1. DNA, RNA & PROTEINS Part 1
The molecules of life

2. Roles of DNA: Store, Copy and Transmit Information
DNA provides the instructions for an organisms structure and characteristics
DNA can be copied to make new cells that are identical to the original cell (Replication)
Roles of DNA: Store, Copy and Transmit Information
RNA (Nucleic Acid used for making protein)
Transcription
Translation
Protein synthesis
Amino acids

3. DNA
Deoxyribonucleic Acid (DNA) is the blueprint for life: contains ALL the necessary information to make a new organism

4. DNA structure DNA is a polymer of nucleotides
Each nucleotide composed of
a phosphate,
a sugar (deoxyribose),
and organic nitrogenous base.

5. Four DNA bases Four kinds of nitrogenous bases: Purine bases
A = Adenine
G = Guanine
Pyrimidine bases
T = Thymine
C = Cytosine

7. DNA: Complimentary base pairing
Adenine pairs with Thymine
A T
Cytosine pairs with Guanine
C G

9. Each DNA strand is a compliment of the other
Original strand Matching copy
A T
C G
G C
T A

10. DNA STRUCTURE DNA is a double helix Discovered by
Watson and Crick, 1953

11. DNA structure

12. Antiparallel Strands

13. DNA REPLICATION (in the nucleus)
Each DNA strand
becomes a template,
parent strand becomes apart
Proper base-pairs are
assembled on that template
(with proper enzymes:
polymerase and ligase).
There’s always a pool of
nucleotides (A,C,T,G) in the nucleus

14. Semi-Conservative Replication
½ of the original is “conserved” and the other half is “new”

15. RNA structure and synthesis
RNA: Ribonucleic Acid
Is very similar to DNA
(repeating subunits, nucleotides).
Difference between RNA and DNA:
Each nucleotide contains a different sugar
(ribose instead of deoxyribose)
Bases are A, G, C, and U (uracil, not thymine)
A pairs with U; G pairs with C

16. RNA RNA is single stranded and shorter RNA is less stable than DNA:
RNA doesn’t persist in the cell for long (sometimes it exists for a few seconds),
whereas DNA can persist for the life of the cell.

17. Protein Synthesis DNA RNA Proteins
transcription
DNA
RNA
Proteins
3 different RNA molecules involved in protein synthesis:
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
translation