1Biology: Human Anatomy and PhysiologyChapter 2: The Chemical Level of Organization1.Identify, by name and symbol, the principal chemical elements of the human body.A.chemical element●This is a substance that cannot be split into a simpler substance●Ex. Oxygen,carbon,hydrate,nitrogen.B.chemical symbol●please help to identify the major elements.they are made up of one ortwo lettersto identify the element.●Ex. oxygen (O), Calcium (Ca), Sodium (Na)C.major elements●There are only four major elements. These constitute for 96% of the bodymass.1.Oxygen2.Carbon3.Hydrogen4.NitrogenD.lesser elements●Include eight other elements that contribute to 3.6% of the body mass.1.Calcium:●Hardness of bones and teeth, Blood clotting,release ofhormones,contraction of muscle.2.Phosphorus:●Nucleic acids,ATP,bone in tooth structure3.Potassium:●Positively charged particle in the intracellular fluid,neededfor action potential.4.Sulphur:●vitamins and proteins5.Sodium:●Found in the extracellular fluid,needed for maintainingwater balance,and generating action potentials.6.Chloride:●negatively charged particle found in the extracellular fluid,needed for maintaining water b balance.7.Magnesium:●needed for the action of enzymes.8.Iron:
2●part of hemoglobin.E.trace elements●These are an additional 14 elements the only account for 0.4% of the bodymass.●Such as iodine2.Describe the basic structure of an atom, ion, molecule, compound and free radicle.A.atom●Unit of matter that makes up a chemical element; consists of a nucleus(containing positively charged protons and uncharged neutrons) andnegatively charged electrons that orbit the nucleus.●The dense central core of an atom is a nucleusNucleus:➔A spherical or oval organelle of a cell that contains the hereditaryfactors of the cell, called genes. A cluster of unmyelinated nervecell bodies in the central nervous system. The central part of anatom made up of protons and neutrons.1.Protons●Positively charged2.Neutrons●UnchargedB.subatomic particles●These are components that compose atoms●There are only three types of subatomic particles1.Protons2.Neutrons3.ElectronsElectrons:➔Negatively charged➔Move about in the large space surrounding the nucleus.a.electron shells:These are where the electrons move about1.First:never holds more than two electrons.2.Second:maximum of eight3.Third:can hold up to 18.C.atomic number●This is the number of protons in the nucleus●Each element will have a different atomic numbersD.mass number●This is thesumof its protons and neutrons
3●Ex.sodium has 11 protons and 12 neutrons,therefore it has a massnumber of 23.E.isotopes●these are atoms that have different numbers of neutrons therefore differentMass numbers.