Biochemistry The Molecules of Life 4.1.1: Compare the structures & functions of the major biological molecules

Nutrition 101 Calorie = measurement of energy 4 calories to metabolize 1 g of protein 4 calories to metabolize 1g of carbs 9 calories to metabolize 1g of fat

Organic Compounds Organic chemistry is the study of all compounds that contain bonds between carbon atoms The four most important biomolecules we will study are: Carbohydrates Lipids Proteins Nucleic Acids

Carbon’s Bonding Behavior Valence shell has 4 electrons; can hold 8 Each carbon atom can form covalent bonds with up to 4 atoms

Bonding Arrangements Carbon atoms can bond with many different atoms and with itself in long chains or rings Other atoms can project from the carbon backbone

Macromolecules Many molecules are very large - macromolecules Large molecules are formed by joining smaller ones together Smaller units: Monomers Large units: Polymers (poly = many) Functional groups An atom or a group of atoms with characteristic properties that is covalently bonded to the carbon chain in an organic molecule. Changes the chemical behavior of the molecule.

Carbohydrates Carbohydrates function as short-term, accessible energy Complex carbs vs. Simple carbs Fiber & starch vs. sugar Carbohydrates come in three basic types: Monosaccharides Oligosaccharides (including disaccharides) Polysaccharides Fiber- complex, insoluble vs. soluble Starch- complex Sugar- simple, often stored as fat b/c mostly fructose which can only be used by the liver, changes blood sugar can lead to type 2 diabetes

Monosaccharides glucose fructose Simplest carbohydrates Have 5- or 6-carbon backbone Sweet taste Water soluble C,H,O glucose fructose

Disaccharides Type of oligosaccharide Greek for “few” Two monosaccharides covalently bonded Formed by condensation reactions H2O is a biproduct + H2O glucose fructose sucrose

Polysaccharides Straight or branched chains of many sugar monomers Cellulose Starch Glycogen

Lipids (Fats) Formed from a glycerol and fatty acids (most of the time, except in steroids) Insoluble in water C,H,O Monomer= fatty acid Carboxyl group Saturated: single bonds between carbons Unsaturated: one or more double bonds

Fats: Good or Bad? Saturated fats: Unsaturated fats: Recommended consumption= less than 10% of calorie intake Raises bad cholesterol higher risk of heart disease Ex: butter, processed meats, peanuts, whole milk, fried food, white flour Unsaturated fats: Recommended consumption= less than 30% of calorie intake Raises good cholesterol, decreases bad cholesterol Ex: olive oil, avocado, soybeans, red meats, fish Cholesterol= waxy substance made by liver and in food to coat circulatory system and assist blood flow, too much=bad

Fats Triglycerides are most common 3 fatty acids attached to glycerol

Phospholipids Main component of cell membranes

Proteins Chains of amino acids C, H, O, N Monomer= amino acids Important for structure, enzymes, and all life processes

Protein Synthesis A protein is a chain of amino acids linked by peptide bonds Peptide bonds: Type of covalent bond Links the amino group of one amino acid with the carboxyl group of the next Forms through condensation reactions

Condensation Reactions (pg. 42)

Condensation Reactions (pg. 42)

Protein Shapes Fibrous Globular Polypeptide chains arranged as strands or sheets Globular Polypeptide chains folded into compact, rounded shapes

a primary structure one peptide group b secondary structure 1 2 b secondary structure 3 4 5 6 7 coil, helix sheet c tertiary structure barrel coiled coils p.43

alpha globin alpha globin heme beta globin beta globin p.44

Nucleic Acids Monomer= nucleotide Single- or double-stranded Sugar-phosphate backbone Adenine Cytosine

Nucleotide Structure Sugar At least one phosphate group Deoxyribose Ribose At least one phosphate group Nitrogen-containing base Single ring Double ring

Deoxyribonucleic Acid (DNA) Double-stranded to form a helix Four types of nucleotides Adenine Thymine Guanine Cytosine Stores genetic information

Ribonucleic Acid (RNA) Single-stranded Four types of nucleotides Adenine Uracil Guanine Cytosine Messenger molecule to direct protein synthesis

ATP – A Nucleotide Energy molecule in cells (transfers energy in cells)

Condensation Reactions Also called dehydration synthesis Form polymers from subunits (monomers) Enzymes remove “-OH” from one molecule, “-H” from another, and form bond between two molecules Discarded atoms can join to form water

Condensation

Hydrolysis A type of cleavage reaction Breaks polymers into smaller units (monomers) Enzymes split molecules into two or more parts An -OH group and an -H atom derived from water are attached at exposed sites

Hydrolysis