AP Biology 2005-2006 Chapter 5. Macromolecules. AP Biology 2005-2006 Macromolecules Smaller organic...

AP Biology 2005-2006

Chapter 5.

Macromolecules


Macromolecules Smaller organic molecules join together

to form larger molecules macromolecules

4 major classes of macromolecules: carbohydrates lipids proteins nucleic acids


Polymers Long molecules built by linking chain

of repeating smaller units polymers monomers = repeated small units covalent bonds


How to build a polymer Condensation reaction

dehydration synthesis joins monomers by “taking” H2O out requires energy

& enzymes


How to break down a polymer

Hydrolysis use H2O to break apart monomers

reverse of condensation reaction

H2O is split into H and OH


Carbohydrates


Carbohydrates Carbohydrates are composed of C, H, O

Function: energy energy storage raw materials structural materials

Monomer: sugars

ex: sugars & starches


Simple & complex sugars Monosaccharides

simple 1 monomer sugars glucose

Disaccharides 2 monomers sucrose

Polysaccharides large polymers


Polysaccharides Function:

energy storage starch (plants) glycogen (animals)

building materials = structure cellulose (plants) chitin (arthropods & fungi)


Lipids


Lipids Lipids are composed of C, H, O

long hydrocarbon chain Diverse group

fats phospholipids steroids


Fat Triglycerol

3 fatty acids linked to glycerol


Fats Long HC chain

non-polar hydrophobic

Function: energy storage cushion organs insulates body


Saturated fats All C bonded to H No C=C double bonds

long, straight chain most animal fats solid at room temp.


Unsaturated fats C=C double bonds in the fatty acids

plant & fish fats vegetable oils liquid at room

temperature


Phospholipids Structure:

glycerol + 2 fatty acids + PO4


Phospholipids & cells Phospholipids of cell membrane

double layer = bilayer hydrophilic heads on outside hydrophobic tails on inside forms barrier between cell &

external environment


Steroids ex: cholesterol, sex hormones

cholesterol


Cholesterolhelps keep cell membranes fluid & flexible


Proteins


Proteins Most structurally & functionally diverse

group of biomolecules Function:

involved in almost everything enzymes structure (keratin, collagen) carriers & transport (membrane channels) receptors & binding (defense) contraction (actin & myosin) signaling (hormones) storage (bean seed proteins)


Proteins Structure:

monomer = amino acids 20 different amino acids

polymer = polypeptide complex 3-D shape


Amino acids Structure:

central carbon amino group carboxyl group (acid) R group (side chain)

variable group confers unique

chemical properties of the amino acid —N—

H

H

H|

—C—|

C—OH

||O

R


Protein structure & function

hemoglobin

function depends on structure 3-D structure

twisted, folded, coiled into unique shape

collagen

pepsin


Primary (1°) structure Order of amino acids in chain

A long ribbon


Secondary (2°) structure “Local folding”

Hydrogen bonds between R groups

-helix (spiral) -pleated sheet

(pleats)


Tertiary (3°) structure “Whole molecule folding”

Hydrogen bonds


Quaternary (4°) structure Joins together more than 1 polypeptide chain

only then is it a functional protein

hemoglobin

collagen = skin & tendons


Denature a protein Disrupt 3° structure

pH salt temperature

unravel or denature protein “change the shape, change the function”

Some proteins can return to their functional shape after denaturation, many cannot


Chapter 5.

Macromolecules: Nucleic Acids


Nucleic Acids Function:

store & transmit hereditary information

Examples: RNA (ribonucleic acid) DNA (deoxyribonucleic acid)

Structure: monomers = nucleotides


Nucleotides 3 parts

nitrogen base (C-N ring) pentose sugar (5C)

ribose in RNA deoxyribose in DNA

PO4 group


Types of nucleotides 2 types of nucleotides

different Nitrogen bases purines

double ring N base adenine (A) guanine (G)

pyrimidines single ring N base cytosine (C) thymine (T) uracil (U)


RNA & DNA RNA

single nucleotide chain Ribose sugar A, U, C, G

DNA double nucleotide chain Deoxyribose sugar A, T, C, G

AP Biology

Macromolecule Summary Carbohydrates

Monomers=monosaccharides Polymers=polysaccharides Used for energy, ex. Sugar

Lipids=fats=triglycerides Monomers=glycerol + 3 fatty acids Polymers=triglycerides Used for energy, ex. Steroids, cell

membranes

2005-2006

AP Biology

Macromolecule Summary Nucleic Acids

Monomers=nucleotides Polymers=nucleic acids Store genetic information, ex. DNA, RNA

Proteins Monomers=amino acids Polymers=polypeptides Used for growth, transport,

communication, ex. hair, nails, enzymes

2005-2006

AP Biology 2005-2006 Chapter 5. Macromolecules. AP Biology 2005-2006 Macromolecules Smaller organic...

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