MACROMOLECULES

MOLECULAR CHAINS Formed by bonding small molecules [monomers] together into chains called polymers

These larger molecules, macromolecules, may be composed of thousands of atoms. The 4 major classes of macromolecules are: carbohydrates, lipids, proteins, & nucleic acids.

Carbohydrates – Carbohydrates are compounds composed of carbon, hydrogen, and oxygen, with the general molecular formula CH2O. CARBOHYDRATES

Three Types: Monosaccharides – A simple sugar or carbohydrate which cannot be broken down any further. Its molecular formula is C6H12O6, & the most common is glucose. Glucose

Three Types: B) Disaccharide – A double sugar or a combination of two simple sugar molecules. Sucrose, maltose, and lactose are disaccharides.

Lactose

Plants can store surplus glucose in starch and withdraw it when needed for energy or carbon. Animals that feed on plants, especially parts rich in starch, can also access this starch to support their own metabolism. Starch is a storage polysaccharide composed entirely of glucose monomers. One function of polysaccharides is as an energy storage macromolecule that is hydrolyzed as needed. C) Polysaccharide – A polysaccharide is a complex compound composed of a large number of glucose units. Examples are starch, cellulose, and glycogen. Starch granules in potato tuber cells Glucose monomer STARCH GLYCOGEN CELLULOSE Glycogen granules in muscle tissue Cellulose fibrils in a plant cell wall Cellulose molecules

Animals also store glucose in a polysaccharide called glycogen. Humans and other vertebrates store glycogen in the liver and muscles but only have about a one day supply.

Structural polysaccharides form strong building materials. Cellulose is a major component of the tough wall of plant cells.

Cellulose in our food passes through the digestive tract, stimulating the secretion of mucus, and is eliminated in feces as “insoluble fiber”. Some microbes can digest cellulose to its glucose monomers through the use of cellulase enzymes. Many eukaryotic herbivores, like cows and termites, have symbiotic relationships with cellulolytic microbes, allowing them access to this rich source of energy.

Another important structural polysaccharide is chitin, used in the exoskeletons of arthropods (including insects, spiders, and crustaceans). Chitin also forms the structural support for the cell walls of many fungi.

Lipids Lipids are organic compounds that dissolve poorly, if at all, in water (hydrophobic). The unifying feature of lipids is that they all have little or no affinity for water. This is because their structures are dominated by nonpolar covalent bonds. Fatty Acids Saturated MonoUnsaturated PolyUnsaturated

A fat is constructed from two kinds of smaller molecules, glycerol and fatty acids.

Most animal fats are saturated fats which are solid at room temperature. A diet rich in saturated fats may contribute to cardiovascular disease (atherosclerosis) through plaque deposits.

Fats with unsaturated fatty acids are unsaturated fats. Plant and fish fats, known as oils, are liquid at room temperature.

The major function of fats is energy storage. A gram of fat stores more than twice as much energy as a gram of a polysaccharide. Humans and other mammals store fats as long-term energy reserves in special cells. Fat also functions to cushion vital organs.

A layer of fats can also function as insulation A layer of fats can also function as insulation. This subcutaneous layer is especially thick in whales, seals, and most other marine mammals. Blubber

Lipid Types Chart

Phospholipids have two fatty acids attached to glycerol and a phosphate group.

The interaction of phospholipids with water is complex. The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head.

When phospholipids are added to water, they self-assemble into aggregates with hydrophobic tails pointing toward the center and hydrophilic heads on the outside.

Phospholipids are the major component of membranes.

Lipid Types Chart

Stabilizes the cell membrane Cholesterol Stabilizes the cell membrane

Cholesterol lipids

Lipid Digestion Animation http://www.wiley.com/college/boyer/0470003790/animations/fatty_acid_metabolism/fatty_acid_metabolism.htm

PROTEINS a.k.a. “PolyPeptides”

PROTEINS Proteins are composed of carbon, hydrogen, oxygen, nitrogen, and sometimes phosphorus and sulfur. Approx. 50% of the dry weight of living matter is protein.

PROTEINS Proteins are instrumental in about everything that an organism does. These functions include structural support, and are the enzymes that break and construct products in our bodies

PROTEINS Proteins are instrumental in about everything that an organism does. Proteins are the overwhelming # of enzymes in a cell and break down and put together materials in the body.

What are proteins made out of? Humans have tens of thousands of different proteins, each with their own structure and function. What are proteins made out of? I’m not sure

Amino acids are the building blocks of all proteins. a.a.

Condensation synthesis Amino Acids Amino acids are assembled into chains by means of peptide bonds. Amino acid Dipeptide Condensation synthesis Carboxyl group Amino group PEPTIDE BOND

Peptide Bond = A bond between two amino acids. PEPTIDE BONDS Peptide Bond = A bond between two amino acids.

Proteins in the 3rd Dimension The primary structure of a protein is its unique sequence of amino acids. Each protein is a different sequence!

Protein that speeds up a chemical reaction ENZYMES Protein that speeds up a chemical reaction *Involved in nearly all metabolic processes.

Enzymes lower the amount of activation energy needed for a reaction, allowing it to occur more rapidly. The enzyme binds with the substrate but resumes its original conformation after forming the enzyme-substrate complex.

ENzYMe ANIMATIONS http://www.kscience.co.uk/animations/anim_2.htm

FACTOR EFFECT EXPLANATION

Nucleic Acids – long polymers involved in heredity and in the manufacture of different kinds of proteins. The two most important nucleic acids are DNA and RNA. DNA

Nucleotides – These are the building blocks of nucleic acids Nucleotides – These are the building blocks of nucleic acids. Nucleotides are complex molecules composed of a nitrogenous base, a 5-carbon sugar, and a phosphate group.                                                                                                    DNA

DNA – Chromosomes and genes are composed mainly of DNA DNA – Chromosomes and genes are composed mainly of DNA. It is composed of Deoxyribose, nitrogenous bases, and phosphate groups. DNA

The 4 Nitrogenous Bases Of DNA Thymine CH3 NH2 N H O Cytosine Sugar O OH Phosphate Group Nitrogenous Base The 4 Nitrogenous Bases Of DNA Double Bond Triple Bond Guanine N HN H H2N O Adenine NH2 N H

RNA RNA – is involved in protein synthesis. Unlike DNA, it is composed of the sugar ribose and the nitrogenous base uracil instead of thymine.

ESSAY QUESTION Describe the four major groups of organic compounds that compose the human body. Include their chemical make-up in your essay, but focus on their function and importance to organic life forms.