Chapter 2 The Chemistry of Life

Chemistry will help you learn Biology because organisms, 2-1 Nature of Matter Chemistry will help you learn Biology because organisms, Including yourself, are Chemical machines.

All matter is made up of atoms. An atom is the smallest unit of Matter that cannot be broken Down by chemical means.

Protons Neutrons Electrons All atoms are made up of 3 parts… Protons Neutrons Electrons

Protons are positive parts. Neutrons are neutral parts. Electrons are negative parts.

These are real atoms!

Usually there is an electron For every proton in an atom. This keeps them electrically Neutral. When the number of electrons Is different than the number of Protons, the atom is called An Ion.

If there are more protons then the atom will have a Positive charge. If there are more electrons, Then the atom will have a Negative charge.

An element is a substance made Of only one kind of atom, and It is therefore a pure substance. Elements are organized in the Periodic table and represented By a 1, 2, or 3 letter symbol. H, O, C, Fe, Na, UUQ

Atoms can join together with Other atoms to form stable Substances. A force that joins atoms is Called a chemical bond. A compound is a substance made Of the joined atoms of 2 or More different elements.

For example, water is a compound That is made up of hydrogen And oxygen atoms.

A covalent bond forms when 2 or More atoms share electrons To form a molecule.

Water is a molecule, so is Carbon dioxide and oxygen gas.

When you have an unequal Distribution of electrical charge, A hydrogen bond is formed.

Is an atom that has gained Or lost electrons, giving it a charge. If you remember, an ion Is an atom that has gained Or lost electrons, giving it a charge. When 2 ions come together, they Create an ionic bond. In an ionic bond, the electrons Are given up by one atom and Gained by the other atoms.

Water is nearly 70% or your body. So water is a major component 2-2 Water and Solutions Water is nearly 70% or your body. So water is a major component Of cells.

The hydrogen bonds between Water molecules cause cohesion Water bonds to itself And other substances. The hydrogen bonds between Water molecules cause cohesion Of liquid water. Cohesion is an attraction Between substances of the Same kind.

Water molecules are also Attracted to other substances, This is adhesion. Adhesion is the attraction between Different substances.

Many substances dissolve In water. When you dissolve something into Water, you make a solution. For example, when you put salt In water, it will dissolve and the Salt molecules evenly distribute Throughout the water.

LIKE DISSOLVES LIKE!! Polar molecules, like water, will Dissolve other polar molecules, Like salt. Nonpolar molecules, like oil, will Dissolve other nonpolar molecules, Like fat. LIKE DISSOLVES LIKE!!

An acid is a compound that when Dissolved in water, will make More hydrogen ions (H+) than Pure water. A base is a compound that when Dissolved in water, will make more Hydroxide ions (OH-) than Pure water.

Strength of an acid or base, The pH scale was invented. In order to measure the Strength of an acid or base, The pH scale was invented. Acids have a pH less than 7, Bases have a pH more than 7, And pure water is neutral at 7.

Things in your body that are not Made up of water are made 2-3 Chemistry of Cells Things in your body that are not Made up of water are made Made of organic compounds. Almost all organic compounds Contain hydrogen, oxygen and Carbon.

Carbohydrates are organic Compounds made of carbon, Hydrogen and oxygen atoms in A ratio of 1:2:1. Carbohydrates are a key Source of energy, and are Found in most foods.

Carbohydrates are single sugars Called monsaccharides. The building blocks of Carbohydrates are single sugars Called monsaccharides. C6H12O6

Energy stored in bonds between elements is released when bonds are broken. C6H12O6 + 6 O2        6 CO2 + 6 H2O + energy

There are 3 simple sugars, Glucose, galactose and fructose. They all have the same formula C6H12O6!!

A disaccharide forms when two monosaccharides are combined. For Example glucose + glucose = maltose (formed during the digestion of starches)

A polysaccharide is a chain of 3 or more monosaccharides (beaded necklace)

In animals-glycogen (animal starch) stored in liver and muscles Polysaccharides are a way excess sugars are stored in living things. For example: In plants-starch In animals-glycogen (animal starch) stored in liver and muscles

Lipids are organic molecules that Are nonpolar and thus not Soluble in water. They include fats, phosolipids, Steroids, and waxes. At room temp. fats are solids and oils are liquids.

Lipids have 4 functions… long term energy storage b. insulation c. protective cushion between organs d. biological membranes

All lipids are made with a glycerol And chains of fatty acids.

A protein is a chain or molecules Called amino acids linked Together. An amino acid is the building Block of proteins. Contain NITROGEN as well as carbon, oxygen, and hydrogen.

Proteins are essential for growth and repair of body (at the cell level). They make up most of the solid “stuff” within your body (ex. Muscle, skin, hair, organs, …)

Amino acids are the building block of proteins. There are only 20 that make up our whole body.

All of the cells in your body contain Nucleic acids. A nucleic acid is a long chain of Smaller molecules called nucleotides. A nucleotide has 3 parts: Sugar, a base and a phosphate

There are 2 types of nucleic Acids: DNA and RNA. DNA consists of 2 nucleic acids Spiraled around each other and RNA has only 1.

Another important biological ATP is a single nucleotide and Molecule is ATP. ATP is a single nucleotide and Is where your body Gets its energy from.

Energy is the ability to 2-4 Energy & Reactions Energy is the ability to Move or to produce heat.

Metabolism is the term used To describe all of the chemical Reactions that occur in An organism. Some reactions require energy To get started, that is called Activation energy.

Enzymes are substances that Increase the speed of Chemical reaction in the body. Most enzymes are proteins. Enzymes are catalysts, these Are things that speed up Any chemical reaction.

If you didn’t have any enzymes In your body, it would take 6 months to digest just 1 candy bar!! Some enzymes can speed up Reactions up to 10 million times.

All enzymes are specific to a reaction. pepsin- digests proteins catalase- breaks hydrogen peroxide (2H2O2) into 2H2O + O2

A substance on which an enzyme Acts is called a substrate. Enzymes have active sites that Allow other molecules to fit. All enzymes are affected by changes in pH, temperature, and concentration.

THE END