The Chemical Basis of the Body CHEMISTRY The Chemical Basis of the Body

MATTER anything that has mass and occupies space solid - liquid – gas Made up of chemical building blocks called ELEMENTS “you take up space, you have a mass, YOU MATTER!”

Elements The building blocks of matter

Atoms the smallest unit of Matter That can enter into chemical reactions two basic parts Nucleus Electrons

Nucleus Protons (+ charge) Neutrons (uncharged) # of protons = elements Atomic Number Neutrons (uncharged) charge of the Nucleus is + Electrons - negatively charged particles-orbit around the nucleus # of electrons always equals the # of protons in an atom

Other Elements

Ions When an element loses or gains an electron Potassium( K+) and Sodium(Na+) are important ions in the body Also called Cations and Anions

Most Abundant Elements There are 26 elements in the body Most abundant are CHON 96% of total body mass O2 is most abundant at 65%

Molecules The combination of two or more elements held together by a chemical reaction. May be atoms of the same element H2, O2, N2, etc. May be atoms of different elements NaCl, HCl etc.

Compounds A substance that can be broken down into two or more elements by chemical means. Molecules of a compound always contain atoms of two or more different elements. ***All compounds are molecules but not all molecules are compounds***

Compounds Combination of two or more atoms

Cations Cations Cations are formed when an atom loses an electron or electrons to another atom creating an overall positive charge. Example: Na+

Anions Anions An anion is formed when an atom gains an electron or electrons from another atom creating an overall negative charge. Example: Cl-

Chemical Bonding Chemical bonds are formed between atoms when electrons in the outermost orbital are gained, lost, or shared

Ionic Bonding One loses and one gains an electron held together by the attraction strongest type of chemical bonding

Covalent Bonding the sharing of electron pairs single covalent bond = share one pair of electrons double covalent bond = share two pairs of electrons triple covalent bonds = share three pairs of electrons

Hydrogen Bonds covalently bond with H and another element very weak bond (5%) Often serves as a bridge between molecules. Easily broken

Polar Bond Unequal sharing of electrons Property of water that aids in movement of water

pH A scale used to describe the degree of acidity or alkalinity (basicity) of a solution. Actually represents the number of H+ ions or OH- ions in solution. H+ is acidic OH- is basic

pH scale ranging from 0-14. Based on the number of H+ ions Acid-below 7 Base-above 7 A neutral substance has a pH of 7.0. The Ph of blood: (alkaline) ranging from 7.35 to 7.45.

Water Universal solvent transports substances Lubricant Absorbs and releases heat slowly Aids in chemical reactions Most important inorganic compound

Solute, solvent, solution L/G in which some other solute has been dissolved Solute Atom or molecule that has been dissolved

Solution The aqueous combination of a solvent and solute

Inorganic compounds Lack carbon Vital for homeostasis Many are ionically bonded Water Acids Bases Salts

Organic Compounds Organic Compounds Contain carbon, hydrogen and Oxygen Held together by covalent bonds

Carbohydrates Formula is C6H12O6. structural units in DNA and cell membrane MAJOR ENERGY SOURCE for the body. ONLY energy source for brain and nerve cells. Blood sugar is known as glucose

Lipids (FATS) insoluble in water Most common are triglycerides composed of glycerol and fatty acids. second source of energy Protects body organs Provides insulation and warmth Absorbs fat soluble vitamins Forms sex hormones and steroids--see handout

Proteins building blocks called Amino Acids (20) structure of body tissues Form enzymes which are catalysts antibodies Regulate Osmotic pressure in the blood Function as storage molecules

Nucleic Acids DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Contain the atoms C,H,O,N AND P DNA stores the genetic code on chromosome DNA and RNA assist with protein synthesis A-T & C-G

Structure of RNA RNA is formed by a single strand of nucleotides RNA can leave the nucleus Helps make proteins Transfers amino acids for proteins

Adenosine-TriPhosphate (ATP) in all living systems Drives all chemical reactions Occurs through a process called cellular respiration ATP + H20 <----> ADP + P + ENERGY

Electrolytes Ions in the fluids of the body Essential to many processes in the body Can be lost through fluid loss

The End! ATP is found in the Mitochondria