Compare and Contrast DNA & RNA & DNA Replication

DeoxyriboNucleicAcid- 

 1. Definition: A nucleic acid that contains the genetic instructions used in the development an functioning of all modern living organisms.
 2. Job/Role: Medium of long-term storage and transmission of genetic information.
 3. Unique Features: The helix geometry of DNA is of B-Form. DNA is completely protected by the body, i.e., the body destroys enzymes that cleave DNA. DNA can be damaged by exposure to Ultra-violet rays.
 4. Predominant Structure: Double-stranded molecule with a long chain of nucleotides.
 5. Bases & Sugars: Deoxyribose, sugar; phosphate backbone; Four bases: adenine, guanin, cytosine and thymine.
 6. Pairing of Bases: A-T (Adenine-Thymine), G-C (Guanine-Cytosine)
 7. Stability: Deoxyribose sugar in DNA is less reactive because of C-H bonds. Stable in alkaline conditions. DNA has smallet grooves, which makes it harder for enzymes to "attack" DNA.
 8. Propagation: DNA is self-replicating.

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RiboNucleicAcid-

 1. Definition: A single-stranded chain of alternating phosphate and ribose units with the bases Adenine, Guanine, Cytosine, and Uracil bonded to the ribose. RNA molecules are involved in protein synthesis and sometimes in the transmission of genetic information.
 2. Job/Role: Transfer the genetic code needed for the creation of proteins from the nucleus to the ribosome.
 3. Unique Features: The helix geometry of RNA is of A-Form. RNA strands are continually made, broken down and reused. RNA is more resistant to damage by Ultra-violet rays.
 4. Predominant Structure: A single-stranded molecule in most of its biological roles and has a shorter chain of nucleotides.
 5. Bases & Sugars: Ribose sugar; phosphate backbone. Four bases: Adenine, Guanine, Cytosine, and Uracil.
 6. Pairing of Bases: A-U (Adenine-Uracil), G-C (Guanine-Cytosine)
 7. Stability: Ribose sugar is more reactive because of C-OH (hydroxyl) bongs. Not stable in alkaline conditions. RNA has larger grooves, which makes it easier to be attacked by enzymes.
 8. Propagation: RNA is synthesized from DNA when needed.

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DNA Replication

The double helix of the DNA unwinds. Then, the enzyme helicase 'unzips' the DNA by breaking the hydrogen bonds. Then, the enzyme DNA Polymerase pairs each of the two strands with the correct nitrogenous bases. The top strand is called the 'leading strand' and the bottom strans is called the 'lagging strand'. Then the enzyme ligase glues together the different fragments of the lagging strand of DNA. Now we have tow exact replications of DNA, each with 46 chromosomes called daughter cells.