Functional Groups and macromolecules

Almost all chemicals of life are carbon based ◦ Except water

Compounds containing carbon are referred to as organic compounds ◦ Except carbon gases such as CO2

Organic compounds where originally believed to be made through biological processes ◦ Petrochemical and bioengineering now make a

variety of organic compounds

Carbon is able to make four stable covalent bonds with other atoms

The symmetry of bonding makes most molecules non-polar

Molecules composed solely of carbon and hydrogen

Other organic compounds contain one or more extra element in a functional group

Small groupings of elements, normally found near the end of a large organic molecule, that gives the molecules special reactive/bonding properties

normally composed of H, O, P, N and S

These groups are mainly polar and will make that end of the molecule more reactive and able to form new bonds

Aspirin

Try practice on pg. 27

Large Repeating subunits (usually) Four classes ◦ Lipids, carbohydrates, proteins, nucleic acids

Polymers (c, p, na) ◦ Assembled via energy absorbing condensation

reaction (dehydration synthesis) – anabolic reaction!

◦ Broken down into subunits (catabolic reaction) via hydrolysis, releasing energy

◦ Both of these use enzymes to make reaction more efficient

Produced via photosynthesis

Used by organisms for energy, building materials, id markers (e.g. blood types)

C:H:O ratio 1:2:1

Mono, oligo, and polysaccharides

“ose” ending ◦ triose, pentose, hexose

Isomers same formula different shape

Mono - glucose, ribose, fructose, galactose

Oligo – maltose, sucrose, lactose

Poly – glycogen (branched), cellulose (straight), chitin (straight), starch (amylose – straight, amylopectin – branched)

Storage ◦ Animals – glycogen Stored in muscle and liver, 1 day supply

◦ Plants – starch Plants produce more glucose than necessary for their needs,

chloroplasts make starch, stored in plastids, tubers, taproots and grain fruits

Consumed by animals for food

Structure ◦ Plants – cellulose Plant cell walls (most abundant organic substance on Earth!) Usefulness to us – clothing, wood and paper products, Requires bacteria for breakdown (cows, sheep, rabbits…) Fibre!!!

◦ Animals – chitin (insect and crustacean exoskeletons), fungi Usefulness to us – contact lenses, biodegradable stitches

C, H, O Hydrophobic - more non-polar bonds than

carbs ◦ Insoluble in water, soluble in non-polar substances

Used for storing energy, building cell parts, and for signaling

4 families ◦ Fats, phospholipids, steroids, waxes

Twice the energy storage of carbs

Excess carbs are stored as fats in animals and plants ◦ Triglycerides – ester linkages

Saturated vs. unsaturated

Animal vs. plant fats

Saturation allows for more intermolecular bonding, therefore solid at room temperature

Hydrogenation of plant oils

Margarine vs. butter vs. oil debate!

Cell membranes Phosphate, glycerol, 2

fatty acids Polar head

(hydrophilic), non-polar tails (hydrophobic)

Micelles Lipid bilayers ◦ proteins and pores

required for charged substances to pass through non-polar tails

4-Ring structures with functional groups

E.g. Cholesterol ◦ Atherosclerosis – plaque (fatty deposits) in arteries

blocks blood flow

◦ Converted into vitamin D and bile salts

E.g. Sex hormones – estrogens, testosterone, progesterone

Fatty acids linked to alcohol or carbon rings

Hydrophobic ◦ Waterproof coatings

Cutin (cuticle) on plant surfaces

Birds, bees, …

Most diverse and important molecules

DNA codes for proteins

Uses ◦ Enzymes – reactions at life-sustaining speeds

◦ Immunoglobulins - protection

◦ Transport – membrane proteins, hemoglobin

◦ Structure – keratin in hair and nails, fibrin in blood clots, collagen in bones/skin/etc.

Amino acid polymers folded into 3D shapes ◦ Amino acid – R group, carboxyl group, amine

group 20 different amino acids 8 essential amino acids – not synthesized by body

◦ Conformation is determined by amino acid sequence (polypeptide) Linkage between amino acids is called peptide bond Also formed by condensation reaction Amino group at one end (A-terminus), carboxyl group at

the other end (C-terminus)

◦ Polypeptide is made in cytoplasm via protein synthesis, according to DNA instructions

Meet the amino acids – pg. 42

Linear or sheet proteins - structural

Globular proteins – enzymes/functional ◦ Primary structure – aa sequence, one change can alter

function (eg. Sickle cell anemia) ◦ Secondary structure – coils and folds in the original aa

chain due to H bonds, alpha helix or beta pleated sheet ◦ Tertiary – environmental forces that cause additional

folding (eg. Hydrophobia, polar/non-polar R groups) A polypeptides final shape

H bonds, ionic bonds, van der Waals forces, disulfide bridges

◦ Quaternary – clustering of 2 or more polypeptides A proteins final shape

Determined by primary structure and environment

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/Denaturing.gif

Proteins are made in a certain environment Temp, pH, ionic [ ], etc. can change shape

(denature) H bonds, ionic bonds, disulfide bridges etc. will all

return to normal once change is reversed in small proteins

Chaperone proteins aid in folding Peptide bonds will not be remade however, so if

that occurs, protein is irreparably damaged Useful denaturation ◦ Gastrin denatured by SI pH ◦ Salt, sugar, vinegar denature food spoiling enzymes ◦ Blanching denatures browning enzymes ◦ Heat denatures hair proteins for shape changes ◦ Cooking meat for easier eating