Section 2 The Necessities of Life Chapter 2 Section 2 The Necessities of Life

Water 70% of your body is made of water. Most chemical reactions require water. Needed water comes from liquids you drink and foods you eat. Survival time without water: 3 days.

Air Air is a mixture of several gasses: oxygen, nitrogen, and carbon dioxide. Oxygen is used to release energy from food. Plants require carbon dioxide. Some organisms do not need air to survive.

A Place to Live All living things need a place to live. Living space depends on size. Living space is selective: must be safe, near food, and water.

Activity: The 3 “Bear” Necessities On the front of the tabs in the title section write: Water, Air, A place to live. Add some color to the bear Cut out the foldable and glue the top of the tab onto page 72. Underneath each tab: Provide an illustration/graphic of the necessity. Provide a description of the necessity and your graphic.

Food Food provides energy and the raw materials needed for life. Nutrients are used to make cells and build body parts. There are three different ways organisms can get food.

Food 4. Producers make their own food through photosynthesis. 5. Plants use the sun’s energy, water, and carbon dioxide to make food. 6. Consumers eat other organisms (plants or animals) to get food.

Food 7. Some consumers obtain food by breaking down nutrients in dead organisms. 8. Decomposers eat the remains of once living things.

Activity: Prod’s, Con’s, Decomp’s Add some color to the front of the foldable (We are only using the larger foldable) Cut out and glue tab against the left handed margin on page 76. Underneath each section of foldable: Write a description of the particular organism. List 3 examples of each, with one of those examples being an illustration/graphic.

Putting It All Together All organisms need to break down food in order to use the nutrients inside. Nutrients are made up of molecules. A molecule is a substance made of two or more atoms. Most molecules are a combination of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

Proteins Proteins are molecules made up of amino acids. Some proteins are broken down to form new proteins. Proteins are responsible for building and repairing body structures. Proteins control many functions in cells and chemical reactions.

Proteins 5. Proteins can form various structures. 6. Proteins help cells do their jobs. 7. Proteins protect cells. 8. Enzymes (proteins) control chemical reactions.

Proteins

Carbohydrates Molecules made up of sugar. Provide and store energy for cells. When carbohydrates are broken down, energy is released. Two types: simple and complex.

Carbohydrates 5. Simple carbohydrates are made of one to a few sugar molecules. 6. Examples: table sugar and fruits. 7. Glucose: most common source of energy for cell.

Carbohydrates 8. Complex carbohydrates are made up of hundreds of sugar molecules. 9. Some plants store extra sugar as starch. 10. Once eaten, starch is broken down to release the energy.

Proteins/Carbohydrates

Activity: Venn Diagram - Carbs vs. Proteins Part 1: On the front of the tab: Write out differences between proteins and carbohydrates. Add a little color to the front of the tab. Cut out and glue onto top of page 78. Underneath the tabs: Create an illustration representing a protein and a carbohydrate. Part 2: Below the Venn Diagram: List your 5 favorite foods Identify your favorites as Carbs or Proteins

Lipids Lipids are molecules of fat that cannot mix with water. Phospholipids form much of the cell membrane. The head of a phospholipid is attracted to water, the tail is not. Phospholipids form a two-layer membrane.

Lipids

Lipids 5. Fats and oils are lipids that store energy. 6. After carbohydrates are burned, fats and oils can be used for energy. 7. Most lipids in plants are oils. 8. Most lipids in animals are fats.

ATP Adenosine Triphosphate (ATP) – major energy carrying molecule of cells. Energy in carbohydrates and lipids is transferred to ATP. ATP provides fuel for cellular activities.

Nucleic Acids Molecules that carry directions to make proteins. Nucleic acids are made of nucleotides. Nucleotides store the information. DNA is a type of nucleic acid.

Activity: Organic Molecules Color the envelope Cut out the title, envelope, and along the diagonal lines. (Page 72) On the text side describe each role and give an example of each.