Preview

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Its Alive!! Or Is It?
Chapter 2
Preview
Section 1 Characteristics of Living
Things Section 2 The Necessities of Life
Concept Mapping
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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.

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Section 1 Characteristics of Living Things
Chapter 2
Objectives

• Describe the six characteristics of living
  things.
• Describe how organisms maintain stable internal
  conditions.
• Explain how asexual reproduction differs from
  sexual reproduction.

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Section 1 Characteristics of Living Things
Chapter 2
Living Things Have Cells

• All living things are composed of one or more
  cells.
• Unicellular organisms made of only 1 cell
• Multicellular organisms made of 2 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.

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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.

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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.

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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.

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Section 1 Characteristics of Living Things
Chapter 2
Living Things Use Energy

• Organisms use energy to carry out the activities
  of life.
• An organisms metabolism is the total of all of
  the chemical activities that the organism
  performs.

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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.

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
Objectives

• Explain why organisms need food, water, air, and
  living space.
• Describe the chemical building blocks of cells.

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
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.

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

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
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.

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

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Section 2 The Necessities of Life
Chapter 2
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.

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Section 2 The Necessities of Life
Chapter 2
Nucleic Acid
Click below to watch the Visual Concept.
Visual Concept
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Its Alive!! Or Is It?
Chapter 2
Concept Mapping
Use the terms below to complete the concept map
on the next slide.
DNA sugars energy enzymes living cells proteins starches carbohydrates

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Chapter 2
Its Alive!! Or Is It?
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Chapter 2
Its Alive!! Or Is It?