Chemical Compounds
in Cells
Lesson 2
Energy Backpacks
Some people think a camel’s humps carry
water. NOT true! They actually store fat. A
hump’s fatty tissue supplies energy when
the camel doesn’t eat. When a camel has
enough food, the hump remains hard and
round. But when food is limited, the hump
gets smaller and may fall to the side. If the
camel then gets more food, the hump can
regain its full size and shape in about three
of four months.
Energy Backpacks
Discuss the following questions and
answer.
 How do you think having humps has
helped camels survive?
 How do you think the camel might be
affected if it didn't have humps?
 What foods do you eat for energy?
 What foods do you think you SHOULD eat
for energy?
What are Elements and Compounds?
We are made up of many substances, called
Elements.
Element: Any substance that cannot be
broken down into simpler substances.
Elements found in the body:
Carbon (C); Hydrogen (H); Oxygen (O);
Nitrogen (N)
**sometimes Phosphorus (P); Sulfur (S)
What are Elements and Compounds?
Atom: The smallest unit of an element.
Any single element is made up of only one kind of atom.
Ex. The element Oxygen (O) is ONLY made up of Oxygen
atoms!! The element Hydrogen (H) is ONLY made up of
Hydrogen atoms!! The element Carbon (C) is ONLY made
up of Carbon atoms!!
**Is Water H2O an element?...
What are Elements and Compounds?
NO…Water is not an element… it is a compound.
Compound: Forms when two or more elements combine
chemically.
Hydrogen (H)-- Element
Oxygen (O) -- Element
H2O – Compound
Water has two elements combined chemically.
Carbon (C) – Element
Oxygen (O) – Element
CO2 – Compound
Carbon dioxide has two elements combined chemically.
What Compounds Do Cells Need?
 Every cell must either make or absorb some
compounds to survive.
 Many of the compounds in living things contain the
element Carbon (C).
Organic Compounds: Compounds that contain Carbon
(C).
Necessary Organic Compounds for cells: Carbohydrates,
Lipids, Proteins and Nucleic Acids.
What Compounds Do Cells Need?
Inorganic Compounds: Compounds that do not contain
carbon.
Ex. Water and Table Salt
Carbohydrates: Energy-rich organic compounds made of the
elements carbon, hydrogen and oxygen.
Ex. Pasta, Potatoes, Rice, Bread, Fruit, Milk, Candy
 When you break down foods that contain carbohydrates
starches that are in these foods turn into sugar that your
cells use to get energy.
What Compounds Do Cells Need?
Lipids: Compounds that are made mostly of
carbon, and hydrogen and some oxygen.
Ex. Fats, Oils, Waxes, (whole milk, ice
cream)
 Fats and oils contain more energy than
carbohydrates. Cells store energy from
fats and oils for later use.
What Compounds Do Cells Need?
Proteins: Large organic molecules made of carbon,
hydrogen, oxygen, nitrogen, and sometimes sulfur.
Ex. Meat, Dairy products, Fish, Nuts, Beans
 Most of a cell’s structure and function depends on
proteins. Proteins form part of a cell’s membrane and
make up parts of the organelles within a cell.
Enzymes: A group of proteins that speed up chemical
reactions in living things.
** Without enzymes all the chemical reactions that are
necessary for life would take a REALLY long time**
Ex. We have enzymes in our saliva which speeds up
digestion!
What Compounds Do Cells Need?
Nucleic Acids: Very long organic molecules.
These molecules consist of: Carbon, Oxygen, Hydrogen,
Nitrogen and Phosphorus.
Nucleic Acids contain the instructions that cells need to
carry out all the functions of life.
Foods high in nucleic acids: Red meat, Shellfish,
Mushrooms, Peas
DNA is an example of a nucleic acid.
What Compounds Do Cells Need?
DNA (Deoxyribonucleic acid): Genetic material that
carries information about an organism and is passed
from parent to offspring.
 Chromatin is made of long strands of DNA wrapped
around proteins.
 Directs a cell’s function
 Found in a cell’s nucleus
 DNA shape: Double Helix
Water and Living Things
Two thirds of the human body is WATER!
 Most chemical reactions in cells depend on
substances that MUST BE dissolved in water to react.
 Helps cells keep their shape.
 Helps keep the temperature of cells from changing
rapidly. (water’s temp. changes slowly)
 Water plays a key role in carrying substances into
and out of cells.