Chemistry of Life

Matter Matter-anything that takes up space and has mass All matter is made up of atoms Atoms may also join together to make up everything on our planet

Physical properties of matter Can be observed and measured without changing the identity of the matter Examples: mass, volume, color, odor, shape, texture, taste, melting, boiling

Chemical properties of matter Its ability to change into another substance It is permanently altered Examples- burning anything, rusty nail

Phases or states of matter Solid, liquid or gas Determined by temperature High temperature has more energy, atoms move faster and are farther apart Low temperature has less energy, atoms move slower and are closer together

Atoms, elements Atoms are the basic unit of matter, the smallest particle possible that is still that substance Atoms are too small to see with the eye or light microscopes

Atom structure: made of 3 particles Proton Positive Found in nucleus Neutron Neutral Electron Negative Orbits the nucleus

Electrons are found in energy levels 1st level holds 2 electrons 2nd level holds 8 electrons 3rd level holds 8 electrons 4th level holds 8 electrons Some levels have sublevels but it is considered full with 8 electrons

Atomic number Tells the number of protons in an atom Atoms of one element will always have the same number of protons

Atomic mass Tells the number of protons and neutrons together Electrons are not counted because they are too small To figure out the number of neutrons you subtract atomic number (protons) from mass number

Example: Oxygen has an atomic # of 8 an atomic mass of 16 Therefore oxygen has 8 protons 16-8 = 8 neutrons If atom has no charge then the pluses and minus are equal so oxygen has 8 electrons

Elements All one type of atom 92 occur naturally on the earth A symbol is used for each one (usually 1 or 2 letters) Names are usually from Latin or Greek O = oxygen C = carbon Ag = silver N = nitrogen He = Helium Au = gold

Periodic table of the elements A chart that arranges the atoms by size, chemical properties and the # of electrons

Compounds, bonds, reactions Compounds-2 or more elements combine to form a new substance. It is written with a formula Formulas tell the kind and number of atoms present Examples H2 O H2 SO4 C6 H12 O6

Bonds are how atoms join together. Chemical Bond Bonds are how atoms join together. Bonding occurs at the outside level of electrons. Atoms will join with other atoms in order to have a full outside level.

Ionic bond-a transfer of electrons from one atom to another The atoms are charged and are called ions It is a weak bond and broken easily Example: table salt One atom of sodium joins to one atom of chlorine sodium has 1 e- on outside, it transfers it to the chlorine Na Cl

Covalent bond-two atoms share their electrons Covalent bond-two atoms share their electrons. This is a very strong bond. Example-water oxygen has 6 e- hydrogen has 1 e- By sharing their electrons each atom fills up their outside level

Reaction-when substances combine to form new substances Reactants-what is present before the change occurs Products-what is present after the change reactants  products Na + Cl  NaCl

Water, solutions 75% of the earth’s surface is water It is the most abundant compound in living things Properties of water: Water is a polar molecule. This means it has a charge on it. This allows water to dissolve other substances well.

solution-one substance is dissolved in another substance solvent-substance that does the dissolving water is the best solvent solute-the thing that is dissolved

Cohesion-water’s ability to cling to itself Adhesion-water’s ability to cling to other substances These create capillarity and surface tension

Hydrophilic-applies to things that like water Hydrophobic-applies to things that hate water

Acids, bases, pH scale Acid-gives off H+, tastes sour, conducts electricity, dissolves metals examples: HCl, HNO3, H2SO4 the hydrogen is usually written first Base: gives off OH-, tastes bitter, feels slippery examples: NaOH, KOH the hydroxide (OH) is usually written last

pH scale measures the concentration of H+ it goes from 0 to 14 each number is 10 times the concentration

pH has an effect on living things H+ is very reactive and is part of many compounds in the body. The pH levels in the body must be kept at certain levels. This is done with buffers that maintain homeostasis

Neutralization combining an acid and a base of equal strength forms salt water example acid + base --> salt + water HCl + NaOH --> NaCl + H2O

Organic molecules Organic compounds contain carbon carbon forms 4 covalent bonds-it is very stable and used to make many important molecules in the body.

Polymerization-process of making large molecules by joining small ones monomer-small molecules polymer-large molecule made of a chain of smaller molecules

#1- Carbohydrates Carbohydrates-commonly known as sugars and starches atoms used: C, H, O monomer (monosaccharide): single sugar Polymer (polysaccharide):huge chains of sugars

plants: store long chains of sugar as either starch or cellulose animals: store long chains of sugar called glycogen in their liver

The role of carbohydrates: sugars are the main source of energy, they are stored until needed in long polymers

#2-Lipids Lipids are fats, oils, waxes atoms used: C, H, O monomer-fatty acid and glycerol role in the body: energy, cushion body tissues, insulate

Unsaturated fat-has less hydrogen (means there are double bonds on the carbon) Saturated fat-full of hydrogen (no double bonds)

#3-proteins and enzymes Role in the body-Proteins are used to build body tissues (blood, skin, muscle, nerves). They are also hormones, enzymes, pigments, antibodies atoms used: C, H, O, N monomer: amino acids

There are 20 different amino acids There are 20 different amino acids. They are linked together in different chains and orders to make all the thousands of proteins found in your cells.

Enzymes are proteins that act as catalysts catalysts are things that make reactions go faster the thing they work on to join or break apart is called the substrate

Lock and key theory: an enzyme has an active site that fits the molecule exactly. It does not fit any other substance. The enzyme can only do one job but it can do that job as fast as 1000 times per second.

#4-nucleic acids Nucleic acids: commonly known as DNA and RNA atoms used: C, H, O, N, P Monomer: nucleotide ( a combination of a sugar, a phosphate and a base) These are stacked on top of each other and across from each other to form a molecule that is 3 billion units long role: contains the genetic information for making the organism

Structure: DNA is built like a ladder that is twisted. (Called a double helix)

DNA bases: A = adenine T = thymine C = cytosine G = guanine S -A-T- S P P S S -G-C- P P S -C-G- S P P S S -T-A-

RNA bases A = adenine U = uracil C = cytosine G = guanine S -A P S -U

Differences in DNA and RNA: different sugars used in each DNA has 2 sides, RNA has one DNA uses thymine, RNA uses uracil