Chapter 2

Chemistry of Life

Water has many properties that make it unique.

1. Strong Polarity- Many materials dissolve in water to be transported to every organ of the body. (Oxygen and carbon dioxide)

2. High Specific Heat- Allows the body to maintain body temperature

3. High heat of vaporization- allows evaporation of water to cool the body.

4. Cohesion- water works as a lubricant or cushion to protect against damage from friction or trauma.

Properties of Water

Electrolytes are substances that break up or dissociate in solution to form charged particles or ions.

Cations carry a _________charge Anions carry a ____________charge

Acids, bases and salts are electrolytes in the body.

Electrolytes

Acids- release Hydrogen ions in water (proton donors)

Bases- increase Hydroxide (OH-) ion in water (proton acceptors)

Bicarbonate ion is an important base that plays a critical role in the transportation of respiratory gases and elimination of wastes.

Electrolytes cont…

Normal pH in the body ranges from a pH of 7.36 in venous blood to 7.41 in arterial blood.

CO2 is carried as carbonic acid (H2CO3). This compound along with bicarbonate work together to maintain the blood pH within this narrow range.

Buffers

Results from interaction of acids and bases. Salts are required for proper function of muscles and nerves.

Sodium, potassium, calcium and magnesium are major players in muscle and nerve function.

Salts

STRAIGHT CHAINS BRANCHED CHAINS RINGS

The Role of Carbon in Organisms Carbon is found in ALL living things.

Carbon has 4 electrons for bonding in the outer energy shell, which allow carbon to take on many forms.

Compounds containing Carbon are ORGANIC compounds.

Bonding

ISOMERS- compounds with the same chemical formula but different structures

Monomers- single molecules – for example a monomer of glucose. (mono = means one)

Polymer- large molecules bonded together (poly = means many)

Monomers JOIN to form Polymers

Biomolecules- Large organic molecules.

POLYMER

Small molecules join by CONDENSATION. When water condenses it falls out of the molecule and joins the 2 small molecules together.(aka Dehydration synthesis)

Large molecules break apart by HYDROLYSIS- hydro=water, lysis=to break. Therefore when water is added and breaks the polymer apart.

ENERGY FOR CELLS Composed of Carbon, Hydrogen and Oxygen 1:2:1 ratio of C:H:O Forms

◦ Monosaccharides (one sugar)◦ Disaccharides (two sugars)◦ Polysaccharides (multiple sugars)

Glucose is a carbohydrate

CARBOHYDRATES

Carbohydrate storage:1. Starch

2.Glycogen in the liver

3. Cellulose carbohydrate storage in plants

Very important to cell membrane Function;

◦ Energy storage◦ Insulation◦ Protective coating.

Examples: fats , oils, and steroids

Lipids are glycerols attached to fatty acids

LIPIDS

Saturated Fatty Acids (FA) have all single bonds between carbon molecules and contain as many hydrogens as possible

Unsaturated Fatty Acids contain one double bond between 2 of the carbon molecules in the chain.

Polyunsaturated Fatty Acids have multiple double bonds between carbon molecules.

Hydrogen saturation

Glycerol molecule

Cholesterol can travel through the blood if it is attached to a protein molecule. Some of these are HIGH DENSITY LIPOPROTEINS (HDL) because they have a high density of protein.

Others have a LOW DENSITY LIPOPROTEIN and consequently a higher amount of lipid or Fat.(LDL).

High LDL causes fatty deposits in the arteries. This is called bad cholesterol.

High HDL can actually remove fat and is called good cholesterol.

Blood Lipoproteins

Essential to all life Function:

◦ Provides structure for tissues◦ Carry out cell metabolism

Composed of C, H, O, NITROGEN and sometimes SULFUR

PROTEIN

Building blocks of protein 20 common A.A. that combine to form

thousands of proteins. Bonds between A.A. are called PEPTIDE

BONDS. A.A. fold and bend on each other forming

complex structures that make proteins.◦ Primary, Secondary and Tertiary forms of proteins.

Bends and folds within the charges of the amino acids.

Amino Acids (A.A.)

Transport Oxygen to blood stream Immunity Contract Muscle Tissue Regulate other proteins Carry out Chemical Reactions ENZYMES-act like a lock and key, when key

is in place the reaction is quickly carried out.

(Video)

Role of Protein

ENZYME ACTION

Proteins that control reactions within the body. Essential to the function of the body.

Enzymes are catalysts that are not used in the reaction. They only provide the stage on which the reaction can occur.

Enzymes

Polymers of a smaller subunit called a NUCLEOTIDE

Nucleotides are made of C,H,O,N and P. Three basic parts

Nucleic Acids

DNA and RNA are nucleic acids Code to form all of an organisms make up Nucleotides join to form DNA

Nucleic Acids cont…