Ch. 2 – The Chemistry of Life Section 2-3 Carbon Compounds or A Brief Introduction to Organic Chemistry

Carbon

Why Carbon? What makes carbon (C) the basis of all living things? Carbon has 4 valence electrons (remember that valence electrons are the ones available for bonding with other atoms). This means carbon (C) can bond with many elements including hydrogen (H), oxygen (O), phosphorus (P), sulfur (S), and nitrogen (N).

Why Carbon? (continued) What makes carbon (C) the basis of all living things? Carbon can also bond to other carbon atoms giving them the ability to make chains that are almost unlimited in length. No other element has the versatility of carbon (it’s a kind of “Swiss Army knife”).

Why Carbon? (continued) Carbon bonds are very stable Carbon bonds contain a lot of energy

Why Carbon? (continued) Carbon-carbon bonds can be single, double, or triple bonds CC Single bond C C C C +

Why Carbon? (continued) Carbon-carbon bonds can be single, double, or triple bonds CC Double bond C C C C +

Why Carbon? (continued) Carbon-carbon bonds can be single, double, or triple bonds CC Triple bond C C C C +

Why Carbon? (continued) Carbon compounds come in a wide variety of shapes – like chains, rings and sheets. AcetyleneButadieneBenzeneIsooctaneMethane

carbon rings

graphite

Fatty acids – carbon “chains”

Cellulose – carbon “sheet”

“Buckyballs”

Macromolecules Carbon is good at making macromolecules. –Macromolecules are “giant molecules”. Macromolecules are formed by joining huge numbers of small units together. The small units are called monomers. –The monomers subunits may be identical or different.

Macromolecules The giant molecules are polymers. The process of connecting the little monomers into huge macromolecules is known as polymerization.

Macromolecules (continued) There are four (4) main groups of organic macromolecules: –Carbohydrates –Lipids –Nucleic acids –Proteins

Carbohydrates Carbo- (carbon) Hydrate (water) CH 2 0 units –1 C : 2 H : 1 O

Carbohydrates Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes.

Carbohydrates The monomers (small subunits) that make up large carbohydrates are called simple sugars (monosaccharides). Polysaccharides are large carbohydrate macromolecules made up of many monosaccharide monomers.

Monosaccharides Two of the most important and common monosaccharides are glucose and fructose. Both have the chemical formula C 6 H 12 O 6, but have different shapes.

Macromolecules (continued) There are four (4) main groups of organic macromolecules: –Carbohydrates –Lipids –Nucleic acids –Proteins

Lipids Common categories of lipids are: –Fats –Oils –Waxes Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings.

Lipids Lipids contain mostly C and H atoms.

Lipids Many lipids are formed when a glycerol molecule combines with fatty acids. (see pg. 46 in text)

Saturated Fats Saturated fats are those that contain the maximum number of H atoms (think “saturated with H”). –Another way of thinking about saturated fats is that they have all single C-C bonds.

Lipids Unsaturated fats are those that contain at least one C=C double bond. Polyunsaturated fats are those lipids with multiple C=C double bonds.

Saturated vs. Unsaturated Fats The chains in unsaturated fatty acids are “kinked”.

Fat versus Oil FAT  Fully saturated  Straight chains  Solid at room temp. OIL  Unsaturated  Kinked chains  Liquid at room temp.

Why do you think saturated fats are solids at room temperature while unsaturated fats are liquids at room temperature? Are you pondering what I’m pondering?

Do you think that all parts of a lipid molecule are equally attracted to water molecules? Are you pondering what I’m pondering?

Macromolecules (continued) There are four (4) main groups of organic macromolecules: –Carbohydrates –Lipids –Nucleic acids –Proteins

Nucleic acids Nucleic acids contain O, N, C, and P. Nucleic acids are huge polymers assembled from small monomer units called nucleotides.

Nucleic acids Nucleic acids store and transmit hereditary, or genetic, information. There are two kinds of nucleic acids: –Ribonucleic acid (RNA) –Deoxyribonucleic acid (DNA)

Nucleic acids DNA and RNA have different sugar molecules at their core (deoxyribose, ribose). (structure pg. 47)

Macromolecules (continued) There are four (4) main groups of organic macromolecules: –Carbohydrates –Lipids –Nucleic acids –Proteins

Proteins Proteins are macromolecules that contain N (nitrogen), C, H, and O. Polymers of amino acids

Proteins Proteins are very diverse. This is because there are more than 20 different amino acids that can be arranged in any order in a protein. –See pg. 47 for amino acid structures. The varying part of amino acids is called the R-group. Amino Acid Structure Amino group Carboxylic acid group Variable portion, “R” group

The structure of the twenty amino acids

amino acids

Types of proteins Some proteins control the rate of reactions and regulate cell processes (enzymes are biological catalysts). Some are used to form bones and muscles. Others transport substances into or out of cells Still others help to fight disease (antibodies).

Biological Macromolecules - Summary Carbon Compounds include that consist of which contain that consist of which contain CarbohydratesLipidsNucleic acidsProteins Sugars and starches Fats, oils, waxes NucleotidesAmino Acids Carbon, hydrogen, oxygen Carbon, hydrogen, oxygen Carbon,hydrogen, oxygen, nitrogen, phosphorus Carbon, hydrogen,oxygen, nitrogen,

End 2-3

Why Carbon? (continued) Carbon-carbon bonds can be single, double, or triple bonds CC Triple bond C C C C +

Saturated & Unsaturated F.A.

Biological Macromolecules Carbon Compounds include that consist of which contain that consist of which contain CarbohydratesLipidsNucleic acidsProteins Sugars and starches Fats and oilsNucleotidesAmino Acids Carbon, hydrogen, oxygen Carbon, hydrogen, oxygen Carbon,hydrogen, oxygen, nitrogen, phosphorus Carbon, hydrogen,oxygen, nitrogen,