Elements and Atoms
• Matter anything that has mass & takes up
• Atoms basic building blocks of matter.
• Elements basic substances that can’t be broken
into other substances.
• Molecules formed when 2 or more atoms bond.
• smallest unit of a cpd.
• Has the chemical & physical props. of the
• Compounds are made of atoms of different
elements chemically combined.
• Nucleus-center of an atom; includes protons and
• Cloud- surrounds nucleus; only electrons
• 3 subatomic particles:
Protons: positive charge
Neutrons: neutral/no charge
Electrons: negative charge
• 1st level holds 2 electrons
• 2nd level holds 8 electrons
• 3rd level holds 18 electrons
12 Atomic Number: Protons
Mg Atomic Symbol
Magnesium Name of Element
24.305 Atomic Mass Number: Protons
QUESTION: What part of the atom gives the atom its mass??
Not Containing Carbon
• Acids: substances that forms hydrogen (H)
hydrogen ions in water. pH of 0-7.
• Bases: substance that forms hydroxide
ions (OH) in water. pH scale of 7-14.
• Salts: Inorganic substances that often
contain Chlorine (but not always)
HCl H SO NaOH NaCl
2 4 KOH MgCl2
Exceptions: CO2 and H2O
So what is water??
A little bit A little bit
Acidic Basic = Neutral
Cells work on a
Four main types of
molecules a cell uses
• Nucleic Acids
Bio-molecule Made of:
Carbohydrates Simple sugars
Proteins Amino acids
Lipids Glycerol & at lease
1 fatty acid
Nucleic Acids Nucleotides (base,
Organic Substances – containsugar, phosphate)
Carbon and Hydrogen
Organic substances are made of units called
monomers or polymers.
Monomer- molecule that can bond to
form long chains.
Here is a monomer:
Polymer- a long chain of monomers
Here is a polymer:
Characteristics of Carbohydrates
Monomer Simple Sugar molecules
Function Stores energy and some structures
Examples Starch, glucose, fructose
Fact Usually large molecules
Food Bread, candy, pasta, vegetables
Video clips come from United
Streaming: Energy and the
Chemistry of Life (39:48)
Characteristics of Lipids
Monomer Fatty acids
Function Stores energy, forms membranes,
Examples Body fat, cell membranes, testosterone
Fact Lipids do not dissolve in water but do
dissolve in oils
Food Candy, red meats, fried foods, dairy
Characteristics of Proteins
Monomer amino acids
Function Makes enzymes (metabolism), forms
structures, some hormones
Examples Lactase, Insulin, hair, cartilage, muscle
Fact All proteins are made of the same 20
Food Meats, nuts, tofu
a) proteins used by a cell to
speed up and regulate metabolic
b) biological catalysts; are
unchanged by the reaction.
a) proteins with a 3-D shape.
b) shape determines the substrate for the
c) Substrates- substances that enzymes act
Lipase acts on lipids.
Maltase acts on maltose.
Protease acts on proteins.
Lactase works on Lactose .
3. How it works
a) substrate temporarily binds to enzyme active
b) enzyme may change shape to help substrate
4. Coenzymes - non-protein part of
a) If missing, the enzyme won’t
b) Vitamins may function as
5. The rate of enzyme activity
depends 5 things
o 3-D shape
o Activation Energy
6. Optimal temperature- temperature
at which enzyme works most
a) If temperature goes above or
below optimal temperature, rate of
enzyme action will decrease.
1. What is the optimal temperature for enzyme A? ________
2. What is the optimal temperature for enzyme B? ________
3. Knowing that room temperature is approximately 22 degrees Celsius,
which enzyme would work best in your body? __________
7. pH also affects
rate of enzyme
a) pH scale- a
hydronium ions in
b) Enzyme functions
best at optimum
1. The stomach has what optimal pH for that enzyme?
2. What is the optimal pH for the enzyme found in your intestine?
3. What organic substance are both of these enzymes digesting?
8. Concentration of the enzyme
affects rate of enzyme action
a) Greater concentration= faster
the rate of reaction; however,
b) optimal concentration of
enzyme gives the fastest rate
Characteristics of Nucleic Acids
Function Stores genetic information, directs cell
activity, makes proteins
Examples DNA and RNA
Fact DNA is a double helix and RNA is a
Food Most foods made from living materials
Place the item in the correct box.
Carbohydrates Proteins Lipids Nucleic Acids