1. The structure and Function of Macromolecules

2. Macromolecules defined…
Large
Organic (made of carbon compounds)
4 Classes
Essential for life
Most are polymers (long chains of covalently-bonded building blocks called, “monomers”)
Form by dehydration (removing H2O)
Break apart by hydrolysis (adding H2O)

3. Overview: 1. Carbohydrates 2. Lipids Roles: fuel, building materials
Sugars
Roles: energy storage, cell membranes
Fats

4. Overview: 3. Proteins 4. Nucleic Acids
Speed up chemical reactions, structural support, storage, transport, cellular communication, movement, defense
Enzymes
Store and transmit hereditary information
DNA (deoxyribonucleic acid)

5. Carbohydrates

6. Carbohydrates Monomers: MONOSACCHARIDES Multiples of the unit CH2O
Key features:
Carbonyl group (>C=O)
Hydroxyl groups (-OH)
Aldose (aldehyde: =O on end) or Ketose (ketone: =O in middle)
names end in “-ose”
Most form rings in aqueous solutions

7. Carbohydrates
Monosaccharides - Major nutrients for cells and raw material for small organic molecules
Disaccharides – joined by glycosidic linkage (sucrose = glucose + fructose)
Polysaccharides – macromolecules, 100’s to 1,000’s, ex. = starch (energy storage in plants) and glycogen (energy storage in animals), cellulose (plant cell walls), chitin (arthropod exoskeletons)

8. Lipids

9. Lipids Do not consist of polymers Little or no affinity for water
Three kinds -
1. Fats: Energy Storage
Consist of glycerol (alcohol with 3 C’s) and fatty acids (long hydrocarbon chain with a carboxyl group on one end) O=C-OH
Triacylglycerol = 3 FA molecules joined to a glycerol by an ester linkage
Saturated – no double bonds, pack tightly, room temp., animal fat; Unsaturated = at least 1 double bond, pack less tightly, room temp, plant fats

10. Lipids Three kinds (continued) - 2. Phospholipids: Cell Membranes
Only 2 FA’s attached to a glycerol (hydrophilic head & hydrophobic tail)
Bilayers shield hydrophobic regions from water
3. Steroids
4 fused rings (with varying functional groups)
Ex. = cholesterol – a component of animal cell membranes, precursor for other steroids (such as hormones)

11. Proteins

12. Proteins Many different functions (named earlier)
Enzymes are very important
Catalysts – speed up chemical reactions without being consumed
Structures are diverse
20 different Amino Acids = building blocks
Each has an amino group (N), a carboxyl group (O & OH), and an “R” group
Can be Nonpolar (hydrophobic), Polar (hydrophilic), or Charged (acidic/basic)
Many amino acids = polypeptide; 1 or more polypeptides folded into a unique shape = protein
Peptide bonds join amino acids together

13. Proteins 4 Levels of Protein structure:
1. Primary – sequence of amino acids; like order of letters in a word
2. Secondary – coils/folds in protein structure; alpha helix, beta pleated sheet; results from interactions of the polypeptide backbone (H and O)
3. Tertiary – overall shape resulting from interactions between R groups (side chains); hydrophobic interactions, disulfide bridges (sulfhydryl groups –SH bond)
4. Quaternary – 2 or more polypeptide chains aggregated into one functional macromolecule; example: hemoglobin (has 4 subunits)

14. Proteins
Changes in Conformation: when shape is changed, ability to function changes; Example: sickle cell disease (abnormal hemoglobin  deformed blood cells blood clots)
Denaturation – unraveling of protein due to pH, salt, temperature, etc.
Chaperonins – proteins that assist with folding other proteins

15. Nucleic acids

16. Nucleic acids
Instructions for building proteins is found in genes, which consist of DNA
DNA: deoxyribonucleic acid
Genetic information inherited from parents
Bound in structures called, “chromosomes”
Sugar, phosphate, base  “nucleotide” building blocks
Ribose/deoxyribose = sugar
Pyrimidine (5C ring) (C,T) / purine (6C ring) (A,G) = base
Complimentary bases: Cytosine-Guanine; Thymine-Adenine
Found in nucleus of cells
Double helix
Strand direction is 5’ to 3’, antiparallel strands (like a highway)

17. Nucleic acids RNA: ribonucleic acid
mRNA = a copy of the DNA code that interacts with protein- synthesizing machinery (“ribosomes”) to make a polypeptide
Single stand
Uracil instead of Thymine