AP BIO 1.4 - 1.5

Carbohydrates

• found in grains, fruits, and vegetables

• Function: energy, structure, recognition, signaling

• contains no nitrogen and phosphorus

What are the 3 sub-types of carbohydrates?

monosaccharide, disaccharide, polysaccharide

monosaccharides

• simple sugars

• building blocks

• In clude hexoses: all have C6H12O6 with different isomers

  • Glucose - energy

  • Galactose - lactose

  • Fructose - fruit

dissaccharides

• 2 monosaccharides covalently bonded during condensation reaction

• forms glycosidic linkage

• i.e sucrose (glucose fructose) + maltose (glucose glucose)

polysaccharides

• long chain of monosaccharides

• may be branched/unbranched

starch

• type of polysaccharide

• stores plants’ energy

• branched

  • limits the number of H-Bonds that can form

  • less compact

Glycogen

• type of polysaccharide

• stores animals’s energy (liver and muscles)

• highly branched

  • makes solid deposits more compact than starch

Cellulose

• structures in plants (cell wall)

• linear

  • parallel cellulose molecules form hydrogen bonds

  • creates thin fibers

Chitin

• structure fungal cell walls, insect exoskeletons, and crustacean shells

• hard exoskeleton of arthropods

• Also contains Nitrogen

Lipids

• diverse group of non-polar hydrocarbons

• stores energy, provides insulation, cushioning, protection, serves as building blocks, in cellular membranes

Triglyceride

• 3 fatty acids (nonpolar hydrocarbon chain attached to a polar carboxyl group COOH) + 1 glycerol (an alcohol with 3 hydroxyl)

• involves three condensation reactions forming three covalent bonds known as ester bonds, releasing 3 water molecules.

Saturated fat

• “saturated” because it is saturated with H

• no carbon carbon double bond

• dense, pack tightly

• exist as solid in room temperature

• can cause cardiovascular diseases

Unsaturated fat

• contains at least 1 carbon carbon double bond

  • monounsaturated: 1 double bond

  • polyunsaturated: more than 1

• liquids @ room temp

• have a kink keeping them from being dense

cis vs trans fat

• cis fat has H on the same chain liquid, making the fat more bent → less dense

  • liquid

• trans fat has H on opposite chains, meaning it has no bends and kinks

  • solids, very very unhealthy

essential fatty acids

Essential fatty acids – required but not synthesized by the body – must be part of diet

• Omega-3 fatty acid (found in salmon, trout, tuna, and plants)

• Omega 6-fatty acid

These fats are heart healthy

waxes

• Long fatty acid chains esterified to long chain alcohols

• Hydrophobic and prevent water from sticking to surface

Phospholipid

• 2 fatty acids + a modified phosphate group attached to glycerol backbone

• modified by adding a charged/polar chemical group

• The hydrophilic head groups of the phospholipids face the aqueous solution

• The hydrophobic tails are sequestered in the middle of the bilayer

• Phospholipids contribute to dynamic nature of plasma membrane

Steroids

• closed ring structure

• 4 linked carbon rings

• short tail + hydrophobic

• Precursor, “exigence”, to other hormones such as testosterone and estradiol, cholesterol, bile salts