3.2 Macromolecules Notes IB Biology HL 1 Mrs. Peters Fall 2013

Macromolecules Polymer : a long molecule consisting of many similar or identical building blocks linked by covalent bonds  Ex: carbohydrates, proteins, nucleic acids

Polymers Polymers are made up of monomers  Monomers are small repeating units; the building blocks of polymers.  Ex: Glucose is a monomer, starch is a polymer: many glucose bonded together make starch. Glucose Starch

3.2.5 Condensation Reaction Condensation Reaction- building polymers  Two molecules are joined to form a larger molecule, held by covalent bonds ; requires an enzyme and produces one water molecule.  Each monomer contributes to water that is made, one provides the -OH, one the -H.  Also known as dehydration reaction

3.2.5 Condensation Reaction Condensation Example: Glucose + Galactose  Lactose + water (monomer) + (monomer)  (polymer) + water ** Lactose is really called a dimer (only two monomers are bonded together) Di- means 2 ** Polymer is for many monomers bonded together; Poly- means many

3.2.5 Hydrolysis Hydrolysis- How to break polymers into monomers bonds between monomers of a polymer are broken by the addition of water molecules ; requires enzymes  a H from water attaches to one monomer  OH from water attaches to the other monomer

3.2.5 Hydrolysis Hydrolysis Example: Lactose + water  Glucose + Galactose (polymer) + water  (monomer) + (monomer)

Classes of Macromolecules Carbohydrates Lipids Proteins Nucleic Acids

3.2.3 Monosaccharides Monosaccharides: simplest carbohydrates  simple sugars  General formula (CH 2 O) n  Major nutrients for cells  Serves as raw material for synthesis of other molecules  Used to make di saccharides and poly saccharides  Ex: glucose, fructose, galactose C 6 H 12 O 6

Monosaccharides **Glucose: energy source carried by the blood to cells **Fructose: used to make fruit sweet tasting and attractive to animals Galactose: used to make milk

3.2.2 Glucose Structure Draw a glucose molecule! (You must be able to ID this molecule from others!)

3.2.3 Disaccharides Disaccharides: two monosaccharides joined by a glycosidic linkage (covalent bond between monosaccharides using condensation)  Ex: sucrose; maltose; lactose

Disaccharides **Sucrose: glucose + fructose; carried by phloem to transport energy to cells in plants Maltose: 2 glucose; used in creating starch **Lactose: glucose + galactose ; the sugar in milk; source of energy

3.2.3 Polysacchrides Polysaccharides: storage and structural macromolecules made from a few hundred to a few thousand monosaccharides  Ex: starch, glycogen, cellulose

Polysaccharides Storage Polysaccharides  Starch : found in plants, polymer made of glucose molecules, used for energy  **Glycogen : found in animals, a highly branched polymer of glucose (short term energy storage in liver and muscle cells)

Polysaccharides Structural Polysaccharides  **Cellulose : used to make strong fibers; major components on plant cell walls Bioweb.wku.edu

Time to Build!! Practice condensation and hydrolysis reactions by building different types of carbohydrates.

3.2.6 Lipids Long term energy storage molecules in plants and animals Solids are known as fats; liquids are known as oils  Animals: store fat  Plants: store oils

3.2.6 Lipids Functions  Long term energy storage  Insulation  Buoyancy  Prevent water loss in plants

Types of Lipids Fatty Acid : a long hydrocarbon “tail” with a carboxyl group at the head end  Saturated: have no double bonds in the carbon chains  Unsaturated: have double bonds in carbon chains

3.2.2 Fatty Acid Structue Fatty Acid : Draw a fatty acid You must be able to ID it from others!

Types of Lipids Fat : Composed of a fatty acid attached to glycerol Triglyceride: Consists of three fatty acids linked to glycerol by condensation reactions Draw the general lipid Structure: Glycerol attached to one or more fatty acids

General Lipid Structure Draw the general lipid structure: Glycerol attached to one or more fatty acids

Types of Lipids Phospholipids : major components of cell membranes  Hydrophilic head  Two fatty acid tails (hydrophobic) Draw and label a phospholipid

3.2.7 Carbohydrates vs. Lipids Carbohydrates Easily digested, energy is released more rapidly Soluble in water, easy to transport Short term energy storage Stored as glycogen in animals and starch in plants Lipids Twice as much energy per gram than carbs, but harder to break down (slow process) Non-polar, insoluble Long term energy storage Lipid storage is lighter for same amount of carbs Used for insulation and buoyancy in animals

Time to build!! Practice condensation and hydrolysis reactions by building different types of lipids.

Proteins Functions :  Structural support  Storage (not of energy)  Digestion  Transport  Signaling  Movement  Defense  Hormones  Enzymes Function depends on structure and interactions of amino acids of polymer

Proteins Made up of amino acids Amino acid chains form polypeptides, based on a specific sequence and vary in length from a few to thousands Proteins consist of one or more polypeptides folded and coiled into specific formations

Amino Acids Amino Acid Structure: An amino group bonded to a central carbon bonded to a carboxyl group, an “R” group (some other functional group) bonded to the central carbon

3.2.2 Amino Acid Structure Amino Acid: Draw an amino acid You must be able to ID it from others.

Amino Acids Types of Amino Acids  20 different (don’t memorize)  Grouped by the properties of side chain  Non-polar side chains = hydrophobic  Polar side chains = hydrophillic

7.5.1 Protein Structure Four levels of Structure  Primary  Secondary  Tertiary  Quaternary

7.5.1 Protein Structure Primary Structure: polypeptide chain  Unique sequence of amino acids held together by a peptide bond  Created by condensation reactions (amino acids are monomers)  Chain can be 100’s of amino acids long  Primary structure determines the next three levels, a slight change in one amino acid can affect the protein’s form and function

7.5.1 Protein Structure Secondary Structure: Coiling and folding of the polypeptide  Created by H bonds between the oxygen in one carboxyl group and the hydrogen of an amino group

7.5.1 Protein Structure Secondary Structure  Types of structures  Alpha Helix: delicate coil held by H bonds between every fourth amino acid  Beta Pleated Sheet: two or more regions of polypeptide chains lie parallel to each other with H bonds holding structure together

7.5.1 Protein Structure Tertiary Structure: polypeptide bends and folds over itself.  Irregular contortions resulting in interactions between R groups of amino acids  Forms a definite 3D structure important in determining the specificity of the protein

7.5.1 Protein Structure Tertiary Structure  Types of bonds:  Disulfide bridges: strong covalent bond between sulfur atoms  H bonds between Polar side chains  Van der Waals: strong interactions between Hydrophobic side chains  Ionic bonds between + and – charged side chains

7.5.1 Protein Structure Quaternary Structure Overall protein structure  Involves multiple polypeptide chains combined to form a single protein structure  All types of bonds in other levels involved in this level also

7.5.2 Types of Proteins Two types of proteins  Fibrous  Globular

7.5.2 Types of Proteins Fibrous: composed of many polypeptide chains in long narrow shape, usually insoluble in water Ex: Collagen: connective tissue of humans Actin: component of human muscle, involved in contractions

7.5.2 Types of Proteins Globular: 3D in shape, mostly water soluble Ex:  Hemoglobin: delivers oxygen to body tissue  Insulin: involved in regulating blood glucose levels

7.5.4 Examples of Proteins Protein Function Hemoglobin (haemoglobin) Contains iron, transports oxygen in the body (transport) Actin and Myosin Interact in muscle contractions of animals ( movement ) Insulin Hormone that aids in the maintenance of blood glucose levels in vertebrates ImmunoglobulinsAct as antibodies to fight bacteria and viruses (defense) AmylaseDigestive enzyme that breaks up starch (digestion) PepsinDigestive enzyme that breaks down protein in stomach (digestion) CollagenStrengthens bone, component of tendons, ligaments and skin (structural)

Proteins Denaturation (break down) of proteins is caused by:  Change in pH  Salt concentration  Temperature  Other environmental aspects

Time to Build!! Practice condensation and hydrolysis reactions by building proteins. Create models of the four protein structures.

Nucleic Acids Types: DNA and RNA Made of repeating units of nucleotides Nucleotides created by a sugar, phosphate group and a nitrogen base. DNA contains deoxyribose sugar RNA contains ribose sugar

3.2.2 Ribose Structure Draw a Ribose molecule You have to be able to ID it from others.

3.2.2 Identify the following Glucose Ribose Fatty Acid Amino acid

3.2.5 Role of Condensation and Hydrolysis Describe how condensation