01 Chapter 2 Lesson 1 Basic Chemistry

Matter anything that has mass and occupies space Examples: ? ?

Elements all of the atoms w/ the same atomic number Living organisms require about 20 w/ C, H, O, and N making up more than 95% of the human body! composed of atoms: the smallest stable unit of matter chemical symbols (oral review)

Atomic Structure Atom Diagram WKST A Concept Map Atomic Structure Atom Diagram WKST A

Isotopes forms of an element whose atoms contains the same # of protons (p+) but different numbers of neutrons ( n ) are distinguished by mass # : total # of p+ and n in the nucleus

Isotopes cont’ All isotopes of a particular element have the same number of e- and react chemically the same. Therefore, any of the isotopes of oxygen can play the same role in an organism’s metabolic reactions.

Isotopes cont’ Unstable isotopes  aka: radioactive Atomic fragments/energy aka: atomic radiations The three forms of atomic radiations are alpha (α) beta (β) & gamma (γ) which is the most penetrating.

Isotopes cont’ Half-life: time required for isotope to lose ½ of its radioactivity Half-life of I-131 8.1 days P-32 14.3 days Co-60 5.26 years Ra-226 1620 years

Isotopes cont’ Uses: inflammatory disease Radioactive substances can by introduced into and organism and traced as it enters into metabolic activities Uses: I-131 thyroid Tl-201 heart conditions Ga-67 certain cancers & inflammatory disease Co-60 cancer

Atomic Weight the average mass of an element’s atoms Carbon 12.01 Hydrogen 1.01 Oxygen 16.00 Nitrogen 14.01

Electron Shells The charge on atoms is neutral! Chemical behavior of an atom results from the number of e- in the outer shell. An atom with full outer shell of e- : stable, inert, unreactive An atom with an incomplete outer shell tends to react w/ other atoms unstable, reactive

Bonding of Atoms Chemical bond: connection between atoms after a reaction produces molecules: chemical structures that contain more than one atom bonded together by shared e- or compounds: any chemical substance made up of atoms of 2+ elements regardless of the type of bond joining them

Bonding of Atoms cont’ Electrically charged atoms and molecules are: ions Cations = ion w/ positive charge Anion = ion w/ negative charge Most common in body fluids: Na + Cl - K + HCO3 - Mg ++ HPO4 3- Ca ++ SO4 2-

Types of Bonds IONIC :molecular bond created by attraction btw. ions w/ opposite charges COVALENT :a chemical bond btw. atoms that involves e- sharing HYDROGEN :weak interaction btw. H atom on one molecule and negatively charged portion of another molecule

WKST D: Ionic Bonds WKST C: Covalent Bonds

Chemical Reactions bonds form between atoms or existing bonds break btw. atoms Reactants GO INTO a chemical reaction. Products ARE PRODUCED. [come out of] described using chemical shorthand or chemical notation ex. water H2O glucose C6H12O6 table salt NaCl oxygen O

WKST H: Chemical Reactions

Chemical Reactions cont’ Decomposition reaction involving the addition of a H2O molecule: hydrolysis Cells can harness energy to power essential functions from the decomposition of complex molecules. This process is catabolism

Chemical Reactions cont’ A reaction that is opposite of hydrolysis is dehydration synthesis aka: condensation Catabolism supports the process of anabolism!

Chemical Reactions cont’ Acid-Base reactions are examples of exchange reactions in the body. Reversible reactions are 2 reactions occurring at the same time If balanced equilibrium

Enzymes Activation energy is the amount of energy required to start a reaction. Enzyme aka: catalyst: compounds that accelerate chemical reactions w/o being permanently changed in the reaction Function: lower activation energy which in turn speeds up chemical reactions

Enzymes cont’ If energy released is greater than activation energy: exergonic If more energy is required to begin the reaction than is released: endergonic Enzymatic binding depends on shape of moleculed.

Figure 2-19 WKST R: Enzymes

Water and Physiological Systems single most important constituent of the body accounts for nearly 2/3 of body weight Properties Essential reactant heat capacity: ability to absorb and retain heat Excellent solvent

Acids, Bases, and pH Acid: compound dissociates in solution releasing H+ ; pH 7 & excess of H+ HCl  H+ + Cl Base: compound whose dissociation releases OH- or removes H+ from solution OH- ions react quickly w/ H+ to form H2O NaOH  Na+ + OH-

Acids, Bases, and pH cont’ Salts: ionic compound consisting of any cation except H+ and any anion except OH- Salts are examples of electrolytes! Alterations in concentration can disturb almost every vital function!

Acids, Bases, and pH cont’ pH: expressed in moles/ L; solutions are acidic if below 7; basic if above 7 and neutral if 7 The difference in concentration per whole number on the scale is tenfold! A solution with a pH of 6 has 10X the hydrogen ion concentration of a solution with a pH of 7

That should blow the cobwebs out of your brain!!

Coming Soon: to an Anatomy class near you Biochemistry !