1. Chapter 2 Table of Contents Section 1 Characteristics of Living Things
It’s Alive!! Or Is It?
Table of Contents
Section 1 Characteristics of Living Things
Section 2 The Necessities of Life

2. Section 1 Characteristics of Living Things
Chapter 2
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.

3. Section 1 Characteristics of Living Things
Chapter 2
Objectives
Describe the six characteristics of of living things.
Describe how organisms maintain stable internal conditions.
Explain how asexual reproduction differs from sexual reproduction.

4. Living Things Have Cells
Section 1 Characteristics of Living Things
Chapter 2
Living Things Have Cells
All living things are composed of one or more cells.
A cell is a membrane-covered structure that contains all of the materials necessary for life.
Some organisms are made up of only one cell and some are made up of trillions of cells. In an organism with many cells, different kinds of cells perform specialized functions.

5. Living Things Sense and Respond to Change
Section 1 Characteristics of Living Things
Chapter 2
Living Things Sense and Respond to Change
A stimulus is anything that causes a reaction or change in an organism or any part of an organism.
Homeostasis is the maintenance of a stable internal environment.
Responding to External Change Organisms must respond to change in the external environment in order to maintain their homeostasis.

6. Living Things Reproduce
Section 1 Characteristics of Living Things
Chapter 2
Living Things Reproduce
Organisms make other organisms similar to themselves.
In sexual reproduction, two parents produce offspring that will share characteristics of both parents.
In asexual reproduction, a single parent produces offspring that are identical to the parent.

7. Chapter 2 Living Things Have DNA
Section 1 Characteristics of Living Things
Chapter 2
Living Things Have DNA
The cells of all living things contain the molecule deoxyribonucleic acid, or DNA.
DNA controls the structure and function of cells.
The passing of traits through DNA is called heredity.

8. Living Things Use Energy
Section 1 Characteristics of Living Things
Chapter 2
Living Things Use Energy
Organisms use energy to carry out the activities of life.
An organism’s metabolism is the total of all of the chemical activities that the organism performs.

9. Living Things Grow and Develop
Section 1 Characteristics of Living Things
Chapter 2
Living Things Grow and Develop
All living things, whether they are made of one cell or many cells, grow during periods of their lives.
Living things may develop and change as they grow.

10. Chapter 2
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.

11. Chapter 2
Section 2 The Necessities of Life
Objectives
Explain why organisms need food, water, air, and living space.
Describe the chemical building blocks of cells.

12. Chapter 2
Section 2 The Necessities of Life
Water
Your cells and the cells of almost all living organisms are approximately 70% water. Most of the chemical reactions involved in metabolism require water.
Air
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.

13. Chapter 2 A Place to Live Food
Section 2 The Necessities of Life
A Place to Live
All organisms need a place to live that contains all of the things they need to survive. Space on Earth is limited, so organisms are often in competition with each other.
Food
All living things need food. Food gives organism energy and the raw material needed to carry on life processes.

14. Chapter 2 Food, continued
Section 2 The Necessities of Life
Food, continued
Making Food Some organisms, such as plants, are called producers. Producers can make their own food by using energy from their surroundings.
Taking Food Other organisms are called consumers because they must eat (consume) other organisms to get food. Decomposers are consumers that get their food by breaking down the nutrients in dead organisms or animal wastes.

15. Comparing Consumers and Producers
Chapter 2
Section 2 The Necessities of Life
Comparing Consumers and Producers
Click below to watch the Visual Concept.
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Visual Concept

16. Putting It All Together
Chapter 2
Section 2 The Necessities of Life
Putting It All Together
All organisms need to break down that food in order to use the nutrients in it.
Nutrients are made up of molecules.
Molecules found in living things are usually made up of six elements: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

17. Chapter 2
Section 2 The Necessities of Life
Proteins
Proteins are large molecules made up of amino acids.
Making Proteins Organisms break down the proteins in food to supply their cells with amino acids that are then linked together to form new proteins.
Proteins in Action Some proteins form structures that are easy to see. Other proteins help cells do their jobs. Proteins called enzymes start or speed up chemical reactions in cells.

18. Chapter 2 Carbohydrates
Section 2 The Necessities of Life
Carbohydrates
Molecules made of sugars are called 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. Organisms store extra sugar as complex carbohydrates.

19. Chapter 2 Lipids Lipids are compounds that cannot mix with water.
Section 2 The Necessities of Life
Lipids
Lipids are compounds that cannot mix with water.
Phospholipids are the molecules that form much of the cell membrane.
Fats and Oils Fats and oils are lipids that store energy. When an organism has used up most of its carbohydrates, it can get energy from these lipids.

20. Chapter 2
Section 2 The Necessities of Life

21. Chapter 2
Section 2 The Necessities of Life
ATP
Adenosine triphosphate, or ATP, is the major energy-carrying molecule in cells.
The energy in carbohydrates and lipids must first be transferred to ATP, which then provides fuel for cellular activities.

22. Chapter 2
Section 2 The Necessities of Life
Nucleic Acids
Nucleic acids are large molecules made up of subunits called nucleotides.
Nucleic acids are sometimes called the blueprints of life because they have all the information needed for a cell to make proteins.
DNA is a nucleic acid.

23. Chapter 2 Nucleic Acid Section 2 The Necessities of Life
Click below to watch the Visual Concept.
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Visual Concept

24. Chapter 2
It’s Alive!! Or Is It?
Concept Map
Use the terms below to complete the concept map on the next slide.
DNA
sugars
energy
enzymes
living cells
proteins
starches
carbohydrates

25. Chapter 2
It’s Alive!! Or Is It?

26. Chapter 2
It’s Alive!! Or Is It?

27. End of Chapter 2