Fig. 2.3 Negligible mass Each has a +1 atomic mass unit Carbon is quite unique in that it only has 4 valence electrons, which means that it would like to share another 4 e- to satisfy the “Octet Rule”, so it loves to bond with lots of stuff to covalently share electron pairs.

Any chemical that consists of Carbon atoms joined to hydrogen atoms is categorized as being an Organic Molecule Sound Familiar? Carbohydrates Fats/Lipids Proteins DNA They are all important molecules found in and use by living things

Tap. 31b Here is a long Hydrocarbon Chain, each carbon is covalently bonded to more carbons and hydrogen atoms to satisfy the octet rule. This carbon is bound to two other carbons and two hydrogen atoms. So it shares 4 e- pairs which equals 8. Each carbon acts like it has 4 arms that are each searching for something to grab onto.

Tap. 31c Some hydrocarbon molecules will form rings to allow each carbon to satisfy its Octet Rule. If we check on any of the carbons it should be forming bonds with 4 other atoms

Tap. 31d Some key organic molecules found in the body are non-polar and do not mix with water. For example fats (like butter and oil). Any molecule that does not mix with water is described as being HYDROPHOBIC (“Water Fearing”) Other organic molecules found in the body are polar (having charged regions) and others are ionic (having an overall charge). For example, carbs, proteins and nucleic acids. These molecules dissolve easily in water, blood and tissue fluids. Because they mix well with water, they are described as being HYDROPHILIC (“Water Loving”)

Tap. 31e The Key organic chemicals on the left are very important to life forms. They are macromolecules (very large) polymers (many-unit molecules), but they are simply made by linking together much smaller single-unit (monomer) molecules.

Fig. 2.14

Fig. 2.15

Fig. 2.16

A carbohydrate lives up to its name, it is when you take a carbon atom and hydrate it (combine it with water H 2 O) C + H 2 O = CH 2 O ratio in its formula. Organic molecules that basically maintain the ratio of 1 C to 2 H to 1 O, are classified as being carbohydrates

Fig The most important simple carbohydrate used by the body is GLUCOSE. It is a monomer (single unit molecule) that is used by the body as a fuel for energy. You will never have to draw it, but you need to be able to recognize its molecular structure. In either three of its representations, see above.

Fig To build larger carbohydrates (polysaccharides/polymer) the organism will join many simple carbohydrates (monosaccharide monomers) together. Shown below is two Glucose molecules (monomers/monosaccharides) being joined to form one larger Maltose (disaccharide) molecule To perform this reaction a “H” comes off of one of the monomers and an “OH” off of the other. The H joins the OH to form a Water Molecule (H 2 O)

Fig Some Polysaccharides (carbs) you need to recognize – STARCH. Long straight chains of Glucose molecules. Formed in plants to store energy

Fig GLYCOGEN – formed in animal muscle and liver cells. Long branched chains of glucose molecules. Also used to store energy, but in animals

Fig CELLULOSE – Long straight chains of Glucose molecules, but every second glucose molecule is inverted. Note weird linkage. Not used for energy, but used as a complex carbohydrate in plants to build strong rigid cell walls for plant cells