Section 1 Chemistry of life

Atoms Everything in the universe is made of tiny particles called ATOMS Stars in the sky Air you breath Water you drink The paper in your notebook The atoms are so small that you cannot see them without microscopes. If you lined up 3 million atoms side by side they would only reach across the period at the end of this sentence.

100 Different Types of Elements Each type of atom is called an ELEMENT You have seen them in the Periodic Table of Elements in every Science Book at the back Scientists use one or two letter abbreviations to symbolize each element. The first letter is always capitalized The second letter is always lowercase

Common Elements & their symbols you need to know Hydrogen H Carbon C Nitrogen N Oxygen O Sodium Na Phosphorus P Sulfur S Chlorine Cl Potassium K Calcium Ca Iron Fe

Molecules Most of the substances you see are not made of only one type of atom. Atoms bind together to form larger particles called molecules Some molecules have only a few atoms for ex: the air you breath has two molecules of oxygen ex: water is made of one oxygen & two hydrogen

Abbreviations & Numbers Scientists use abbreviations and numbers to symbolize molecules Ex; water is H 2 0 The small 2 written below the line after the H means that water has two hydrogen atoms There is not a number after the O, so that means there is only one oxygen atom

Glucose A sugar that is the major source of energy in plants and animals C 6 H 12 O 6 It has six carbon atoms It has twelve hydrogen atoms It has six oxygen atoms GET IT?

Quantity If you are dealing with more than one of the same kind of molecule, you write the number of molecules before the symbol of the molecule 60 2 What do you think this means? It means we have six molecules of oxygen

Water Your body is 70 percent water!!! It transports substances throughout your body It is VERY important for chemical reactions to take place in your body

Water Molecule The atoms in a water molecule do not form a straight line Instead, they form a triangle Water serves as a solvent for many other molecules. Salts and sugars can dissolve easily in water. Oils do not dissolve easily in water.

Molecules of Life Living things are made up of many types of chemicals There are four groups that are unique to all living things Carbohydrates Lipids Proteins Nucleic acids CARBON ATOMS FROM THE BACKBONE OF ALL FOUR! THEREFORE WE CALL THEM ORGANIC MOLECULES

Carbohydrates Sugars Starches Cellulose The store energy

Lipids Molecules that make up fats and oils Plants & Animals use them as fat reserves Layers of fat could insulate an animal from extremely cold temperatures They are in your nerve cells, hormones & cell membranes Lipids do not dissolve in water

Heard of good fats & bad fats? Good fats are called polyunsauturated and are liquid at room temperature. You can find them in fruits and vegetables. Bad fats, are called saturated fats, and they cause heart disease. They are solid at room temperature and found in meats and dairy products

Saturated fat in meats- bad fats

Unsaturated fats- Good fats

Proteins Hold your skin together Give your bones strength Help you fight diseases Are an excellent source of energy Most importantly- they control chemical reactions in your body Proteins are composed of long strings of units called Amino Acids. There are 20 types of amino acids. Think of amino acids as letters and proteins as words

…proteins continued Heat and chemicals, such as acids, can disrupt the weak bonds between amino acids The protein my partially unravel It can never again regain it’s original shape This happens with a fried egg. The egg white (which is made of protein) turns from a clear liquid to a white solid. No matter how much you cool the egg it will never go back

It can never regain the shape

Enzymes Enzymes are some of the most important proteins in all living things They break down food Repair tissue Manufacture chemicals Without enzymes, all chemical activity would stop in your body

Enzymes continued… All chemical reactions need energy to get going. A tsp of sugar will eventually break down into carbon dioxide and water but could take millions of years Your body cannot wait that long to break down sugars for your energy Instead they use ENZYMES

What do enzymes do? Enzymes are proteins that speed up reactions by reducing the amount of energy needed for these reactions to take place Each enzyme can trigger only one type of reaction. Much like one key only fits into a certain lock. One type of molecule can bind to one type of enzyme