- body functions depend on cellular level

- cellular functions result from chemical changes

- biochemistry helps to explain physiological processes

* composed of chemically identical atoms

- Bulk elements: required by the body in large amounts

- trace elements: required by the body in small amounts

- ultratrace elements: required by the body in very minute amounts

Atom - smallest particle of an element that has properties of that element.

Electron - small with almost no weight and carries a negative charge, stays in constant motion around nucleus of atom.

Proton - large and carries positive charge within nucleus

Neutron - same weight as proton, uncharged (neutral) within nucleus

Ion - Particle that is electricall charged because gained/lost electrons

Molecule - Particle formed by the chemical union of two or more atoms.

Protons - single positive charge

Electrons - single negative charge

Neutrons - no electrical charge

Central part of an atom that is comprised of protons and neutrons.

Electrons move around the nucleus

The number of Protons in the nucleus of one atom.

Each element has a unique atomic number

Protons = # of electrons in an atom

Approximated by number of Protons and Neutrons in an atom because both have a weight of one.

Electrons do not contribute to the weight of the atom.

- Atoms with same atomic # but different atomic weights

- Different # of Neutrons

- Oxygen often form Isotropes (O¹⁶, O¹⁷, O¹⁸)

- Radioactive isotopes are unstable, releasing energy or pieces of themselves (atomic radiation)

(For an element, the atomic weight is often considered the average of the atomic weights of it's isotopes)

Depict the elements present and the number of each atom present in the molecule.

Examples: H₂  C₆H₁₂O₆  H₂O

- First electron shell can hold 2 electrons

- Second electron shell can hold up to 8 electrons

- Third electron shell can hold up to 8 electrons

An atom that gains or loses electrons to become stable.

An electrically charged atom.

A positively charged ion that is formed when an atom loses electrons

A negatively charged ion formed when an atom gains electrons.

Formed when atoms share electrons.

 i.e. two hydrogen atoms sharing 2 electrons 

Shows how atoms bond and are arranged in various molecules.

H - H = H₂

- Molecule with slightly negative end and slightly positive end

- Results when electrons are not shared equally in covalent bonds

- Water is an important polar molecule

- A weak attraction between positive end of one polar molecule and negative end of another polar molecule.

- Formed between water molecules

- Important for protein and nucleic acid structure

- Occur when chemical bonds form or break among atoms, ions, molecules

- Reactants are the starting materials for the reaction - the atoms, ions, or molecules

- Products are substances fomed at the end of the chemical reaction.

Substances that release ions in water

- Salts and minerals that can conduct electrical impulses in the body. Common human electrolytes are sodium chloride, potassium, calcium, and sodium bicarbonate. Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost every major biochemical reaction in the body.

Electrolytes that dissociate to release hydrogen ions in water

(HCI = H⁺ + Ci^-)

Substances that release ions that can combine with hydrogen ions.

(NaOH = Na⁺ + OH^-)

Electrolytes formed by the reaction between an acid and a base.

Indicates the concentration of hydrogen ions in solution.

-pH the symbol relating the hydrogen ion (H+) concentration or activity of a solution to that of a given standard solution.  pH 7 is neutral; above it alkalinity increases and below it acidity increases.

pH 7; indicates equal concentrations of H⁺ and OH^-

OH^- is hydroxide

Buffers

(chemicals which act to resist pH changes)

- Contain C and H

- Usually larger than inorganic molecules

- Dissolve in water and organic fluids

- Carbohydrates, proteins, lipids, nucleic acids

- Generally do NOT contain H and C

- Usually smaller than organic molecules

- Usually dissociate in water, forming ions

- Water, Oxygen, carbon dioxide, and inorganic salts

- Most abundant compound in living material

- Two-thirds of the weight of an adult human

- Major composnent of all body fluids

- Medium for most metabolic reactions

- Important role in transporting chemicals in the body

- Absorbs and transports heat

- Used by organelles to release energy from nutrients in order to drive cells metabolic activities

- Necessary for survival

- Waste product released during metabolic reactions

- Must be removed from body

- Abundant in body fluids

- Sources of necessary ions (Na⁺, Cl^-, K⁺, Ca⁺², etc.)

- Play important roles in metabolism

- Provide energy to cells

- Supply materials to build cell structures

- Water-soluble

- Contains C, H, and O

- Ration of H to O is close to 2:1 (C6H12O6)

- Monosaccharides: glucose, fructose

- Disaccharides: sucrose, lactose

- Polysaccharides: glycogen, cellulose

Triglycerides

(fats)

Used primarily for energy

Contain C, H, O but less Oxygen than carbohydrates

Building blocks are 1 glycerol and 3 fatty acids per molecule (saturated fats come from animals and are mostly solid.  Unsaturated fats come from plants and are mostly liquid.)

- Building blocks are 1 glycerol, 2 fatty acids, and 1 phosphate per molecules

- Hydrophilic and hydrophobic

- Major component of cell membranes

Fats used primarily for energy

Contain C, H, O but less Oxygen than carbohydrates

Building blocks are 1 glycerol and 3 fatty acids per molecule

Saturated fats come from animals and are mostly solid. 

Unsaturated fats come from plants and are mostly liquid.

- Type of Lipid

- Four connected rings of carbon

- Widely distributed in the body, various functions

- Component of cell membrane

- used to synthesize hormones

- cholesterol

- structural material

- energy source

- hormones

- receptors

- enzymes

- antibodies

- Primary Structure (amino acids join to from a polypetide chain)

- Secondary Structure (polypeptide chain either pleated or twisted to form a coil)

- Tertiary Structure (Pleated and coiled polypeptide chain folds to a unique 3 dimensional structure)

- Quaternary Structure (two or more polypeptide chains connected to form a single protein molecule)