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 ELEMENTS

Atoms The smallest unit of Matter Two basic parts Nucleus Electrons

Nucleus Protons (+ charge) Neutrons (uncharged) # of protons = element’s 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

Elements The building blocks of matter

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%

Other Elements

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

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

Molecules A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements. All compounds are molecules but not all molecules are compounds. Hydrogen (H2), oxygen (O2) and nitrogen (N2) are molecules. Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element. 

Formed when electrons are Gained, Lost, or Shared Chemical Bonding Formed when electrons are Gained, Lost, or Shared

Ionic Bonding One loses and one gains an electron Held together by their attraction Strongest type of chemical bonding Example: sodium (1) and chlorine (7)

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 Example: CO2, H20

Hydrogen Bonds Covalent bond with H and another element Very weak bond (5%) Easily broken Example: water molecules and surface tension

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

pH Describes acidity or alkalinity (basicity) of a solution Number of H+ ions or OH- ions in solution Biochemical reactions – sensitive to small changes Salt is a + and – charged ion bonded together.

pH scale Ranging from 0-14. Acid-below 7 Base-above 7 A neutral substance has a pH of 7.0 Average pH of blood 7.35 to 7.45

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

Organic Compounds Contain Carbon, Hydrogen and Oxygen Are large molecules Form covalent bonds Flammable

Inorganic Compounds Do not contain carbon Are small molecules Usually form ionic 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

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 chromosomes DNA and RNA assist with protein synthesis

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 ATP is found in the Mitochondria

The End!