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How to Use This Presentation • To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F5 on the top row of your keyboard. • To advance to the next slide click the left mouse button once. • From the Chapter screen you can click on any section to go directly to that section’s presentation. • Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. • You may exit the slide show at any time by pressing the Esc key Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 2 It’s Alive!! Or Is It? Section 1: Characteristics of Living Things Section 2: The Necessities of Life End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Bellringer What are four living and nonliving things that you interact with every day? How do you know whether each is living or nonliving? Do you know what the word inanimate means? If so, write out a definition. Does nonliving mean the same thing as dead? Explain your answer. Write your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Objectives • Describe the six characteristics of of living things. • Describe how organisms maintain stable internal conditions. • Explain how asexual reproduction differs from sexual reproduction. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Living Things Have Cells • What Is a Cell? A cell is a membrane-covered structure that contains all of the materials necessary for life. • How Many Cells? Some organisms are made up of only one cell and some are made up of trillions of cells. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Living Things Sense and Respond to Change • Homeostasis The maintenance of a stable internal environment is called homeostasis. • Responding to External Change Organisms must respond to change in the external environment in order to maintain their homeostasis. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Living Things Reproduce • Having Offspring Organisms make other organisms similar to themselves. They do so in one of two ways: by sexual reproduction or by asexual reproduction. Living Things Have DNA • DNA in Cells The cells of all living things contain the molecule deoxyribonucleic acid, or DNA. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 Characteristics of Living Things Living Things Use Energy • Energetic Organisms Organisms use energy to carry out the activities of life. Living Things Grow and Develop • Growing Up All living things, whether they are made of one cell or many cells, grow during periods of their lives. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Bellringer What do you think your mass would be if there were no water in your body? What else besides water is your body composed of? Where do you think you get the minerals that make up your body mass? Record your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Objectives • Explain why organisms need food, water, air, and living space. • Describe the chemical building blocks of cells. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Water • Thirsty Cells Your cells and the cells of almost all living organisms are approximately 70% water. Air • Oxygen Air is a mixture of several different gases, including oxygen and carbon dioxide. Most living things use oxygen in the chemical process that releases energy from food. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life A Place to Live • Home Sweet Home All organisms need a place to live that contains all of the things they need to survive. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Food • Making Food Some organisms, such as plants, are called producers. Producers can make their own food. • Taking Food Other organisms are called consumers because they must eat (consume) other organisms to get food. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Putting It All Together • Using Nutrients Some organisms make their own food. Some organisms get food from eating other organisms. But all organisms need to break down that food in order to use the nutrients in it. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Proteins • Making Proteins Organisms break down the proteins in food to supply their cells with amino acids. These amino acids are then linked together to form new proteins. • Proteins in Action Proteins have many different functions. Other proteins are very small and help cells do their jobs. Other proteins, called enzymes, start or speed up chemical reactions in cells. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Carbohydrates • Simple Carbohydrates Simple carbohydrates are made up of one sugar molecule or a few sugar molecules linked together. • Complex Carbohydrates Complex carbohydrates are made of hundreds of sugar molecules linked together. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Lipids • Phospholipids Phospholipids are the molecules that form much of the cell membrane. A phospholipid’s membrane is shown on the next slide. • Fats and Oils Fats and oils are lipids that store energy. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Phospholipid Molecules and Cell Membrane Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 The Necessities of Life Nucleic Acids • What Are Nucleic Acids? Nucleic acids are large molecules made up of molecules called nucleotides. • Blueprints of Life Nucleic acids are sometimes called the blueprints of life because they have all the information needed for a cell to make proteins. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 2 It’s Alive!! Or Is It? Concept Map Use the following terms to complete the concept map on the next slide: DNA, sugars, energy, enzymes, living cells proteins, starches, carbohydrates. Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 2 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 2 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved.