Lesson Topic 1.2: Basic Chemistry related to the Human Body Flashcards
chemical
fundamental unit in chemistry
elements total
112
118 in book
elements present in human body
26
4 major elements 96%
oxygen
hydrogen
carbon
nitrogen
atom
smallest unit of an element
atom contain
Nucleus that has protons (+), neutrons (0)
Electrons (–) surrounding nucleus
Total charge is neutral:
Protons # = electron #
Atomic number
equals the number of protons that also equals the number of electrons
atomic mass number
equals the number of protons and number of neutrons
Ion
When an atom that has a positive or negative charge bc it has unequal numbers of protons and electrons
molecule
atoms share electrons
compound
2 or more different atoms held together with chemical bonds
Types of chemical bonds
Ionic
Covalent
Hydrogen
Chemical reaction
Occur when old bonds break and new bonds form
Chemical reaction types
Synthesis
Decomposition
Exchange
Reversible
snythesis
2 or more atoms, joins, or molecules combine to firm new and larger molecules
decomposition
split up large molecules into smaller atoms, ions, or molecules
exchange
in the body.
consist of both synthesis and decompostion
reversible
the products can revert by two half-arrows pointing in oppostite directions
inorganic compounds
Structure: lack C-H bonds; structurally simple
Examples
Water, carbon dioxide, bicarbonate, acids, bases, and salts
WATER
Most abundant chemical in human body
Good solvent and lubricant
Takes part in chemical reactions
Absorbs and releases heat slowly; regulates body temperature
Involved in digestion, circulation, and elimination of wastes
Organic Compounds
Structure:
All contain C-H bonds
Structurally complex (include polymers composed of many units = monomers)
Classes: carbohydrates, lipids, proteins, nucleic acids
pH Concept
The concentration of H+ or OH– expressed on the pH scale
pH scale: 0–14
pH 7.0: H+ concentration = OH– concentration
pH < 7.0 = more H+ (acid)
The smaller the number, the more H+
pH > 7.0 = more OH– (alkaline)
The larger the number, the more OH–
more PH Concept
pH 7.0: H+ concentration = OH– concentration
pH < 7.0 = more H+ (acid)
The smaller the number, the more H+
pH > 7.0 = more OH– (alkaline)
The larger the number, the more OH–
Buffering System-
Even though strong acids and bases may be taken into the body or be formed by body cells, the pH of fluids inside and outside cells remains almost constant.
Buffers
Chemical compounds that act quickly to temporarily bind H+, removing the highly reactive, excess H+ from solution but not from the body.
