Water & Biochemistry

Atom basic unit of matter –Subatomic particles: –Protons (P) Positive Nucleus –Neutrons (N) Neutral Nucleus –Electrons (E) Negative Outside the nucleus Example: Lithium Atom on/rad_sealed/matter/atom_structure.htm

Element Made up entirely of one type of atom More than 100 Represented by a one or two letter symbol –Carbon: C –Hydrogen: H –Nitrogen: N –Oxygen: O –Phosphorus: P –Sulfur: S “CHNOPS”

Reading the Periodic Table Background –Each element is identified by an abbreviation (H = hydrogen, Li = lithium, Na = sodium, K = potassium and so on –Elements are arranged in the periodic table in periods (horizontal rows) and groups (vertical columns). –Elements are arranged in the periodic table from left to right and top to bottom in order of increasing mass.

Reading the Periodic Table –Elements in each group have common structural and functional properties. For example, the elements in Group IA each have one electron in the outer shell of their atoms and are thus highly reactive. They tend to lose this electron in chemical reactions and to become ions with a single positive charge (e.g., H+, Na+, K+). Atoms in Group IIA each have two electrons in their outer orbit which are also easily given up to form ions.

Mass Number The sum of the number of neutrons and protons is called the mass number. The mass number for an element containing 3 protons and 3 neutrons such as Lithium is 6.

Atomic Number The number of protons in an atom is called the atomic number of the atom.

Chemical Symbol Elements are atoms that contain specific numbers of protons and electrons. The unique chemical nature of any element is defined by the number of electrons and protons. The chemical symbol for an atom containing 3 protons (atomic number of 3) is Li for Lithium.

Isotopes Atoms of the same element that differ in the number of neutrons. They have the same number of protons, but they have different mass numbers. Example: Lithium

Radioactive Isotopes Phosphorus 32 – used in agriculture for tracking a plant's uptake of fertilizer from the roots to the leaves Iodine 131 – can be used to test how well the thyroid gland is functioning Carbon 14 – its presence in organic materials is the basis of the radiocarbon dating method to date archaeological, geological, and hydrogeological samples

Molecule A group of atoms bonded together Example: Water H 2 O

Compound A molecule that contains atoms of more than one element ex. Glucose C 6 H 12 O 6

Chemical Bonds ionic bond – forms when two atoms are held together by the attraction between opposite charges. Example: NaCl (table salt)

Chemical Bonds covalent bond – results when two atoms share electrons in order to have a completed outer shell. Example: (H 2 ) Hydrogen gas

Formula Shows the composition of compounds Which elements and how many of each Ex: Glucose C 6 H 12 O 6 –6 – carbon –12 – hydrogen –6 – oxygen

Chemical Reaction Process that changes one set of chemicals into another set of chemicals 6CO 2 + 6H 2 O -> C 6 H 12 O 6 + 6O 2 Reactants -> Products

Energy in Reactions Chemical reactions that release energy often occur spontaneously Chemical reactions that absorb energy will not occur without a source of energy –Activation energy: energy that is needed to get a reaction started

Water single most abundant compound in living things –Polarity Slightly charged at each end due to uneven distribution of electrons –Hydrogen bonds: weak bonds that are responsible for many special properties of water Cohesion: attraction between molecules of the same substance Adhesion: attraction between molecules of different substances

Solutions and Suspensions Mixture: composed of 2 or more elements or compounds that are physically mixed together but not chemically combined Ex. Salt & pepper, Atmosphere Solution: mixture of 2 or more substances in which the molecules of the substances are evenly distributed Ex. Salt water Solute: substance that is dissolved (salt) Solvent: substance in which the solute dissolves (water) Suspensions: mixtures of water and nondissolved particles Ex. Blood

Acids, Bases, & pH Acid: compound that forms H+ ions in solution Base: compound that produces hydroxide ions (OH-) in solution pH scale: indicates the concentration of H+ ions in solution –ranges from 0-14 –below 7: acids –above 7: bases –7: neutral –The farther away from 7, the stronger the acid or base –Each step represents a factor of 10

pH Scale

Carbohydrates Compounds made up of carbon, hydrogen, and oxygen atoms Main source of energy for living things Examples: Glucose (Monosaccharide), Sucrose (Disaccharide), and Starch (Polysaccharide)

Glucose (Monosaccharide)

Sucrose (Disaccharide)

Starch (Polysaccharide)

Lipids Mainly made from carbon and hydrogen atoms Store energy Important to biological membranes Examples: fats and oils

Proteins Macromolecules that contain nitrogen, carbon, hydrogen, and oxygen Proteins are important structural components of living things. They make up sub-cellular membranes, skin, muscle fiber, hair, bones, and tendons. Immunoglobulins (also known as Antibodies) are proteins that attach to various foreign agents that invade the body and trigger bodily defense mechanisms. Channel proteins are found integrated in the plasma membrane and act as transports for signal ions and other products the cell needs to communicate and operate. Binding Proteins are important in functions such as transport of oxygen and carbon dioxide to and from the cell, such as in the protein, hemoglobin. Enzymes are specialized proteins that aide in or initiate (catalyze) biochemical reactions.

Structure of Proteins

Nucleic Acid Macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus Store and transmit genetic information Deoxyribonucleic Acid (DNA) is the molecule that contains genetic information for building proteins, which make up the traits of living things. Ribonucleic Acid (RNA) transfers the genetic information to the protein-making machinery within the cell. Nucleotides are the monomers of all nucleic acids. Certain nucleotide triphosphates, like Adenosine Triphosphate (ATP), are high-energy storage molecules used by organisms to provide energy for chemical reactions.

Structure of Nucleic Acids

Homework –Study material for Quiz #2 – Water & Biochemistry –Read Chps. 4 & 5 Pgs , –“Hoodia for Weight Loss” Pg. 89, –“Refugees from Global Warming” Pg. 107