Transcript Organic Molecules

Organic Molecules
CHAPTER 2 SECTION 3
Chemistry
 The study of the composition and properties of
substances as well as the changes they undergo
 2 different types of chemistry
1.
Organic
2.
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:
Carbon
Hydrogen
Oxygen
**Remember CHONPS**
Nitrogen
Phosphorus
Sulfur
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
Glucose
2. Galactose
3. Fructose
1.
All have same chemical formula C6H12O6
Q) So how can they have different properties?
A) They each have different structural formulas.
Disacharides
 Disaccharides are molecules that contain 2
monosaccharides
 3 different Disaccharides
1.
Sucrose = glucose + fructose
2.
Maltose = glucose + glucose
3.
Lactose = glucose + galactose
Polysaccharides
 Polysaccharides are very large molecules
composed of many monomers
 2 examples
1.
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!
Plant Cellulose
2.

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 water
Synthesis - 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 - water
Lysis - 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?
Act as Enzymes
1.

- special proteins that speed up chemical reactions
2. Aid in the transport of molecules
3. Help cells move (contraction of muscle)
4. Involved in the immune functioning (antibodies) to
fight disease
5. Act as hormones/receptors for signaling or
communication between cells
6. 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-units
1. 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
reactions
 How 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 > H2CO3
H2CO3 > 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 pathways
2.
Making materials that the cell needs
3.
Releasing energy
4.
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