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/LipidsProteins

DNAThey 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. 31eThe 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 H2O)

C + H2O = CH2O 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. 2.17

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. 2.18To 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 (H2O)

Fig. 2.19

Some Polysaccharides (carbs) you need to recognize – STARCH. Long straight chains of Glucose molecules.

Formed in plants to store

energy

Fig. 2.20GLYCOGEN – formed in animal muscle and liver cells. Long branched chains of glucose molecules.

Also used to store energy, but in animals

Fig. 2.21

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