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