Bio 130 Module 1.3 Basic Chemistry PDF

Basic Chemistry Why is chemistry Important to understand biology? Challenge Statement Our entire body is made up of protons, electrons, & neutrons Strongly Agree Not Disagree Strongly Agree Sure Disagree What are Elements Elements are the building blocks of all M...

Basic Chemistry Why is chemistry Important to understand biology? Challenge Statement Our entire body is made up of protons, electrons, & neutrons Strongly Agree Not Disagree Strongly Agree Sure Disagree What are Elements Elements are the building blocks of all Matter Anatomy of an Atom: Made up of subatomic particles:  Protons (+)  Electrons (-)  Neutrons (no charge) electron proton neutron HELIUM  Atoms Contains all properties of element Mass number= protons + neutrons  Electrons =very little mass Atomic number= # of protons Usually #protons=#electrons  Reading the Periodic Table Column= number electrons in outer shell Row = number of shells of electrons Understanding Valance e- Chemical Bonds Atoms try to fill vacancies in outer shell to achieve greater stability Outer shells are filled by:  Sharing electrons  Donating electrons  Accepting electrons Most outer shells hold 8 electrons  Octet rule Ions & Ionic bonds Atoms with uneven number of electrons and protons  Cation=positive charge=lost electron  Anion=negative charge=gained electron Electron Transfer  Na Donates e-  Cl Accepts e-  Octet rule satisfied Ionic Bond  Very strong Covalent Bonds Covalent Bond  Sharing of electrons  Strongest & most common in living organisms  Do not disassociate in water Unlike ionic bonds Polar Nonpolar Polar and Nonpolar Covalent Bonds Hydrogen Bonds Weak bond between polar covalent bound molecules containing hydrogen Positive charge of Hydrogen atom attracted to negative charge of molecule Gives water many life assisting properties Van Der Waals Interactions Weak bond between polar covalent bound molecules Caused by partial charge due to movement of electrons Isotopes & Carbon Dating Atoms of element with different # of neutrons are Isotopes  Carbon12 VS Carbon14 Radioactive Isotopes decay over time neutrons decay into protons Every 5,730 years half of Carbon14 will decay to Nitrogen14 Carbon dating compare concentration of C14 in remains to C14 in atmosphere  Anatomy of an Atom: Changing the number of subatomic particles:  Protons (+) = New Element  Electrons (-) = Ion  Neutrons (no charge) = Isotope electron proton neutron All about pH Water constantly splits in H+ and OH- and reforms back into water pH is the Measure of Hydrogen ion concentration (H+)  7=neutral (equal H+ and OH-)  7=basic (more OH-) Log Scale  1unit=10x change Calculating H+ concentration from pH Log Scale  1 unit is 10x change pH is the negative logarithm of H+ ion concentration pH=-log10(H+)  All about pH Human body pH 7.2-7.6 Buffers keep stable CO2 is vital to our buffer system  Carbonic Acid-Bicarbonate Buffer System When blood pH rises, carbonic acid dissociates to form bicarbonate and H+ H2CO3 -----> HCO3- + H+ When blood pH drops, bicarbonate binds H+ to form carbonic acid HCO3- + H+ -----> H2CO3