The Chemistry of Life

What Are Cells Made Of? All living things are made of cells, but what are cells made of? There are five common compounds found in all cells: proteins carbohydrates lipids nucleic acids ATP

Proteins Almost all life processes of a cell involve proteins. Protein is a biochemical made up subunits called amino acids, which are the building blocks of proteins. Organisms break down proteins in food to supply their cells with amino acids. Amino acids then link together to form new proteins.

Functions of Proteins Proteins regulate chemical reactions, transport and store materials, protect cells from foreign materials, and provide support for the body. Hemoglobin is a protein in red blood cells that attaches to oxygen so that oxygen can be delivered throughout the body. Enzymes are proteins that make many different chemical reactions in a cell occur for energy.

Carbohydrates Carbohydrates are a group of compounds made of sugars and are used by cells as a source of energy and for energy storage. When an organism needs energy, its cells break down carbohydrates to release the energy. There are two types of carbohydrates: simple & complex

Simple vs. Complex Carbs Carbohydrates Simple carbohydrates are made of one sugar molecule or a few sugar molecules linked together (ex. Sugar in fruits, or sugar used to sweeten coffee) Complex carbohydrates are made of hundreds or thousands of sugar molecules linked together and are stored for later use (ex. starch found in a potato)

Lipids Lipids are a type of biochemical, such as fats and oils, that does not dissolve in water; lipids store energy and make up cell membranes When an organism has used up most of its carbohydrates, it can obtain energy form lipids. Phospholipids are the molecules that form much of the cell membrane, which all cells are surrounded by.

Nucleic Acids Nucleic acids are compounds made up subunits called nucleotides and are often called the blueprints of life because they contain all the information needed for the cell to make all of its proteins. DNA is a nucleic acid. When cells need to make specific proteins, DNA directs how amino acids are linked together to make that protein.

ATP ATP (adenosine triphospate) is the major fuel used for all cell activities that require energy. When food molecules are broken down, some of the energy is transferred to ATP molecules which can be used by cells to fuel their life processes.

Homework: Ch. 2, Section 3 Review Questions: 1. What are the subunits of proteins? or starch? of DNA? 2. What do carbohydrates, fats, and oils have in common? 3. Are all proteins enzymes? Explain your answer. 4. What do you think would happen to the supply of ATP in your cells if you did not eat enough carbohydrates? How would this affect your cells?