1. Biological Molecules – DNA & RNA
main functions of DNA (deoxribonucleic acid):
1. makes up chromosomes and genes (section of
DNA that codes for a specific protein)
2. controls all cell activities including cell division and
protein synthesis
3. undergoes mutations which are important to
process of evolution
main functions of RNA (ribonucleic acid):
*works with DNA to direct protein synthesis

2. Biological Molecules – DNA & RNA
Nucleotide:
5-carbon sugar (deoxyribose or ribose), phosphate, nitrogen-containing base
(monomer)
(1 ring = pyrimidine, 2 rings = purine)

3. Biological Molecules – DNA & RNA
DNA sugar:
DNA sugar:
DNA sugar:
deoxyribose
RNA sugar:
ribose

4. Biological Molecules – DNA & RNA
DNA Nitrogenous bases:
adenine
guanine
thymine
cytosine
purines
pyrimidines
RNA Nitrogenous bases:
uracil replaces thymine

5. Biological Molecules – DNA & RNA
DNA & RNA complementary base pairing:
*hydrogen bonding
adenine
thymine
(uracil)
guanine
cytosine
2 bonds
3 bonds

6. Biological Molecules – DNA & RNA
DNA Structure:
- 2 antiparallel strands of nucleic acids in nucleus
- each strand has a backbone of sugars + phosphates
of joined nucleotides
- bases stick out, hydrogen-bond with complementary
bases of other strand
- 2 strands wind around each other forming double helix

7. Biological Molecules – DNA & RNA
RNA Structure:
- single strand of nucleic acid, formed off a DNA
template in nucleus
- migrates to cytoplasm during protein synthesis

8. Biological Molecules – DNA & RNA
ATP:
adenosine triphosphate
- nucleotide used as primary carrier of energy in cells
- adenine base + ribose + 3 phosphates
- bond between outer 2 phosphates very high in energy:
when broken, much energy released, can be used by cell
(e.g. muscle contraction)
- bond between 1st/2nd phosphate also high in energy, not
as high as between 2 end phosphates
- ATP mostly produced inside mitochondria during process
of cellular respiration
high energy phosphate bonds