Chemistry of Life

Small to large AtomsElementMoleculeMacromoleculeCellsTissuesOrgansOrganism

Small to large Atom: Smallest possible particle of an element Element: A pure substance that can not be broken down into other substances. Molecules: Two or more atoms held together by bonds Macromolecule: a very large molecule, Protein, carbohydrate, Lipid, Amino acids, Nucleic Acid Cells: Basic unit of living matter

Chemistry An atom contains; protons, neutrons, and electrons Atomic number: the number of protons found in the nucleus of an atom Periodic Table of Elements: An arrangement of elements based on their atomic number and mass Elements are also placed due to the number of electrons in the outer shell

Electrons and bonding The number of electrons in the outer shell determines how an element will react with another. Elements want to have “full” outer shells. To have a full outer shell an element will either share or transfer electrons Ionic Bonding: elements transfer electrons Covalent Bonding: elements share electrons

Water properties

Water All living things are dependent on water Cells are 70% to 95% water Water is the only compound found on earth in all 3 forms Water is one oxygen covalently bonded to two hydrogen's. Although this is a covalent bond the oxygen pulls the shared electrons closer to itself making it more negative and making the hydrogen more positive.

Water structure

Waters life-supporting properties Cohesion: The tendency of molecules of the same kind to stick to one another. Important in plants because as water evaporates it pulls itself upward in plants. Adhesion: Attraction that occurs between unlike molecules. Important because water sticks to the sides of the plant tubes and helps combat gravity.

Waters life-supporting properties Temperature moderation: Water has a very strong ability to resist change in temperature due to hydrogen bonding between molecules Water allows for temperature regulation of the world by staying cool in the summer and warm in the winter

Waters life-supporting properties Ice: the solid form of water that is lower density than the liquid form. As water freezes the molecules move further apart. Important because it allows animals to continue to live under frozen water instead of being frozen from the bottom up.

Waters life-supporting properties Water has a great ability to dissolve other substances. Water is the universal solvent Solvent: The substance that dissolves another substance Solute: The substance that is being dissolved Solution: A uniform mixture of two or more substances.

Acids, Bases, Buffers, Ph

Ph Scale Water sometimes breaks into ion’s of H+ and OH- Hydrogen ion(+) and Hydroxide ion(-) These ions are what determine whether something is an acid or base. The Ph scale is an exponential scale showing acids and bases.

Ph Scale Scale from 0 to 14 each step is 10x more than the next 0-6 is Acidic 7-8 is neutral 8-14 is Basic

LE 2-15 Acidic solution OH  HH HH HH HH HH HH HH HH HH HH HH HH HH Increasingly ACIDIC (Higher concentration of H  ) Neutral solution OH  HH HH Basic solution NEUTRAL  H        pH scale Lemon juice, gastric juice Grapefruit juice, soft drink Tomato juice Human urine Pure water Human blood Seawater Milk of magnesia Household ammonia Household bleach Oven cleaner Increasingly BASIC (Lower concentration of H  ) OH  HH HH Basic solution Milk of magnesia Household ammonia Household bleach Oven cleaner Increasingly BASIC (Lower concentration of H  )

Acids An acid is any substance that gives off H+ to the solution Ex: lemon juice, stomach acid Acidic solution OH  HH HH HH HH HH HH HH HH Increasingly ACIDIC (Higher concentration of H  ) pH scale

Bases A base is a compound that removes H+ from the solution by giving off OH- to bond with the H+ Ex: Soap, Bleach, Oven cleaner OH  HH HH Basic solution Milk of magnesia Household ammonia Household bleach Oven cleaner Increasingly BASIC (Lower concentration of H  )

Buffer Cells are very sensitive to H+ and OH- ions. Even a slight change in Ph will affect a cell. A buffer will accept H+ ions when they are too high and will donate H+ when they are too low. Blood is a great example of a buffer OH  HH HH HH HH HH Neutral solution NEUTRAL  H        Tomato juice Human urine Pure water Human blood Seawater

Chemistry of Life Carbon is the one element required for life Any Carbon based molecule is considered an organic molecule Each of the four macromolecules start with Carbon as the basis. CarbohydratesLipidsProteins Nucleic acids

Macromolecules Carbohydrate: Complex sugars made up of Carbon, Oxygen and Hydrogen Starch: a large chain of sugars Energy source of cells

Macromolecules Lipids: Water avoiding compound made up of Carbon and hydrogen chains Cholesterol: An essential lipid molecule needed for cell membranes. Lipids act as a barrier that contains the liquid parts of the cell. They also act as chemical messengers in the form of hormones.

Macromolecules Proteins: A large molecule made up of amino acids Amino acid: A small molecule that is made up of Carbon, Hydrogen, Nitrogen, and Oxygen. Proteins are large chains of amino acids that bond together and then fold to create useable cell parts. Proteins also make up enzymes which speed up chemical reactions.

Macromolecules Nucleic Acids: A large molecule made up of smaller molecules called nucleotides. Nucleotides: Small molecules made up of a sugar, a nitrogen base, and phosphate Nucleic acids are what our DNA or genetic material is made of With out nucleic acids our body would not have directions and could not function.

Proteins and Enzymes

Function of Proteins Made up of amino acids Responsible for most day to day functions of all cells Amino acids link together and form a long chain

Protein Shape The long Amino acid chain folds to make the protein useable A proteins shape is changed by its surroundings A protein that is outside of its normal environment will be denatured (misshapen)

Proteins to Enzymes A protein sometimes works as an enzyme An enzyme speeds up chemical reactions in our bodies An enzyme speeds up a reaction by making it easier. This is done by lowering the activation energy

Enzyme Enzyme: A protein that speeds up chemical reactions