Anatomy and Physiology - basic chemistry

Elements

Substances that cannot be broken down into something simpler

96% of all living matter is made up of just four elements

Carbon, oxygen, hydrogen, and nitrogen

Trace elements

Required only in minute quantities

Radioactive isotopes

their nuclei decay spontaneously

Valence shell

The chemical behavior of an atom depends on the number of electrons in its outermost shell

3 main chemical bonds

Covalent bond, Ionic bond, Hydrogen bond

Covalent bond

occurs when a pair of valence electrons is shared between two atoms (very strong)

Electronegativity

A particular bond has a stronger pull on the shared electrons than other atoms

Nonpolar

electrons shared equally

Polar

electrons shared, but not equally

Ionic bond

formed when one atom is so electronegative that it strips an electron completely away from another atom

Anion

the atom that gains the electron and has a negative charge

Cation

the atom that loses the electron, and has a positive charge

Chemical Reactions

form or break chemical bonds

Decomposition

reactions break chemical bonds and release energy

Synthesis

reactions form chemical bonds and must absorb energy to occur

Particle size

the smaller the particle, the faster the reaction

Temperature

the higher the temperature, the faster the reaction

Concentration

the greater the number of particles in a given space, the faster the reaction

Catalyst

catalysts increase the rate of a chemical reaction (enzymes)

Inorganic molecules

do not contain carbon except for (CO2)

smaller

dissolve in water or react with it to release ions

includes oxygen, carbon dioxide, water, salts, acids, and bases

Organic molecules

contains carbon and hydrogen

larger

includes carbohydrates, lipids, proteins, and nucleic acids

Carbon Dioxide

by-product of metabolism

reacts with water to form carbonic acid

is removed from the body via respiration

Oxygen

required for cellular respiration

Water (polar)

solvent

provides site for most metabolic reactions

absorbs and releases heat slowly

provides excellent cooling

major component of mucus

major component of cells (52-70%)

Buffer

a substance that minimizes a charge in pH, donates H+ when in excess

Organic molecules

most are polymers made of monomer building blocks

Disachharide

a dehydration reaction can be used to link together two monosaccharides (sucrose, lactose, maltose)

Polysaccharides

thousands of monosaccharides

Glycogen

the main polysaccharide made by the human body and is a glucose polymer

Proteins

C,H,O,N, and S

the monomers for building proteins are amino acids, held together by peptide bonds

Amino acids

two functional groups ( carboxyl and amino groups )

Proteins functions

structural molecules, defense molecules, storage, transport, communication, movement, and hormones

Denature

extreme conditions can cause proteins to lose their 3D shape

Causes of denaturation

extreme temps, harsh elements, high salt concentrations

Nucleotides

the monomer of nucleic acids