CHAPTER 2 SECTION 3

Organic Molecules

Chemistry

The study of the composition and properties of substances as well as the changes they undergo

2 different types of chemistry1. Organic2. Inorganic

Inorganic Chemistry

The study of all compounds that DO NOT CONTAIN CARBON, except for the oxides of carbon and carbonates

Example) CO2 – carbon dioxide

Organic Chemistry

Study of organic compounds, or those that CONTAIN CARBON

Can be further subdivided into Biochemistry Primarily concerned with organic chemistry and the

structure and reactions of carbohydrates, lipids, nucleic acids, and proteins as well as inorganic compounds such as water and carbon dioxide

Deals with molecules that make up the body

Chemistry Information

Out of the 117 naturally occurring elements, only 11 are found in living things and another 20 are found in “trace amounts”

6 of the most abundant elements in living things are:

CarbonHydrogenOxygenNitrogenPhosphorusSulfur

**Remember CHONPS**

Why is carbon so special?

All compounds are classified on whether they contain carbon or not…

Reason #1 Carbons amazing ability to form covalent bonds Carbon’s atomic # is 6… how many more electrons

does it need to be happy?

Reason #2 Carbon can form chains of unlimited length by

bonding to other carbon atoms

Figure 2-11 Pg 44

Macromolecules

Macro – large/big

Macromolecules – very large polymers

How do they form? Polymerization – pieces called monomers are put

together to form polymers Examples)

Puzzels 26 letters in alphabet (monomers) make tons of words

(polymers)

Figure 2-12 Pg 45

4 Groups of Organic Molecules

1. Carbohydrates

2. Lipids

3. Nucleic Acids

4. Proteins

Carbohydrates

Composed of C, H, O atoms in a ratio of 1:2:1 example C6H12O6 > 6 : 12 : 6 reduced in 1 : 2 : 1

Primary fuel source for metabolism main source of energy and used for structural

purposes in the cell

Carbohydrates Cont.

Complex carbohydrates are called “starches” Which are polymers

Monomers are individual sugar molecules

- so-

Single sugar molecules are called Monosaccharides

3 Different Monosaccharides

1. Glucose2. Galactose3. Fructose

Q) So how can they have different properties?A) They each have different structural

formulas.

All have same chemical formula C6H12O6

Disacharides

Disaccharides are molecules that contain 2 monosaccharides

3 different Disaccharides1. Sucrose = glucose + fructose2. Maltose = glucose + glucose3. Lactose = glucose + galactose

Polysaccharides

Polysaccharides are very large molecules composed of many monomers

2 examples1. Glycogen (animal starch)

When glucose levels run low in your blood, glycogen is released from your liver… Glycogen stored in your muscle supplies the energy needed for muscle contraction… movement!

2. Plant Cellulose Tough flexible cellulose fibers give plants much of their

rigidity and strength… major component of wood and paper

Which is Which?

Where is a monosaccharide?

Where is a disaccharide?

Where is a polysaccharide?

Building Up and Breaking Down

You need 2 processes to build or break down molecules…

How do you make (build up) a Disaccharide?

Dehydration Synthesis – the process by which a water molecule is lost when 2 or more monosaccharides are combined

Dehydration - to lose waterSynthesis - to make

Dehydration Synthesis

GLUCOSE + FRUCTOSE → SUCROSE + WATER

Breaking Down Molecules

How do you break down a Disaccharide?

Hydrolysis - the process by which a disaccharide or polysaccharide is broken apart by the addition of water

Hydro - waterLysis - to break

Hydrolysis

MALTOSE + WATER → GLUCOSE + GLUCOSE

Hydrolysis

MALTOSE + WATER → GLUCOSE + GLUCOSE

Glucose

Glucose

+

Lipids

What are Lipids?

Commonly know as fats, oils and waxes

Composed of Carbon, Hydrogen (and Oxygen) atoms

Ratio of Hydrogen to Oxygen atoms is greater than 2:1.

What are lipids good for?

3 Main purposes of lipids in the body

1.Store energy

2.Special lipids called phospholipids form the cell membranes of your approximately 80 trillion cells

3.Act as chemical messengers for the cell

What does a lipid look like?

GLYCEROL + 3 FATTY ACIDS = 1 LIPID (triglyceride)

Types of lipids

Saturated Fats:Found in meats and dairy products

Every carbon atom in a fatty acid chain is joined to another carbon by a single bond

Tails packed together!

Saturated with Hydrogen

Another type of Lipid

Unsaturated Fats:When carbons are joined by double bonds

Tails cannot pack together as tightly

Do not contain the maximum number of hydrogen atoms Double bonds form kinks in the chain and KINKY

IS GOOD! Makes it easier for the body to break molecules

down.

Saturated vs Unsaturated Fats

REMEMBER… KINKY IS

HEALTHY!!!

How do you make a Lipid?

Answer: DEHYDRATION SYNTHESIS Process by which water molecules are lost when

monomers (glycerol and fatty acids) are joined

1 GLYCEROL + 3 FATTY ACIDS > LIPID (triglyceride) + 3 water

How do you break down a Lipid???

Answer: HYDROLYSIS Process by which a lipid is broken down by the

addition of 3 water molecules

LIPID (triglyceride) + 3 water > 1 GLYCEROL + 3 FATTY ACIDS

Proteins

What are Proteins?

Organic macromolecules

Composed of Carbon, Hydrogen, Oxygen, and Nitrogen

DNA is the recipe for making proteins in your body

What are proteins good for?

1. Act as Enzymes - special proteins that speed up chemical reactions

2. Aid in the transport of molecules3. Help cells move (contraction of muscle)4. Involved in the immune functioning

(antibodies) to fight disease5. Act as hormones/receptors for signaling or

communication between cells6. Give the cell structure and support (form

the cytoskeleton of all your 80 trillion cells)

What does a protein look like?

AMINO ACID + AMINO ACID > PROTEIN (DIPEPTIDE)

So what are amino acids?Functional groups of proteins

What is an amino acid?

Functional group of a protein that contains:1. Amino Group (-NH2)

2. Carboxyl Group (-COOH)

3. R-Group **this makes each of the 20 amino acids different )

Amino Acid General Structure

How do you make a protein?

Answer: DEHYDRATION SYNTHESIS Process by which a water molecule is lost when

monomers (2 amino acids) are joined

AMINO ACID + AMINO ACID > PROTEIN (DIPEPTIDE)

How do you break down a protein?

Answer: HYDROLYSIS Process by which a protein is broken down by the

addition of a water molecule

PROTEIN (DIPEPTIDE) > AMINO ACID + AMINO ACID

What are Nucleic Acids?

Organic macromolecules

Consists of Carbon, Hydrogen, Oxygen, Nitrogen and Phosphorus

2 kinds: Ribonucleic Acid (RNA) Deoxyribonucleic Acid (DNA)

Polymers of nucleotides

What is a Nucleotide?

Functional unit of a Nucleic Acid

Consists of 3 sub-units1. 5-Carbon Sugar

(ribose for RNA and deoxyribose for DNA)

2. Nitrogenous Base

3. Phosphate Group

What are Nucleic Acids good for?

Store and transmit genetic information

RECIPE FOR MAKING PROTEINS Because each person has a different recipe, each

person is different

Chemical Reactions and Enzymes

Key Concepts:What happens to chemical bonds during chemical

reactionsHow do energy changes affect whether a

chemical reaction will occur?Why are enzymes important to living things?Chemistry isn’t just what life is made of… it’s

also what life does.Everything that happens in an organism > it’s

growth, interaction with the environment, reproduction and movement is based on chemical reactions.

Chemical Reactions

Chemical reaction Process that transforms or changes, one set of chemicals

into another

Reactants Compounds or elements that enter a chemical reaction

Products Compounds or elements produced by a chemical reaction

REACTANT + REACTANT > PRODUCT(monosaccharide + monosaccharide > disaccharide)

Chemical Reactions

*chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in

products*

Example:CO2 + H2O > H2CO3H2CO3 > CO2 + H2O

Cells produce CO2 and need to remove it. (carried through blood to lungs where it’s exhaled)

CO2 enters blood and reacts with H2O to produce highly soluble compound carbonic acid (gets to lungs)

In lungs, reaction is reversed, CO2 released as you exhale

Energy in Reactions

Energy is released or absorbed whenever chemical bonds form or are broken. Because chemical reactions involve breaking and forming bonds, they involve changes in energy.

Changes in Energy

Some chemical reactions that release energy often occur spontaneously

Chemical reactions that absorb energy will not occur without a source of energy

Activation Energy – the energy needed to get a reaction started

Energy Changes

*important factor in determining whether the overall chemical reaction releases or absorbs energy.

(see figure 2-19 on page 50)

Enzymes

Play essential roles in 1. Regulating chemical pathways2. Making materials that the cell needs3. Releasing energy4. Transferring information for the cell

Special proteins in the body that speed up a reaction.

Enzymes

Enzymes are called biological catalysts. Why?

Catalysts work by lowering the activation energy. See figure 2.20 on page 51

CO2 + H2O > H2CO3

Carbonic Anhydrase

Enzymes

Enzymes are very “SPECIFIC”. What does the property of specificity mean?

Enzyme’s name is usually derived from the reaction it catalyzed (-ase ending)

Example) Lactose is broken down into glucose and galactose by

lactase Maltose is broken down into glucose and glucose by

maltase

How do Enzymes do their Job?

For a chemical reaction to take place, the reactants must collide with enough energy so that the existing bonds with be broken and new bonds will form.

Enzymes provide a site where reactants can be brought together to react and reduces the amount of energy needed for the reaction.

The Enzyme-Substrate Complex > the “Lock and Key Method”

Enzymes work best at “optimal temperatures” and pH values.

Lock and Key Method

Draw your own picture…

Analyzing Data