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3-3 Chemical Compounds in Cells
I.
Elements and Compound
A. Elements
1. Elements- any substance that cannot be broken down into simpler
substances.
2. The smallest unit of an element is called an atom.
3. An element is only made up of one atom.
B. Compounds
1. Compounds- when two or more elements are combine chemically.
2. The smallest unit of many compounds is a molecule.
C. The Compound Called Water
1. Most chemical reactions within cells could not take place without water.
2. Water makes up about 2/3 of your body.
3. Without water plants would not be able to convert energy captured
from chloroplasts into food.
D. Inorganic and Organic Compounds
1. Inorganic compound does not contain the element carbon.
2. Most compounds that contain carbon are called organic compounds.
3. Carbohydrates, lipids, proteins, and nucleic acids are important groups
of organic compounds in living things.
Il. Carbohydrates
1. Carbohydrate-is an energy-rich organic compound made of elements
carbon, hydrogen, and oxygen.
2. In addition to providing energy for the cell, carbohydrates are important
components of some cell parts.
II.
Lipids
1. Lipids- are energy rich organic compounds made of carbon,
hydrogen, and oxygen.
2. Lipids contain more energy than carbohydrates.
3. In addition to their function as an energy source, lipids also make up
most of the cell membrane.
III.
IV.
Proteins
1. Proteins- are large organic molecules made of carbon, hydrogen,
oxygen, nitrogen and in some cases sulfur.
A. Structure of Proteins
1. Protein molecules are made up of smaller molecules called amino
acids.
2. There are 20 common amino acids that combine in different ways
to form thousands of different proteins.
B. Functions of Proteins
1. Much of the structure of the cell is made up of proteins.
2. The proteins known as enzymes perform important functions in
the chemical reactions that take place in cells.
3. Enzyme- a type of protein that speeds up a chemical reaction in
living things.
4. Without enzymes, many chemical reactions that are necessary for
life would either take too long or not occur at all.
Nucleic Acids
1. Nucleic Acids- very long organic molecules made of carbon, oxygen,
hydrogen, nitrogen, and phosphorus.
2. Nucleic Acids contain the instructions that cells need to carry out all
the functions of life.
3. There are two kinds of nucleic acids:
a. Deoxyribonucleic Acid (DNA)-the genetic material that carries
information about an organism and is passed from parent to
offspring. Most of the DNA in a cell is found in the chromatin in
the nucleus.
b. Ribonucleic Acid (RNA)- plays an important role in the production
of proteins. Found in the cytoplasm as well as in the nucleus.