CHEMICAL COMPOUNDS IN THE LIVING SYSTEM

Compounds
- a bigger molecule formed by atoms

2 Main Groups

Organic Compounds
- compounds that contain carbon atoms bonded to hydrogen or oxygen atoms

Inorganic Compounds
- compounds that lack carbon atoms


Inorganic Compounds

Water HOH
- 2/3 of our total body weight is water
- universal solvent

Acids
- releases one or more hydrogen ions (H+)
ex:
Hydrochloric acid (HCI)
Sulfuric acid (H2So4)

Base or Alkaline
- releases one or more hydroxyl ions (OH-)
ex:
Sodium hydroxide (NaOH)
Ammonium hydroxide (NH4OH)

pH Scale
- measures how acidic or how basic a substance is.
0-6 : substance is acidic
ex: battery acid
7 : neutral
ex: water
8-14 : substance is basic
ex: baking soda

buffers - resist changes in the pH of the chemical system
*Important Biological Buffers
- bicarbonates
- phosphates
- organic molecules (amino acid)

Salts
- form when an acid and a base react.
- hydrogen ion+hydroxyl ion = salt (table salt)+water

Neutralization Process - positive ion of an acid reacts with the negative ion of a base


Organic Compounds

Carbohydrates : compounds contaning carbon, hydrogen, and oxygen in the ration of 1:2:1

Monosaccharides - simplest form of carbohydrates
- glucose, fructose, and galactose are examples

Glucose
- most common hexose in the body
- sometimes reffered to as blood sugar, dextrose, and grape sugar
- indespensable component of blood

Fructose
- sugar that accounts for the sweeteness of ripened fruits

Galactose
- monosaccharides found in milk

Five-carbon sugars (pentose)

Ribose
- important component of ribonucleic acid (RNA)
Deoxyribose
- important component of deoxyribonucleic acid (DNA)


Disaccharides
- reffered to as the double sugars
- made up of two monosaccharide units
Dehydration Synthesis
- formation of a disaccharide from 2 monosaccharide units with the
removal of a water molecule

Examples:

Maltose (malt sugar)
-formed by the reaction of 2 glucose units

Sucrose
- common table sugar
- formed by the reaction of one molecule of glucose and one molecule of fructose

Lactose
- milk sugar
- formed when one molecule of glucose reacts with one molecule of galactose

Polysaccharides
- composed of a large number of monosaccharide units

Starch
- common component of plant protoplasms
- soluble in water

Glycogen
- found in bodies of animals
- excess glucose units stored temporarily

Cellulose
- similar to starch
- insoluble in water
- part of the plant cell wall


Lipids : composed of carbon, hydrogen, and oxygen but contain much less oxygen in proportion to carbon and hydrogen

2 Basic Units

Glycerol
Fatty acids

2 Kinds of Fats

Saturated Fats
- are solid at solid temperature
- examples are butter, lard, and animal fats
- promotes a condition called atherosclerosis

Unsaturated Fats
- remain liquid at room temperature
- not harmful to one's health
- examples are corn oil, olive oil , and other vegetable oils.


Proteins
- most diverse in the structure and function among organic compounds

peptide bond - formed between the amino group of amino acids and the carbon group of the next
amino acid.

Classes of Proteins

a. Structural Protein e. Transport Protein
b. Contractile Protein f. Hormonal Protein
c. Storage Protein g. Receptor Protein
d. Defensive Protein h. Catalytic Protein


Nucleic Acid
- serve as blueprints for proteins that ultimately control the chemical processes in a cell.
- nucleotide is composed of a five-carbon sugar, a phosphate group, and a
nitrogen-containing base pair.