-Bonds |
| 5 features of the double helix | 1. nucleic acid chains run in opposite directions 2. nitrogen bases are located inside the helix, sugar and PO4 are on the outside 3. diameter of the helix is 20A, bases seperated by 3.4 A, 10 bases/turn 4. Strands held together by hydrogen bonds 5. sequence of bases determine genetic information |
| B DNA | major form in the cell. right handed helix, hydrated |
| A DNA | less hydrated, right handed helix, shorter and more diameter |
| Z DNA | left handed helix, small diameter, longer |
| _____ and ____ of DNA increases with the evolutionary scale | size and amount |
| Denaturing agents of DNA | 1. pH 2. heat 3. decrease in dielectric constant 4. urea and other solvents |
| Hyperchromic effect | absorbs higher amount of light when strand is seperated |
| Melting (Tm) | seperation of two strands |
| Which nucleotides increase the melting point? | G and C because they have triple bond |
| Supercoiling | twisting of closed circular DNA (some linear can do this too) |
| Functions of Supercoiling | 1. Package DNA in smaller area (nucleus) 2. Promotes Strand separation |
| Positive coiling | clockwise |
| Negative coiling | counterclockwise |
| Linking # | more twists = higher number (not # of twists) |
| Topoisomerases | enzymes that control state of super coiling, such as relaxing |
| Topoisomerase I | Relaxes supercoil by forming ss breaks, binds to DNA and allows swivel |
| Topoisomerase II | Removes supercoils by adding opposite type of coil (positive -> negative), ds break |
| Why is DNA considered an acid? | phosphate bridges (phosphoric acid donates proton) |
| Phosphates attached to ATP have what pka | 4 |
| How is ATP stabilized? | Mg and Mn stabilize with + charge |
| P/\P/\P/\Adenosine | gamma, beta, alpha (gamma phosphate removed very easily) |
| Griffeths's Experiment | smooth = virulent rough=nonvirulent, heated virulent strain inject into mouse =lives, living nonvirulent + heatkilled => mouse dies due to transformation |
| Avery | found out DNA was molecule transformed, by adding enzymes to degrade transforming element, and when DNAse was added it didn't result in dead mouse |
| Hershey Chase Experiment | viral particles when labeled with 35SO4 (protein) or 32PO4 (DNA), only the PO4 label entered the host cell |
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