BIOCHEMISTRY NOTES - UNIT 2- ATOMS - the basic unit of matter. Contains subatomic particles o (+ charge) o (no charge/neutral) o (- charge) Protons and neutrons have about the same mass. Electrons are much. Atoms have equal numbers of and. o Because these particles are opposite charges, the whole atom is. ELEMENTS AND ISOTOPES - a pure substance that consists of only one type of atom. Elements are represented by a 1 or 2 letter symbol. (ie: C = carbon) The number of in an element is that element s. o The atomic number of carbon is 6, therefore carbon has 6 protons and consequently 6 neutrons. Mass Number- the sum of the number of plus the number of. ISOTOPES - atoms of the same element that have different numbers of neutrons. o Isotopes are identified by their (ie: carbon- 12, carbon- 13, carbon- 14) The of the masses of an element s isotopes is called its. Isotopes have the same number of, so all isotopes of an element have the same.
RADIOACTIVE ISOTOPES Some isotopes are. This means that their nuclei are unstable and break down at a continuous rate over time. IONS - an atom that has gained or lost an electron, giving it a positive or negative charge. o - a positively charged ion o - a negatively charged ion CHEMICAL COMPOUNDS - formed by the chemical combination of two or more elements in definite proportions. o Compounds are typically written as a (ie: NaCl, CO2, etc.) This gives you the ratio elements in the compound. o The physical and chemical properties of a compound are usually very different from those of the elements form which it is formed. Chemical compounds are held together by, which are formed by the of each element. The electrons that are available to form bonds are called, and are on the. CHEMICAL BONDS - formed when one or more electrons are transferred from one atom to another. o Form between a and a. (between a and an )
NAMING IONIC COMPOUNDS The names of ionic compounds consist of the names of the that make up the compounds. o Names of are the as the elements of which they are composed. o Names of are names of elements. The difference is the name s. ( ) An ionic compound must have a. CLASS PRACTICE Na + F Mg + O K + I Ca + S YOU TRY IT! Li + O Ca + Cl K + Se Mg + Br NAMING IONIC COMPOUNDS Some cations (the metals) must show their charge. ex: FeO Fe2O3 CLASS PRACTICE TiN NiS Copper(III)oxide
YOU TRY IT! Iron(II)sulfide Gold(III)bromide CHEMICAL BONDS - results when electrons are shared between atoms. o The structure that results when atoms are joined together by covalent bonds is called a. o Covalent bonds usually form between. o Covalent bonds are the bonds between atoms. Covalent Bond- atoms share electrons, Covalent Bond- atoms share electrons. Covalent Bond- atoms share electrons. COVALENT COMPOUNDS Covalent compounds are named than ionic compounds. Unlike ionic compounds, compounds use. Prefixes tell how many of each element are in the molecule. If there is only atom of the first element, the name does not get a. The element furthest to the on the periodic table is named and ends in.
CLASS PRACTICE BF3 N2O4 Si I4 YOU TRY IT! P4S3 SeO2 As2O5 CHEMICAL BONDS - Hydrogen can form a special type of bonds with a couple of unique elements: A slight attraction that develops between charged regions of. o Not near as strong as ionic or covalent bonds, although they can hold molecules together, especially when the molecules are large. FORCES BETWEEN MOLECULES Forces- between atoms of two different molecules. o Ex: Forces- between atoms of the same molecule. o Ex: THE WATER MOLECULE The single most compound in most living things. Water as it freezes. Water is a molecule (equal # of protons and electrons).
Water is because there is an distribution of between the oxygen and hydrogen atoms. o The hydrogen ends of the molecule are slightly and the oxygen end is slightly. Because of the charges, polar molecules (such as water) can each other. The attraction between the hydrogen atom on one molecule and the oxygen atom on another molecule is an example of a. PROPERTIES OF WATER - an attraction between molecules of the same substance. (ex: water attracted to water) - an attraction between molecules of different substances. (ex: water attracted to glass). Ex: meniscus Water also has a high which allows it to form a skin- like surface. o Water has a high surface tension due to the strong forces between water molecules. o - compound that lowers surface tension. Example: any type of cleaner - the force that allows water to move against gravity. Example: water being absorbed up the roots in plants. SOLUTIONS AND SUSPENSIONS - composed of two or more elements or compounds that are physically mixed together, but not chemically combined. - all components are evenly distributed throughout the solution. o - the substance that is dissolved. o - the substance in which the solute dissolves. - mixture of water and non- dissolved materials.
ACIDS, BASES, AND PH - indicates the concentration of H+ ions in solution. This scale ranges from. - have a ph value. o Strong acids have a ph between 1-3. (ie: HCl) o Acids have a high concentration of, and a low concentration of OH- ions. - have a ph value. o Strong bases have a ph between 11-14. o Bases have a high concentration of, and a low concentration of H+ ions. - weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in ph. -. o has a neutral ph. CARBON COMPOUNDS - the study of all compounds that contain carbon. - made from thousand of smaller molecules. o - large compounds called polymers are built by joining smaller compounds (called monomers) together. There are four groups of organic compounds found in living things: o - made of monosaccharides. o - made of glycerol and fatty acid. o - made of nucleotides. o - made of amino acids.
CARBOHYDRATES - compounds made up of carbon, hydrogen, and oxygen atoms, usually in a 1:2:1 ratio. Living things use carbohydrates as their main source of. Plants and some animals also use carbohydrates for. (ie: cellulose- in plant walls) - single sugar molecules o ie: glucose, galactose, fructose - large macromolecules formed from monosaccharides. o ie: glycogen (animal starch), cellulose (plant starch) LIPIDS - made mostly from carbon and hydrogen atoms, which combine to form fatty acids and glycerol. The common categories of lipids includes,,, and. Lipids can be used to. If each carbon atom in a lipid s fatty acid chain is joined to another carbon atom by a single bond, the lipid is said to be, because it contains the maximum number of hydrogen atoms. If there is at least one C=C, they are said to be. NUCLEIC ACIDS - macromolecules containing hydrogen, oxygen, carbon, and phosphorous. Nucleic acids are polymers assembled from individual monomers known as.
Nucleotides consist of three parts: o o o Nucleic acids store and transmit hereditary or genetic information as and and help control the. PROTEINS - macromolecules that contain nitrogen, carbon, hydrogen, and oxygen. Proteins are made of molecules called which are held together by. Amino acids are compounds with an on one end and a on the other end. The instructions for arranging amino acids into many different proteins are stored in DNA. Each protein has a specific role. o Some proteins control the and o Some are used to. o Others into or out of the cells. o Some help. Proteins have 4 levels of organization: primary, secondary, tertiary, and quaternary.
CHEMICAL REACTIONS - a process that changes, or transforms one set of chemicals into another. o - the elements or compounds that enter into a chemical reaction. (on the left of the equation) o - the elements or compounds produced by a chemical reaction. (on the right of the equation) Chemical reactions always involve changes in the chemical bonds that join atoms in compounds. ENERGY IN REACTIONS Break Bonds = Form Bonds = Chemical reactions that energy often occur spontaneously. Chemical reactions that energy will not occur without a source of energy. ACTIVATION ENERGY - the energy that is needed to get a reaction started. ENDERGONIC EXERGONIC
ENZYMES - a substance that speeds up a chemical reaction. o Catalysts work by lowering a reaction s. - proteins that act as biological catalysts. o Enzymes chemical reactions that take place in cells. ENZYME ACTION Enzymes are very, generally catalyzing only 1 chemical reaction. - the reactants of enzyme- catalyzed reactions. (what the enzyme acts on) - place on the enzyme where the substrate binds. REGULATION OF ENZYME ACTIVTY Enzymes work best at certain values. Many enzymes are affected by changes in. Enzymes play essential roles in regulating chemical pathways, making materials that cells need, releasing energy, and transferring information.