KEY CONCEPT Carbon-based molecules (proteins, lipids, carbohydrates and nucleic acids) are found in all organisms. These molecules form the structures and carry out the functions in all living organisms.

Why is Carbon so special? Carbon has four valence electrons. It shares these electrons with other atoms to form molecules that are held together by strong covalent bonds. .

Molecules that contain carbon are called Organic compounds Molecules that contain carbon are called Organic compounds. There are over 2 million known organic compounds. They are made and found only in living things.

3 basic shapes of carbon-based compounds straight chain branched chain ring

Monomers and Polymers

Large carbon-based molecules are made of many repeating small subunits joined by chemical bonds.

The smaller molecules are called Monomers Ex. Glucose

Larger molecules formed by joining monomrers are called Polymers.

Polymers can be made of the same repeating molecule

OR, polymers can be made by combining different monomers

=MONOMER – one train car =POLYMER – the whole train

The reaction that joins monomers to form polymers is called Dehydration Synthesis. Animation Dehydration synthesis means “to make by removing water.” (Dehydration – remove water Synthesis – to make)

Dehydration Synthesis

Polymers can be broken down into the monomers through Hydrolysis Hydrolysis means “to break by adding water”

Dehydration synthesis – builds bigger molecules Hydrolysis – breaks down bigger molecules They are opposite reactions!

Four major groups of organic compounds in living things: Carbohydrates Lipids Proteins Nucleic Acids

Quick Check for Understanding – What atom do all these molecules contain?

CARBON Quick Check for Understanding – What atom do all these molecules contain? CARBON

Where do we get these molecules? (Click for video) FROM OUR FOOD!!

CARBOHYDRATES

Types of Atoms in Carbohydrate molecules: Carbon (C), Hydrogen (H), and Oxygen (O)

Foods that contain primarily carbohydrate molecules are called Sugars and Starches

Uses in Living Things 1. “Quick” Energy 2. Builds body structures

3 Categories of Carbohydrates based on Size: Monosaccharides (smallest) Monomers 2. Disaccharides 3. Polysaccharides (largest) Polymers

1. Monosaccharide: one single molecule 1. Glucose – made in photosynthesis; blood sugar 2. Galactose - Component of milk sugar 3. Fructose - fruit sugar 4. Deoxyribose and Ribose – in nucleic acids DNA and RNA glucose

2. Disaccharide – 2 monosaccharides joined together 1. Sucrose – table sugar (glucose + fructose) 2. Lactose – milk sugar (glucose + galactose) fructose glucose

3. Polysaccharides - many monosaccharides joined together 1. Starch – glucose storage in plants (bread, taters) 2. Glycogen – glucose storage in animals 3. Cellulose – forms plant cell walls 4. Chitin – forms insect exoskeletons and fungus cell walls glucose cellulose

Carbohydrate molecules can have the same monomers but be joined together differently . Polymer (starch) Starch is a polymer of glucose monomers that often has a branched structure. Polymer (cellulose) Cellulose is a polymer of glucose monomers that has a straight, rigid structure monomer

Ex.s of different monomer arrangements

Chitin – forms rigid insect bodies Monomer Polymer

The structure of a molecule affects its function REMEMBER A UNIFYING THEME: The structure of a molecule affects its function

LIPIDS (Fats, Oils, Waxes)

Types of Atoms: C, H, O

Uses of Lipids in Living Things: Stores large amounts of chemical energy Provide warmth and insulation 3. #1 component of cell membranes 4. Make hormones the body’s chemical messengers

Common Features of Lipids 1. Nonpolar molecules – no charge on atoms 2. Hydrophobic – Can’t dissolve in water 3. Many lipids contain fatty acid molecules.

Fatty acid molecules share same basic structure

3 Categories of Fatty Acids No double bonds between Carbon atoms No kinks One or more double bonds between carbon atoms Molecule has kinks and bends

If the Fatty Acid molecules have : Single bonds between C atoms – Saturated Fats (Bad fats in diet) Double bonds between C atoms – Unsaturated Fats (Good fats in diet)

Blood Cholesterol Count LDL - Lousy for you Want # to be LOW HDL - Happy for you Want # to be HIGH

Dangers of Saturated Fats (Video)

Get in the habit of checking food labels for fat content

Categories of Lipids and their Functions: Triglycerides - Provide Energy

Categories of Lipids and their Functions: 2. Phospholipids – make cell membranes

Has negative charge Molecules have no charge

3. Sterols/Steroids – make hormones

4. Waxes – protective coating on skin and leaves (leaf cuticle) to prevent water loss

Types of Atoms in Protein Molecules: C, H, O, N, S

Uses of Proteins in Organisms: Enzymes – Speed up chemical reaction times Transport molecules through cells Antibodies in immune system Workhorses of the cell!

Monomers of Proteins: Amino Acids 20 different amino acid molecules 9 amino acids are Essential – Can only be obtained by eating food

Basic structure of all 20 amino acids Variable group Amine group Carboxylic acid group

Amino acids are joined by peptide bonds which form between them through dehydration synthesis . OH + H OH + H

The sequence, or order, of amino acids is called the “primary structure” – this is what determines a protein’s structure and function

. Amino Acids – Monomer Protein – Polymer

Ex.s of Protein Molecules in Organisms 1. Albumin – protein in egg white 2. Amylase – breaks apart starch to glucose through hydrolysis. Enzyme found in your saliva 3. Keratin – protein in hair, feathers and nails 4. Hemoglobin – in red blood cells, oxygen attaches to it to be carried throughout the body and delivered to all cells

NUCLEIC ACIDS DNA and RNA

Types of Atoms in N.A.: C, H, O, N, P

Two Types of Nucleic Acid Molecules 1. Deoxyribonucleic Acid - DNA 2. Ribonucleic Acid – RNA

Uses of Nucleic Acids 1. Stores hereditary information needed to make protein molecules by the cell

Monomers of Nucleic Acids Nucleotides – made of 3 molecules joined together

2. 1000’s of nucleotides join together to make DNA/RNA.

3 Molecules Join to form a Nucleotide 1. Sugar 2. Phosphate group 3. Nitrogen containing base (5 kinds). A phosphate group nitrogen-containing molecule, called a base deoxyribose (sugar)

Types of Nitrogen Containing Bases in: DNA RNA Adenine A Uracil U Guanine G Cytosine C Adenine A Thymine T Guanine G Cytosine C

In Summary: The majority of molecules in living things are either: Inorganic – ex. Water OR Organic – ex. Carbohydrates, Lipids, Proteins, Nucleic Acids The chemical basis of life is a Unifying Theme for all organisms