Chapter 2 Section 3

Carbon

• The main ingredient of organic molecules• Life w/o Carbon is as unlikely as life w/o

H2O• Atomic # 6

– 6 PROTONS– 6 NEUTRONS– 6 ELECTRONS

• CAPABLE OF 4 BONDS

• Most carbon based molecules are classified as organic molecules. – Non carbon based molecules are inorganic

molecules.

• Carbon can be bound with other carbons to form carbon “backbones” or “skeletons”

NO, Like This……

Monomers and Polymers

• Many bio-molecules are made of hundreds of atoms.

• These large molecules are built of monomers - similar units used to build large molecules.

• Many monomers linked together are called polymers – long chains of monomers

Life’s Macromolecules

• Broken down into four categories1. CARBOHYDRATES

2. LIPIDS

3. PROTEINS

4. NUCLEIC ACIDS

CARBOHYDRATES

• Carbohydrate – an organic compound made of sugar molecules.– Sugars contain Carbon, Hydrogen, and

Oxygen in a 1:2:1 ratio• Example Glucose C6H12O6

• Monosaccharide – simple sugar containing 1sugar unit.– Examples: glucose, fructose, galactose

• Glucose is the main fuel supply for cellular work.– Broken down for energy– Carbon skeletons reused to make other kinds

of organic molecules.– Glucose not immediately used may be

incorporated into larger carbohydrates or used to make fat.

• Disaccharides – double sugar. Two monosaccharides bonded together. – Example: Sucrose – carbohydrate found in plant sap,

table sugar, maple syrup.• Glucose + Fructose

• Polysaccharides – long polymer chains made up of simple sugar monomers.– Examples:

• Starch• Glycogen• Cellulose

STARCH

• Found in plant cells– Foods high in starch

• Potatoes• Corn • Rice• Wheat

WHO WANTS

A CRACKER?

GLYCOGEN

• Polysaccharide found in animal cells.– Stored in granules in the liver and muscle

cells

Cellulose• Polysaccharide found in plants

– Protects cells– Gives structure– Made of glucose monomers– Commonly referred to as fiber

Cellulose cont.• Most animals, including humans, can’t

digest cellulose– Keeps digestive tract healthy – Does not act as a nutrient

Cellulose cont.

• Cows and horses can digest cellulose thanks to microorganisms living in their stomachs or intestines that break it down for them.

• Almost all carbohydrates are hydrophilic – Hydrophilic – like water, can be dissolved in

water

• Many monosaccharides and disaccharides dissolve in water

• Cellulose does not– Too big– If it did we wouldn’t be able to do laundry

• Cotton T-shirts and jeans would dissolve.

Lipids• A class of water avoiding compounds

– Hydrophobic• This property of lipids

is important for their

function.

Functions of Lipids

• Some types can act as boundaries that surround and contain the aqueous contents of cells.

• Some types can circulate in the blood and act as chemical signals to cells

• Other types, known as fats, store energy in your body.

Fats

• Consist of a 3-carbon backbone called glycerol attached to three fatty acids each with long hydrocarbon chains.

• Some fats are solid at room temperature.

• Others called oils are liquids at room temperature.

• In addition to storing energy, fats cushion organs and provide body with insulation.

Saturated vs Unsaturated• Saturated - a fat in which all three fatty acid chains

contain the maximum possible # of hydrogen atoms.– All carbons in the chain form single bonds with each

other.– The rest of their bonds are with hydrogen atoms

Saturated vs Unsaturated• Most animal fats such as lard and butter are

saturated fats.• Unsaturated – at least one chains contains less

than the maximum # of hydrogens.

Saturated vs UnsaturatedDiets rich in saturated fats may be unhealthy– May promote buildup of lipid-containing

deposits, called plaques, within blood vessel walls.

– May reduce blood flow and contribute to heart disease.

Other types of Lipids

• Waxes• Steroids• Cholesterol• Hormones

Proteins

• Composed of long chains of amino acids– Amino acids – the building blocks (monomers)

of proteins• 20 different amino acids• Proteins differ only by the # AND

arrangement/combination of amino acids• Example:

– English Alphabet» 26 letters combined in various combinations form

thousands and thousands of words.

Protein Functions• 2 Main Functions

– Structural – Enzymes

1. Structural• Many proteins form structural molecules• Examples:

• Cartilage & Tendons are made of proteins called collagen.

• Hair, Feathers, and Parts of cells are all made of proteins.

Protein Functions cont.

2. Enzymes• Proteins that increase the rate of chemical reactions

taking place in your body.• They do this by lowering the amount of energy required to

start the reaction

PROTEIN STRUCTURE• Proteins have a 3D shape that supports their

functions.• Denaturation: When a protein’s shape is

altered to a point that the protein can no longer function properly.

*********YOU NEED TO ADD THIS TO YOUR NOTES PAGE*******

Enzymes reduce amount of energy needed for chemical reactions to take place.

So what is energy?

The ability to do work.

2 Kinds

Potential (stored energy)

Kinetic (energy of motion)

Nucleic Acids• 2 types

– DNA Deoxyribonucleic Acid– RNA Ribonucleic Acid

• Nucleic acids are made of nucleotides– Nucleotides - the building blocks (monomers)

of nucleic acids.

DNA• Double helix

– 2 interlocking , coil shaped strands

• Forms units of inheritable information called genes

• Contains directions

for everything that

goes on in you.

RNA• Single strand made from DNA

• 3 types

• Major responsibility is protein synthesis– Making proteins