Chapter 6 Lesson 1 Cells and Life

Chapter 6 Lesson 1 Cells and Life

• The basic units of all living things are cells.

• More than 300 years ago, an English scientist named Robert Hooke built a microscope.

• He used the microscope to look at cork, which is part of cork oak tree's bark.

• He called the structures cells, from the Latin word cellula, which means "small rooms."

Cell Theory:

• All living things are made of one or more cells.

• The cell is the smallest unit of life.

• All new cells come form preexiting cells.

Basic Cell Substances

• Macromolecules are substances in cells that are made of smaller parts that are joined together. (Like a train or chain)

• Macromolecules form by joining many small molecules together.

• Macromolecules cannot function without one of the most importnat substances in cells --- water.

• The main ingredient in any cell is water. It makes up more than 70% of a cell's volume and is essential for life.

• Water is not only in cells, but also surrounds cells. The water surrounding your cells helps to insulate your body, which maintain homestatis, or a stable internal environment

Macromolecules

There are four types of macromolecules in cells: nucleic acids, proteins, lipids, and carbohydrates.

Nuclei Acids

Macromolecules that form when long chains of molecules called nucleotides join together.

Nucleic acids are important in cells because they contain genetic information.

Proteins

Proteins are long chains of amino acid molecules.

The protein amylase in saliva, help break down nutrients in food. Other proteins, such as keratin ---- a protein found in hair, horns, and feathers--- provide structural support.

Lipids

A lipid is a large macromolecule that does not dissolve in water.

They play an important role as protective barriers in cells.

Examples of lipids are cholesterol, phospholipids, and vitamin A.

Carbohydrates

A macromolecule made up of one or more sugar molecules, which are composed of carbon, hydrogen, and oxygen; ususally the body's major source of energy.

Examples: breads, pasta

Cellulose is a carbohydrate in cell walls in plants that provides structural support.

Key Points

• The cell theory states that the cell is the basic unit of all living things.

• Water is the main ingredient in every cell.

• A nucleic acid, such as DNA contains the genetic information for a cell.

• Protein is a macromolecule made from amino acids.