Discussion Question #4 Besides candy and sweets, what sort of foods contain sugar? What is the purpose of an enzyme?

4 Macromolecules of Life Chapter 6 4 Macromolecules of Life

What are cells made of? The 4 major elements that make up the majority of our bodies and cells in general are: Carbon, Hydrogen, Oxygen, Nitrogen These 4 elements combine in different ways to make organic compounds. The 4 classes of organic compounds are: Carbohydrates Lipids Proteins Nucleic Acids Without these compounds the mighty cell would not function, thus we would not have life. How is an organic molecule different from an inorganic molecule? Organic molecules contain carbon atoms. A monomer is a small molecule made of different atoms. When several monomers combine into a bigger molecule they create a polymer.

Building and Breaking Polymers Building polymer chains: When a monomer is added to a polymer chain a water molecule is released, this is called a dehydration reaction. Breaking polymer chains: When a polymer chain is broken into smaller monomers a water molecule is added, this is called a hydrolysis reaction. Removing water builds a polymer, adding water breaks it down.

Condensed Structural Formulas Count how many bonds each C atom has: ____ Count how many bonds each H atom has: ___ Count how many bonds each O atom has: ___ Often, a condensed structural formula for sugars is used, where angles in the hexagons represent carbon atoms and obvious bonds are understood to be present and not drawn. Can you verify that all atoms and bonds are accounted for in sucrose? This hydrogen has ___ bond(s) to an ________atom . Oxygen has ___ bond(s). This oxygen is bonded to a hydrogen and a ______ atom. Carbon has ____bond(s). This carbon is bonded to a _______atom, an ________atom and two __________atoms.

Carbohydrates Building Blocks: simple sugars (1:2:1 ratio, ex: C6H12O6) Function: Main energy source, structural support for plants, certain exoskeletons 3 types of carbohydrates Monosaccharides: made of 1 simple sugar Ex: glucose(major energy source in cells), fructose Disaccharides: 2 simple sugars or 2 monosaccharides bonded together. Ex: sucrose, lactose(milk), maltose Polysaccharides: 3 or more simple sugars bonded together Ex: starch(plants), cellulose(plants), glycogen (meat/insulin) Your body has enzymes to break down polysaccharides into a more usable sugar (saliva enzymes). Sugars that do not get broken down and used as energy get stored as fat

Lipids Building Blocks: glycerol and fatty acids Types of lipids: fats, phospholipids, steroids Functions: Fats: Long term energy storage, breaking bonds releases energy Phospholipids: make up the lipid bilayer of cell membranes: hydrophobic vs hydrophilic = water-hating vs water-loving Steroids: cholesterol (4 ring structures) helps regulate hormones 2 types of fats: Saturated: fully saturated with hydrogen, straight molecule, no double bonds (bad fat) Unsaturated: kinked due to double bonds

Saturated vs Unsaturated Fat Hydrophilic vs Hydrophobic

Proteins Building Blocks: amino acids (20 total) Amino acids combine to make polypeptides, polypeptides combine to make a protein Functions: Key for building muscle, and hair. Enzyme proteins: catalyze (speed up) chemical reactions in the body. Collagen proteins: structural support and found in skin, ligaments, tendons, bones. Hemoglobin proteins: carry oxygen from your lungs to the rest of your body. Antibody proteins: used in immune system. Denaturation: process of taking a protein that looks like a ball of yarn and untangling it to look like a string.

Some of the 20 essential amino acids necessary for life:

Nucleic Acids Building Blocks: Nucleotides 2 types of nucleic acids 3 parts of a nucleotide Sugar Nitrogen base Phosphate group 2 types of nucleic acids DNA: double stranded helix RNA: single stranded molecule Functions: store genetic material, manufactures proteins, can act as an enzyme ATP: an important nucleotide that is the “energy currency of the cell”

Enzymes Enzymes lower activation energy For a chemical reaction to occur a certain amount of “start up” energy is required to get it going. This is called activation energy, because it activates the reaction. Something that speeds up a reaction by reducing the activation energy is called a catalyst. campfire The main catalyst for reactions in living things are enzymes. Enzymes lower activation energy

Factors Affecting Enzymes pH Depends on enzyme; maltase functions best in a pH of 7; pepsin, found in the stomach at a pH of1.5-2.2; trypsin, in the small intestine, pH 7.9-9.0 Temperature Most function best at body temperature 370 C Lower temp activity of enzyme decreases As temp is raised activity increases until a maximum is reached at about 400 C; beyond this point enzyme becomes distorted and enzyme deactivation occurs Relative amounts of enzyme and substrate Amt of enzyme increased, while substrate remains constant; rate of reaction is increased to a point; after that rate remains constant Amt of substrate is increased, while concentration of enzymes remains the same; rate of reaction will increase and will continue up to the point where every available enzyme molecule is actively involved in the reaction

How do enzymes work? The substrate binds to the enzyme at the active site (special groove where the enzyme attaches) The enzyme lowers the activation energy which speeds up the reaction The substrate’s bonds break, which releases energy, and the new molecules are released

Enzyme Activity Graph Which enzyme works best at lower temperatures?_____ At what temp do both enzymes have the same activity?_____ Which enzyme would most likely be found in the body?_____