Nucleic Acid Structure & Function Part 1

-describes the flow of information from the heredity material (dsDNA to protein) via an RNA intermediate

informational biomolecules that store and transmit genetic (hereditary) information.
-occur as large un-branched polymers of nucleotides, RNA and DNA

Transcription

Translation

Reverse Transcription

DNA and RNA

False, because some viruses, RNA (via reverse transcription) or single stranded DNA (ssDNA) = hereditary material

-monomeric building blocks of all nucleic acid polymers
Consists of
-a nitrogenous heterocyclic base (purine or pyrimidine)
-Pentose sugar (ribose (RNA) or deoxyribose (DNA) )
-Phosphoric acid group in ester linkage to the 5' carbon of the pentose (phosphate)

-Acids
-neutral pH
-have 2 negative charges on phosphate

adenosine; (deoxy?)adenylic acid; AMP; dAMP

3; 4

position 1 carbon of the sugar through a beta-N-glycosidic bond
-attached to nitrogen one of pyrimidine & number 9 of purine

think "two rings" so...
-pyrimidine + 5 member imidazole ring
-Adenine & guanine

4-thiouracil
dihydrouracil
6 mercaptopurine

those that have been modified by the addition of a methyl (CH3) group

1) amino-acycl tRNA synthetase/tRNA recognition
2) tRNA/codon recognition
3) peptide synthesis by the ribosome

1) regulation of gene transcription
2) mRNA translation

1) gene expression
2) protection of DNA from endonuclease digestion

5-methyl-C
5-hydroxymethyl-C
6-methyl-A
2-methyl-G
7-methyl-G

-contain N atoms at position 1 & 3 of a 6 member ring
-cytosine, thymine (DNA), and uracil (RNA)

-pentose sugar, comprised of 5 C atoms
-found in RNA
-hydroxyl group (OH) attached to 2' carbon

-pentose sugar
-found in DNA
-OH group attached to 2' carbon is replaced by a H group

pentose sugar (ribose or deoxyribose) + nitrogenous base

1) precursors or substrates of nucleotides for RNA & DNA synthesis
2) ATP: universal chemical energy
3) GTP: protein synthesis
4) UTP: biosynthesis of glycoproteins
5) CTP: phospholipid biosynthesis
6) Formation of coenzymes (i.e. Pyridine & flavin)

CTP

UTP

ATP

GTP

the formation of a phosphodiester bond btw the 3'OH group of the dexoyribose/ribose on the last nucleotide of the dNTP/NTP precursor

cleave of the triphosphate, 2 phosphates are released

responsible for sealing nicks in DNA during replication and repair

via condensation reaction, water is released when phosphate of NMP attaches to 3'OH
-ATP is the energy source for this reaction

Rosalind Franklin & Wilkins

Rosalind Franklin

hydrolysis experiments

Sea Urchin: A
Yeast: T
E.Coli: G & C

E.coli: A & T
Sea Urchin: G & C

1) 2 polynucleotide complementary chains wrapped around each other in a right-handed double helix
2) the two chains are antiparallel --> one strand is 5' to 3', another is 3' to 5' held together by hydrogen bonds A=T C---G
3) sugar-phosphate backbones are on the outsides of the double helix, with the bases oriented inside toward the central axis
4) the planes of sugars are about at right angles to those of the bases
5) external diameter of helix is 2nm containing 10.4 base pairs per turn of helix (3.4nm)
6) has a major and minor groove, which proteins can interact and make contact with bases aka (DNA-protein binding sites)
7) stabilization of helix achieved by H bonds, stacking interactions (van der Waals forces) of the bases, hydrophobic effects and charge effects

perpendicular

True

10 bases

6 x 10^9 base pairs/human cell x 0.34 x 10^-9 m (apart) = 2 meters long