Chapter 2
Biochemistry
The Chemistry of Life
pH
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Measure of acidity (acid) or alkalinity (basic)
Scale
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Acid– b/w 1-6.9
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Ex: stomach acid, urine, lemon juice
Base– b/w 7.1-14
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0-14
“alkaline” refers to a base
Ex: intestinal fluid, blood
Neutral - 7

Look at pH scale pg.44
Dissociation

The process by which compounds break apart
when they are “dissolved” in water
CHEMICAL SUBSTANCES THAT
NEUTRALIZE SMALL
AMOUNTS OF EITHER ACIDS OR BASES

Buffers
Buffers Cont

Needed to maintain a pH of 7 (neutral)
What characteristic of life would maintaining
this balance be? _________________

***Basic or acidic solutions denature proteins
(changes their shape) -- make it where they can’t
work****
OCCURS WHEN AN ACID IS
COMBINED TO THE SAME AMOUNT OF A BASE
 RESULTS IN THE PRODUCTION OF
SALT + WATER

Neutralization
********************************************
Atoms and Their Interactions
Elements
•Substances
that cannot be broken
down into simpler substances
•Found on the periodic table
Elements

25 are essential to living organisms
C, H, O, N
 90% of human mass
 Remember “CHNOPS”

the smallest particles of
an element that has the
characterisitics of that
element
atom
Living organisms

Made of atoms– found inside cells
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Put 2 or more atoms together you get elements
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Protons
Electrons
Neutrons
109 elements total
Ex: O2, O3
2 or more elements together you get a compound
Ex: H2O, C6H12O6
 ++++++++++++++++++++++++++++++++++++++++++++++++
QSR #4

1. Give the symbols for the following elements:
Carbon____
 Hydrogen____
 Sulfur____
 Nitrogen____
 Phosphorus____


2. What is the chemical formula for water?____
Carbon dioxide?______ oxygen?_______
Carbon monoxide?______ glucose?_______
All of the chemical
reactions that occur
within an organism are
referred to as
Metabolism
Chemical equations
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Reactants
Products
Subscripts
Ex: Photosynthesis and respiration equations

Write in your notes and memorize!!!
solution
Solvent
– present in the greatest
amount, and dissolves other
substances
Solute – dissolves in the solvent
Ex: Kool-aid?
Ex: atmosphere?
Solutions contTHE AMOUNT OF SOLUTE
DISSOLVED IN A SOLVENT

CONCENTRATION
(The higher the solute the higher the
concentration)
Ex: urine, salt water, orange juice

The opposite of very concentrated –
higher solvent concentration
diluted

A SOLUTION IN WHICH NO MORE
SOLUTES CAN DISSOLVE
Saturated Solution
+++++++++++++++++++++++++++++
Carbon Compounds

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Organic Molecules– molecules that contain
mostly Carbon (C) and Hydrogen (H)
3 Structures of Carbon:
Straight chains
 Branched chains
 Rings

Straight Chain
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H H H H H H H
| | | | | | |
H -C- C- C-C- C- C- C - H
| | | | | | |
H H HHH HH
Carbon needs 4 bonds to be stable!!!
Branched Chain
Carbon Ring
C
C
C
C
C
C
QSR #4
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1. Draw a simplified view of a carbon ring.
2. All compounds are either organic or
inorganic. Organic means they contain primarily
___ atoms.
3. Carbon needs ___ electrons to be stable.
4. Draw C4H10 as a straight chain and a
branched chain and C4H8 as a ring.
Biochemistry

Review: Most common elements in living things
are?

C, H, O, & N = 90% of your body mass
Compounds

Macromolecules

Large molecules

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Proteins, lipids, carbohydrates, & nucleic acids
Made of subunits called monomers
Ex: Starch is a polymer of what monomer?
QSR #10
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1. Vinegar has a pH of 3 which means its an
________ while detergent has a pH of 11
making it a strong __________.
2. Which is the stronger base…11 or 14? ____
3. Unbalanced pH levels can be harmful to
cells, thus _________ in your blood help to
maintain a balanced pH.
4. Other than balancing pH levels, what’s one
more example of homeostasis?
Biochemistry

Review: Most common elements in living things
are?

C, H, O, & N = 90% of your body mass
Building Blocks of Cells
4 Main classes of organic compounds:
ORGANIC = CONTAINS CARBON (C)
Carbohydrates
 Lipids (fats)
 Proteins
 Nucleic Acids

Carbs
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Made of C,H,O
Include:
Fruits
 Veggies
 starches

Carbohydrates (also called
polysaccharides)
2 JOBS:
 1. provide the body with SHORT
TERM energy


Like sugars and starches
2. Provide structural support in cell
walls

Ex: Cellulose – we can’t digest (don’t
have enzymes for it)
Carbohydrates
3 types:
 1. Monosaccharides – simple sugars
Found in sugars that come from plants ex: fruit
 1 sugar
 Ex: Glucose & fructose – natural sugars found in
fruits
 EASIEST TO BREAK DOWN FOR ENERGY –
but it doesn’t last long at all
 “sugar high”

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2. Dissacharides – (2 monosaccharides)
2 sugars – still easy to break down
 Provides energy for a little longer
 Ex: Sucrose/table sugar – candy, sweet tea
 Ex: Lactose – milk sugar – milk, yogurt
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3. Polysaccharides – “Complex carbs”
**these are your STARCHES
 Many sugars (made of more than one sugar)
 HARDEST TO BREAK DOWN – thus it provides
energy the longest
 Ex: Starch– long chain of sugars
 food storage by plants (roots)
 Ex: potatoes and rice
Glucose -- simple sugar
Fructose – also a simple sugar
Glucose + Fructose = Sucrose
QSR #11
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1. Monosaccharides are made of only ___ sugar
and are found in _________ and veggies…not
_________ sugar.
2. Carbs consist of 3 elements: ___, ____, ____
3. The main function of carbs is to provide
_________ for our cells, with ______________
providing us with the most energy.
4. Sucrose, or “_______ sugar”, is made of 2
monosaccharides (________ and fructose), thus
sucrose and ________ are disaccharides.
Lipids
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Do not dissolve in water
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nonpolar
2 types
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Saturated – solid at room temp
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Unsaturated – liquid at room temp
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Ex: meats and cheeses
Ex: olive oil
Includes fats, phospholipids,
waxes, and oils
Calories

Calories
1g of fat = 9 calories
 1g of carbs = 4 calories

Types of lipids
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A. Phospholipids – provide support for cell
membranes
B. Cholesterol – also found in cell membranes
Lipids

Monomers are fatty acids:
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Fats/oils–
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Long chains of C-H bonds with a glycerol end
Plant fats: olive oil and peanut oil
Animal fats: butter and meat
Used for
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Energy storage
Insulation
Protective covering
SATURATED
SATURATED
UNSATURATED
Proteins
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Made of subunits called amino acids (which are
used to build cells)
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20 different amino acids– your body can make 12, so
where do the others come from?
Made of C,H,O,N and sometimes S
Ex: Hair and horns are made mostly of protein
What are some foods high in protein?
Proteins
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Amino acids are held together by Peptide Bonds
Thus AA’s often form long chains called
Polypeptides
Proteins are often large molecules consisting of
hundreds of AA’s
Macromolecules and Monomers

Last slide
Monomer
Example of a Macromolecule
polysaccharide (complex carbohydrate) monosaccharide (simple sugar)
fat (a lipid)
glycerol, fatty acid
protein
amino acid
nucleic acid
nucleotide
A protein that changes
the rate of a chemical
reaction
Enzyme
Enzymes
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Catalyst that Speed up the digestion of food
and other chemical reactions
Act like a lock and key mechanism
Substrate: specific reactants that an enzyme acts
on

Ex: Amylase is an enzyme (found in saliva) that
recognizes the substrate Starch – thus initiating the
break down of starch
Enzymes

Factors that change the shape of enzymes (i.e.
proteins) – affecting their function to control
chemical reactions in your body:
1. High temperatures
 2. Unbalanced pH levels
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QSR #8
1. Proteins are made of subunits called ______
_________.
2. They also act as _______ helping control the speed
of digestion.
3. Enzymes work specifically to fit certain ________(s)
in a lock and key type mechanism.
4. What are 2 things that can alter the shape and
effectiveness of enzymes?
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A.
B.
5. Amylase is the _______ and starch is the ________.
6. The substrate attaches to an enzyme at its _______
________
Nucleic Acids

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Stores cellular/hereditary information
Made of monomers called nucleotides

ATP – Adenosine Triphosphate – has the structure
of a nucleotide, just with 3 phosphate groups

ATP is a compound that supplies energy to your cells
Nucleic Acids

2 kinds

DNA
Deoxyribonucleic acid
 Double stranded
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RNA
Ribonucleic acid
 Single stranded

Structure of nucleotides

Contain 3 parts:
1. a phosphate group (unless its ATP, then it has 3
phosphate groups)
 2. a pentose sugar ( 5-C sugar)
 3. Nitrogen base

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Several of these nucleotides linked together make
DNA and RNA strands
Outline for Test
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1. pH (acids, bases, neutral, buffers, etc.)
2. Atoms, elements, and compounds
3. Solutions
Solutes vs solvent
 Concentrated vs diluted
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4. The 4 Organic compounds (macromolecules)
Carbohydrates
 Lipids
 Proteins
 Nucleic acids

Section Assessment pg. 167
List 3 important functions of lipids in living
organisms.
Long-term energy storage, insulation, and protective
coatings
2.
Describe the process by which polymers in living
things are formed from smaller molecules.
Polymers form when one monomer loses an H+ ion
and another loses an OH- to form water. A
covalent bond forms between the monomers.
1.
How does a monosaccharide differ from a
disaccharide?
A disaccharide is made of two simple sugars
called monosaccharides.
4. Enzymes are proteins that facilitate chemical
reactions. Based on your knowledge of
enzymes, what might the result be if one
particular enzyme malfunction or was not
present.
The chemical reaction would proceed extremely
slowly.
3.
5. Make a table comparing polysaccharides,
lipids, proteins, and nucleic acids. List these 4
types of biological substances in the first
column. In the next two columns, list the
subunits that make each substance and
functions of each in organisms. In the last
column, provide some examples of each from
the chapter.
Molecules
Subunits
Functions
Polysaccharide Monosacchari For energy
s
des
storage and
structural
components
Lipids
Fatty Acids
Long-term
and Glycerol energy storage
Proteins
Amino Acids
Examples
Starch,
glycogen, and
cellulose
Animal fats
and vegetable
oils
Structure and Muscle,
enzymes
immunity
proteins,
enzymes
6.1 Atoms and Their Interactions
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Atoms are the basic building blocks of all matter.
Atoms consist of a nucleus contain protons and
neutrons. The positively charged nucleus is surrounded
by a cloud of rapidly moving, negatively charged
electrons.
Atoms become stable by bonding to other atoms
through covalent or ionic bonds.
Components of mixtures retain their properties--components of solutions do not.
6.1 Vocabulary
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Acid
Atom
Base
Compound
Covalent bond
Element
ion
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Ionic bond
Isotope
Metabolism
Mixture
Molecule
Nucleus
pH
solution
6.3 Life Substances
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All organic compounds contain carbon atoms.
There are 4 principal types of organic
compounds that make up living things:
carbohydrates, lipids, proteins, and nucleic acids.
Vocabulary
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Amino acid
Carbohydrate
Enzyme
Isomer
Lipid
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Nucleic acid
Nucleotide
Peptide bond
Polymer
protein
Understanding Main Ideas
1.
2.
What are the basic building blocks of all
matter?
c. Atoms
Which feature of water explains why water has
high surface tension?
c. Water is a polar molecule
3.
Which of the following describes an isotope of the
commonly occurring oxygen atom which has 8 protons,
and 8 neutrons?
a. 8 electrons, 8 protons, and 9 neutrons
4.
Which of the following will form a solution?
c. Salt and water
5.
Which of the following applies to a water molecule?
d. Water molecules have a negatively charged
end and positively charged end
Which of the following carbohydrates is a
polysaccharide?
d. Starch
7. Which of the following pairs is unrelated?
d. Starch—nucleic acid
8. An acid is any substance that forms
c. Hydrogen ions
9. Which of these is NOT made up of proteins?
d. cellulose
6.
10.
11.
12.
Which of the following is NOT a smaller
subunit of a nucleotide?
d. Glycerol
An enzyme ____ chemical reactions
speeds
A calcium atoms has 20 protons and ___
electrons
20
13.
A ____ bond involves sharing of electrons.
covalent
14.
The first energy level of an atoms holds ___ electrons;
the second energy level holds 8 electrons.
2
15. In a water molecule, each ____ atom shares one electron
with the single ___ atom.
hydrogen; oxygen
16.
A substrate fits into an area of an enzyme called the
active site
17.
Hydrogen, chlorine, and sodium are examples of
Elements
18.
Long chains of amino acids connected to each
other by a ___ bond form a ____.
peptide; protein
19.
Diffusion is the process in which molecules
move from ___ concentration to a ____
concentration.
high; low
20.
The positively charged ___ atoms of one water molecule
attract the negatively charged ____ atom of another water
molecule.
hydrogen; oxygen
21.
Magnesium atom has 12 electrons. When it reacts, it
usually loses two electrons. How does this loss make
magnesium more stable?
The underlying energy level is a filled layer.
22.
Explain why water and a sponge would not be
effective in cleaning up a grease spill.
Water is a polar molecule; it will not
attract the nonpolar grease.
23.
Explain why carbon is the most critical
element to living things.
Carbon is the building block element
of the 4 basic substances
(carbohydrates, lipids, proteins, and
nucleic acids) found in all known
living organisms.
24.
If heating a white substance produces a
vapor and black material, how do you
know the substance was not an element.
The substance was a compound
because 2 new substances were formed
by the chemical reaction.