Almost all of the molecules that make up your body are polymers, chains of subunits.

1. Almost all of the molecules that make up your body are polymers, chains of subunits. Each type of macromolecule is a polymer composed of a different type of subunit.

2. The subunits of the macromolecules we will examine are covalently-bonded. The covalent bonds between the subunits are always formed by a type of reaction called Dehydration Synthesis (making something while losing water).

3. During dehydration synthesis, a water molecule is lost, electrons are rearranged, and a new bond is formed between the subunits. This same type of reaction is used to join the subunits of each of types of large molecules (macromolecules) that make organisms what they are. The structure of each type of macromolecules is what determines how the molecules function in our bodies.

5. A carbohydrate is an organic compound that is composed of atoms of carbon, hydrogen and oxygen in a ratio of 1 carbon atom, 2 hydrogen atoms, and 1 oxygen atom. Some carbohydrates are relatively small molecules, the most important to us is glucose which has 6 carbon atoms. These simple sugars are called monosaccharides.

6. The primary function of carbohydrates is for short-term energy storage (sugars are for Energy). A secondary function is intermediate-term energy storage (as in starch for plants and glycogen for animals).

7. Other carbohydrates are involved as structural components in cells, such as cellulose which is found in the cell walls of plants.

8. Two common Monosaccharides, (single sugars) Glucose and Fructose Two Common Monosaccharides

9. Hooking two monosaccharides together forms a more complex sugar. Compounds such as sucrose are called Disaccharides (two sugars). Both monosaccharides and disaccharides are soluble in water.

10. Larger, more complex carbohydrates are formed by linking shorter units together to form long or very long sugar chains called Polysaccharides. Because of their size, these are often times not soluble in water.

11. Many biologically important compounds such as starches and cellulose are Polysaccharides. Starches are used by plants, and glycogen by animals, to store energy in their numerous carbon-hydrogen bonds, while cellulose is an important compound that adds strength and stiffness to a plant's cell wall.

12. Large polymers of sugars are called Carbohydrates.. The term Complex Carbohydrate, or sometimes even just Carbohydrate refers to long chains of sugars. Three common types of complex carb's are: Starch, Cellulose, and Glycogen.

13. All three are composed only of Glucose. They differ only in the bonding arrangements between the Glucose subunits. Not all complex carbs are composed of glucose alone, many have highly unusual sugars in their chains.

14. Starch • Starch is a long (100's) polymer of Glucose molecules, where all the sugars are oriented in the same direction. Starch is one of the primary sources of calories for humans.

15. Cellulose • is a long (100's) polymer of Glucose molecules. However the orientation of the sugars is a little different. In Cellulose, every other sugar molecule is "upside-down". This small difference in structure makes a big difference in the way we use this molecule.

16. Glycogen • is another Glucose polymer. Glycogen is a stored energy source, found in the Liver and muscles of Humans. Glycogen is different from both Starch and Cellulose in that the Glucose chain is branched or "forked".

17. Lipids • Each type of lipid has a slightly different structure, but they all possess a large number of C - H bonds which makes them a primarily non-polar group of molecules. All the C-H bonds also makes them very Energy-rich.

18. Function for Lipids is that of Energy storage. Lipids contain a lot of calories in a small space. Since Lipids are generally insoluble in polar substances such as water, they are stored in special ways in you body's cells. Lipids can also function as structural components in the cell. Phospholipids are the major building blocks of cell membranes.

19. Lipids are also used as hormones that play roles in regulating our Physiology (metabolism). Most lipids are composed of some sort of fatty acid arrangement.

20. Fatty Acids: • The lipid building blocks: The common building block for most of the different types of lipids is the fatty acid. • Fatty acids are composed of a chain of methylene groups with a Carboxyl functional group at one end.

21. The methyl chain is the fatty part, the Carboxyl, the acid. The fatty acid chains are usually between 10 and 20 Carbon atoms long. The fatty "tail" is non-polar (Hydrophobic) while the Carboxyl "head" is a little polar (Hydrophillic).

22. Fatty acids can be saturated(meaning they have as many hydrogens bonded to their carbons as possible) or unsaturated (with one or more double bonds connecting their carbons, hence fewer hydrogens).

23. A fat is a solid at room temperature, while an oil is a liquid under the same conditions. The fatty acids in oils are mostly unsaturated, while those in fats are mostly saturated.

24. Triglycerides: • Energy Storage, Three fatty acids bonded to Glycerol. Triglycerides are Energy-storage molecules. They are formed by connecting three fatty acids ( to Glycerol. • contain a lot of Energy (aka Calories). Fat has a lot of calories.

26. The flabby stuff most of us have on certain parts of our bodies is cells filled with triglycerides. In trigylcerides, a fatty acid is joined to each of the three Carbons of Glycerol by Dehydration Synthesis to form a molecule which stores a lot of calories in a small space.

27. Phospholipids • serve an extremely important function in our bodies, they form the cell membrane. Think of each cell as being surrounded by a fence, a fluid fence, but a fence none the less. It is called the the cell membrane or the plasma membrane. The cell membrane is composed of two layers, each composed of trillions of Phospholipid molecules oriented in a special manner

28. The most important feature of phospholipid structure is that the fatty acid "tails" are non-polar while the phosphate "head" is very polar. This leads to a chemically confused (solubilty-challenged) molecule. When exposed to an aqueous (water) environment, phospholipids form unique assemblies called "bilayers". The polar heads of the P-lipids turn toward the water molecules (Hydrophilic) while the non-polar tails hide from water molecules (Hydrophobic).

29. The structure that surrounds each of your cells (the plasma or cell membrane) is formed from a Phospholipid bilayer. The polar heads of the phospholipids are all facing the aqueous environments of the outside, and the inside of the cell, while the non-polar tails form a fatty layer on the inside This structure is an important barrier and defines the boundaries of living and unliving portions of a cell.