Chapter 2

Basic Chemistry

Define, in your own words: Atom Element Proton Neutron Electron

All matter is made up of substances called elements. Only 92 naturally occurring elements Body is composed of only a few elements Carbon Nitrogen Oxygen Hydrogen Phosphorous Calcium Atoms – smallest unit of an element Made up of: Protons – + charge, nucleus of atom Neutrons – 0 charge, nucleus of atom Electrons – ( - ) charge, orbit around nucleus

Same element differs in the number of neutrons in the nucleus and weight. Carbon has 2 common isotopes Carbon-13 and Carbon-14

As isotopes break down they release energy in the form of rays and subatomic particles Carbon-14 is a common Radioactive isotope Unstable and breaks down over time ronmental/earth/geology/carbon- 14.htm

Molecule – 2 or more of the same atoms bonded together to form a chemical unit Compound – 2 or more different atoms bonded together to form a chemical unit. Types of Bonds: Ionic – created by an electrical attraction Covalent – sharing of electrons

Polar Covalent – electrons spend more time with the more electronegative element Non-polar Covalent – equally shared electrons Chemical Bonds

Elements in Living Things Coloring Handout

Study Questions pg 39 # 1-4

Water, Acids and Bases

What is the difference between ionic and covalent bonds? What elements make up the human body?

Organic Molecules – contain carbon Carbohydrates, proteins, lipids Inorganic Molecules – do not contain carbon Most important molecule is WATER

Polarity and Hydrogen bonding gives water all of it’s unique and beneficial properties. Solvent for polar molecules Cohesive – water molecules stick together Adhesive – water molecules stick to other surfaces High Specific Heat Capacity/Heat of vaporization Video

Acids – substance that separates in water Bases – takes up hydrogen ions or releases hydroxide ions pH scale – ranges from 0-14, indicates the acidity and basicity of solutions Acids and bases pH scale

Depending on what you’ve eaten recently, the pH of your urine can vary from 5 to 8. Which is more acidic – urine at pH 5 of pH 8

Study Guide Questions pg 39 # 6-7

Molecules of Life

Name the 4 important molecules of life Macromolecules

^ Dehydration Synthesis -remove water, make bigger molecules < Hydrolysis – add water, break down molecules

Monosaccharide – one carbon ring. Ex: Glucose, Fructose Dissaccharide – two carbon rings. Ex: sucrose Polysaccharide – three or more carbon rings. Ex: starch, cellulose

 Made up of C, H, O in a 1:2:1 ratio  Glucose – used as an immediate source of energy  Maltose is 2 glucose molecules, found in alcoholic beverages  Sucrose – glucose & fructose together, this is table sugar  Lactose – glucose and galactose, this is found in milk

 Means many sugars, LONG chains of sugar molecules  Starch – energy storage in plants  Glycogen – energy storage in animals  Cellulose – what cell walls are made up of  We cannot digest this, this helps to scrape the walls of our intestines

Saturated Fats - have only single covalent bonds, solid at room temperature. Ex: Butter (usually of animal origin) Unsaturated Fats – have double/triple bonds, liquid at room temperature. Ex: Oils (usually of plant origin)

Made of a glycerol molecule and a triglyceride, or three fatty acids. Can be emulsified – mixed with water, molecules position themselves around a droplet so that their nonpolar ends stick out and the droplet disperse in water Phospholipids – contain phosphate group, important for cell membranes Steroids – different structure than fats, back bone of 4 carbon rings, with differing side chains cholesterol is an example of a steroid

Macromolecules made up of 20 different Amino Acids Amino acids are arranged as follows Central carbon atom An amino group An R Group

 Composed of amino acids  When two amino acids join, called a dipeptide  Polypeptide contains 3 or more amino acids  Primary Structure  Sequence of Amino acids in a polypeptide  Secondary Structure  Coiling or folding of the protein  Tertiary Structure  Hydrogen, ionic, covalent bonding all occur in polypeptides  Quaternary Structure  Protein that has more than 1 polypeptide, arrangement of individual polypeptides  When proteins are exposed to extreme heat and pH they denature, and this is irreversible

 The sequence of amino acids found in a protein is that protein’s __________ structure a. primaryb. secondary c. tertiaryd. quaternary

 Protein catalysts  Enable particular metabolic reaction to occur at the body’s normal temperature  Energy activation – energy needed to start a reaction  Substrates – reactants in an enzymatic reaction  Enzymes are very specific this is caused by the shape and chemical composition of it’s active site.

Two Classes: RNA – ribonucleic acid, bases are AUGC DNA – deoxyribonucleic acid, bases are ATGC

 Adenosine plus 3 phosphate groups  PRIMARY ENERGY CARRIER IN CELLS  Cells require a constant supply  continually break down glucose  Some uses:  Synthesizing macromolecules  Muscle contraction  Conduction of nerve signals

Macromolecules Worksheet #2 Study Questions # 9,10,11,12,15,18