Organic Molecules• Carbon = building block of

organic molecules• Carbon is unique

– Unstable: 2nd level not full– Will bond up to four times

1

2

3

4

1

2

6 protons6 electrons

Organic Molecules• Carbon = building block of

organic molecules• Carbon is unique

– Unstable: 2nd level not full– Will bond up to four times

• Monomer: Small carbon molecules– Ex: Amino acid

• Polymer: chain of linked monomers– Ex: Protein

monomer

monomer

monomer

monomer

monomer

monomer

monomer

monomer

monomer

monomer

Polymer

Is Carbon stable with 4 electrons in its outer layer?

Is Hydrogen stable with 1 electron in its layer?

So what do atoms do when they are unstable?

Problem: Drawing dot diagrams is time consuming. Try this instead!

1 dash = 2 electrons

The Same Thing…

1 dash = 2 electrons

Carbon creates 4 bonds to be stable

Double bonds

Triple bonds

Ring structures

Single bonds

Very complex

How many electrons? How many

electrons?

How many electrons?

How many electrons?

How many electrons?

1 Dash = 2 electrons

Carbohydrates• Readily available food source• C1: H2: O1 ratio

– Ex: Glucose = C6 H12 O6

• Monomer: Monosaccharides– Simple sugars– Bond to form larger sugars

• Polymer: Polysaccharide– Complex sugars

Glucose(monosaccharide)

Fructose(monosaccharide)

Sucrose

(Polysaccharide)

Opposite Reactions

• Dehydration synthesis– Water molecule (H2O) removed– Causes monomers to bond into polymers (large molecules built)

Monomer 1 Monomer 2 Polysaccharide

water

Opposite Reactions

• Dehydration synthesis– Water molecule (H2O) removed– Causes monomers to bond into polymers (large molecules built)

• Hydrolysis– Water molecule (H2O) added– Causes polymers to break into monomers (large molecule broken

apart)• All organic molecules built/reduced by these reactions

Polysaccharide Water Monomer 1 Monomer 2

Opposite Reactions

Carbohydrate Polymers: Polysaccharide

• Polysaccharides: Long chain of monosaccharides• Ex: Starch: excess plant sugar converted & stored• Ex: Glycogen: animal starch stored in liver & muscles• Ex: Cellulose: used in plants to make cell walls

glucose glucose glucose glucose

glucose

Chapter 2 Free Response Test Question

Version A: Diagram the process of hydrolysis using a sugar as an example. Be sure to indicate the following:

a. Original moleculesb. End moleculesc. Label all parts, including the bond atoms

Version B: Diagram the process of dehydration synthesis using a sugar as an example. Be sure to indicate the following:

a. Original moleculesb. End moleculesc. Label all parts, including the bond atoms

Kobe Kuiz1) How many electrons does Carbon have in the 1st energy

level? 2nd energy level?2) Which type of organic molecule is most commonly used

as energy for cells?3) If a carbohydrate has 8 carbon atoms, how many oxygen

and hydrogen atoms will it most likely contain?4) What are the monomers of carbohydrates called?5) What are the polymers of carbohydrates called?6) How does dehydration and hydrolysis differ?7) Which polymer is stored by animals?8) Which polymer is stored by plants?