IntroNucleicAcids Flashcards
<p>What are the pyrimidines?</p>
<p>Cytosine
Uracil
Thymine</p>
<p>What are the Purines?</p>
<p>Adenine
| Guanine</p>
<p>How do Phosphodiester bonds form in DNA synthesis?</p>
<p>5 —> 3
5’ end of incoming nucleotide attacks 3’ hydroxide group</p>
<p>How is Base sequence of DNA written?</p>
<p>5’ —> 3’</p>
<p>What is Chargaff’s Rule?</p>
<p># Purines = # Pyrimidines
Due to H bonds only forming between specific base paring</p>
<p>What are the three main types of DNA structures?</p>
<p>B-DNA: Most common in normal cells
A-DNA: Water removed; More compact
Z-DNA: High C-G Base pairing; Left handed Helix; No major groove; Biological function unknown</p>
<p>What are the different types or RNA?</p>
<p>RRNA: Structural component of ribosome
TRNA: Carries AAs to ribosome
MRNA: Carries information to ribosome
HnRNA: mRNA precursor in nucleus
SmRNA: Splicing and removal of Introns
Ribozymes: RNA which acts as an enzyme</p>
<p>How does adenosine act as a neuromodulator? How is caffeine involved?</p>
<p>- Adenosine is a byproduct of ATP use and signals low energy
- Wakefulness neurons have A Adenosine receptors
- Sleepiness Neurons have A2A Receptors
- Caffeine is competitive inhibitor of adenosine receptors and decreases sensitivity of neurons</p>
<p>How does caffeine affect other organs in the body?</p>
<p>- decreases activity of A1 receptors in other organs
- Increases HR
- Increases Urine production</p>
<p>How many cAMPs are needed to bind PKA in Gs activation? and what kind of receptors use this method? And give expamples</p>
<p>4 cAMPs The catalytic subunit of PKA then phosphorylates other targets in a cascade effect. This is used by Beta-Adrenergic receptors. Glucagon or Epi stimulate Gs and lead to cAMP increase and glycogenolysis (breakdown of glycogen)</p>
<p>How is caffeine involved in breakdown of glycogen in the liver?</p>
<p>Coffee inhibits phosphodiesterase(cAMPs get inactivated by phosphodiesterase) —> Prolonged glycogen breakdown and small blood glucose boost</p>
<p>How does mitochondrial DNA differ structurally from nuclear DNA?</p>
<p>- Mitochondrial DNA has a circular structure</p>
<p>Differentiate Positive and Negative Supercoiling.</p>
<p>Positive: Wound more tightly; Faster gyrase; Lower cleavage
Negative: Wound more loosely; Slower gyrase; higher cleavage</p>
<p>What two amino acids are most common in histone proteins?</p>
<p>Arginine and Lysine</p>
<p>Which part of wound DNA is most sensitive to nuclease activity?</p>
<p>Naked linker DNA between each 10 nm bead</p>
<p>Differentiate how different nucleases cut polymers.</p>
<p>Exonuclease: Remove nucleotide from 5’ or 3’ end
Endonuclease: Cuts within nucleic acid and release fragments
Restriction endonuclease: Cut DNA specifically at palindromic sequences (DAN mapping cloning) </p>
Telomere structure and composition!
ends of chrom, provide a means to replicate the ends if linear chrom. Rich in C and G
