Bellringer 9/24
•What
is
H2O?
1
2
UNIT 1 PART 3:CHEMICAL
COMPOUNDS OF LIFE
• The most common elements in living
things are:
– Carbon (C)
– Hydrogen (H)
– Oxygen (O)
– Nitrogen (N)
3
4
2 Types of Chemical Compounds
A. Inorganic compounds DO NOT contain
carbon and hydrogen,
Ex: O2, H2O, NaCl, CO2, HCl, H2SO4
Water is the most important inorganic compound.
B. Organic compounds contain both
carbon and hydrogen.
Ex: C6H12O6, NH2C4H8COOH, C17H35COOH
5
Organic Compounds
• Organic Compounds
always contain
Carbon and
Hydrogen.
• The 4 biologically
important types are:
– Carbohydrates
– Lipids
– Proteins
– Nucleic acids
Lipid
Protein
Carbohydrate
Nucleic Acid
6
Bellringer 9/25 2nd pd.
• Without looking at your
notes, list the 4 categories
of organic compounds we
learned about yesterday.
7
Bellringer 9/25 4th pd.
• Without looking at your
notes, list the 4 categories
of organic compounds we
learned about yesterday.
8
Carbohydrates: Sugars & Starches
Contain C, H & O
• The H’s & O’s are in a
2:1 ratio as in C6H12O6
• Usually end in –ose
• Usually have a 5 or 6
sided ring structure.
• Used for Energy
• Most common one is
glucose, C6H12O6.
9
Types of Carbohydrates
•Simple sugars, (glucose, fructose, ribose)
• Found in fruits, used as quick energy because they digest quickly
•Double sugars, (maltose, lactose, sucrose)
• 2 simple sugars combined to form one molecule. They are table
sugars, and also found in fruits and vegetables.
•Starches, (glycogen, cellulose-plant cell walls)
• String of many simple sugars combined in repeating chains They
are used as storage for large sources of energy and are found in
pastas, cereals, breads, vegetables
10
11
Dehydration synthesis
Dehydration synthesis is the joining of molecules with the
release of water (Dehydration) in a process that
forms a bigger molecule. (Synthesis = To make or build)
2 simple sugars into a double sugar
HO
OH
+
HO
OH
C6H12O6 + C6H12O6
HO

O
OH
+ H2O
C12H22O11 + H2O
12
Hydrolysis - Digestion
Hydrolysis – is the opposite of dehydration synthesis. This
is the breaking apart of complex molecules into simpler
ones, by adding water. This is part of digestion.
Changing starches back to simple sugars.
HO
HO
O
O
OH
+ 2H2O 
HO
OH
+
HO
C18H32O16 +
2H2O

OH
OH
3 C6H12O6
13
Lipids: fats, oils, and waxes
Contain C, H & O but not a 2:1 hydrogen and oxygen
ratio (H2O), they have many H’s & few O’s (C51H98O6)
The basic structure of the lipid is 3 fatty acids and a
glycerol molecule.
Glycerol
3 Fatty Acids
14
Lipids: fats, oils, and waxes
Lipids are used as long term energy sources because they
have about twice as much energy (calories) as carbohydrates.
They are used as part of membrane structures in cells.
Types of lipids:
1. oils- liquid at room temperature and come from
plants usually, ex: corn oil
2. fats- semisolid at room temperature, and come
from animals usually, ex: butter
3. waxes- solid at room temperature
4. steroids- hormones (chemical messengers)
They are also formed by dehydration synthesis.
15
Bellringer 9/28
•What does this (see
thing on desk)
represent? Name the
individual parts.
16
NUCLEIC ACIDS: DNA AND RNA
• Contain N and P as
well as C, H, and O
• Controls all cell
activities
• Building blocks are
nucleotides:
17
PROTEINS
Proteins always contain C,H,O, N and sometime S
a. Amino Acids are the building blocks of protein.
b. An amino acid is made of
1. a carboxyl group (acid) (COOH)
2. an amino group (NH2)
3. a side group, ( R )
c. The R group makes each amino acid different
Carboxyl group
Amino group
18
Common Amino Acids
19
Bellringer 9/29
• What is the building block of
–Proteins,
–Starches,
–Lipids, &
–Nucleic acids?
20
Dehydration synthesis of Proteins
• Dehydration synthesis combines many amino acids
together to form a protein molecule.
– The bond between amino acids is called a peptide bond
– A dipeptide contains 2 amino acids, a polypeptide, many
– Proteins are one or more polypeptides bonded together
21
SHAPE = FUNCTION
• Amino acids can be joined in
any order.
• Every sequence makes a
different protein.
• These chains can twist and
fold into many different
shapes.
• The sequence of amino acids
determines the shape of each
protein.
• The shape of the protein
determines its function.
22
Important Proteins
Proteins are used as:
1. Hormones - chemical
messengers
2. Antibodies - fight diseases
3. Receptor molecules –
cellular communication
4. Enzymes - control
chemical reactions in cell
23
Characteristics of Enzymes
•
•
•
•
Enzymes are Specific (do 1 reaction).
Enzymes help reactions to occur Faster
Enzymes are used over and over
Enzymes are not changed by reactions
24
Characteristics of Enzymes
•
•
•
•
Enzyme reactions are reversible.
Enzyme names end in –ase. (protease,
lipase)
Enzymes are helped by coenzymes
(vitamins).
Enzymes are affected by temperature,
pH, & concentration.
25
Lock and Key Theory
Each chemical reaction requires a specific
enzyme, shaped in a specific way.
The substrate is the substance acted
upon by the enzyme.
The enzyme molecule joins temporarily
with the substrate (forming an enzymesubstrate complex)
The enzyme helps a reaction to take
place in the substrate.
Upon completion of the reaction, the
enzyme releases the new products.
26
Lock & Key Theory
Substrate
Products
EnzymeSubstrate
Complex
Enzyme
Enzyme
27
Effect of temperature on enzymes
• Every enzyme works best at a specific
temperature (called optimum
temperature).
• An enzyme is denatured at high
temperatures (loses its shape) and will
not work
• At low temperatures the enzyme lacks
the energy to work, but its shape is not
denatured.
28
Effects of pH on enzymes
• Enzymes work best at a specific pH
level.
– Stomach enzymes work best at low pH 2
levels.
– In your intestine, enzymes work at pH 8.
• Outside of the optimum pH the
enzyme is denatured, (loses its
shape) and will not work
29
Effect of Concentration on
Enzyme Action
• If the amount of
enzyme remains
constant and you
add substrate, the
rate of reaction will
increase.
• Eventually all of the
enzyme is being used
so the reaction rate
will level off.
• If the amount of
substrate remains
constant and you
add enzyme, the
rate of reaction will
increase.
• Eventually all of the
substrate is being
used so the reaction
rate will level off.
30
31
Key to ID Organic Compounds
1a: Has both C and H’s…………….……..…....…Goto 2
1b: Does not have both C and H’s………….…Inorganic
2a: Has N in it…………………..……………..Goto 3
2b: No N in it………..….……………………..Goto 4
3a: Has P in it…….………………......Nucleic acid
3b: No P in it………………………....….…Protein
4a: H’s and O’s in a 2:1 ratio…….Carbohydrate
4b: No 2:1 ratio………………...…………Lipid
32