Download Or Is It? Section 1: Characteristics of Living Things (pg 4-7)

Microorganisms, Fungi, and Plants
Chapter 1: It’s Alive!! Or Is It?
Section 1: Characteristics of Living Things (pg 4-7)
Living Things Have Cells

All living things are made of one or more cells.
o A cell is a membrane-covered structure that
contains all of the materials necessary for life
o
In an organism with many cells, different cells
perform specialized functions
Living Things Sense and Respond to Change

All organisms have the ability to sense change in their environment and to
respond to that change.

A change that affects the activity of the organism is called a stimulus.
o Stimulus can be hunger, sounds and light, or anything that
causes organisms to respond in some way
Homeostasis

The maintenance of a stable internal condition is homeostasis
Responding to External Changes

When you get hot, your body responds by sweating.

When you get cold, your body shivers to warm you up.

Humans and other animals have stable internal conditions.
Other animals need to control their body by moving from one
environment to another.
Living Things Reproduce

Organisms make other organisms similar to themselves, either through
sexual or asexual reproduction.

Sexual reproduction is when two parents produce offspring that share
traits from BOTH parents.

Asexual reproduction occurs when a single parent produces offspring
that are IDENTICAL to the parent.
Living Things Have DNA
 The cells of all living things contain the deoxyribo-nucleic acid, or
DNA.
 DNA controls the structure and function of cells.
DNA is a nucleic acid
Nucleic acid is a molecule called the blueprints of life.
Passing DNA ensures that offspring look like their parents. The passing
of traits from one generation to the next is called heredity.
Living Things Use Energy
 Organisms use energy to carry out activities
 An organism’s metabolism is the sum of all the chemical activities a living
thing performs
Living Things Grow and Develop
 All living things grow and develop.

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Section 2: The Necessities of Life (pg 8-11)
Water

Your body is made of mostly water.

Your cells and the cells of almost all living organisms are about 70%
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. Oxygen may come from the air or may be dissolved in water.

Green plants, algae, and some bacteria need carbon dioxide gas in
addition to oxygen. These organisms produce food and oxygen by using
photosynthesis.

In photosynthesis, green organisms convert the energy in sunlight to
energy stored in food.

Organisms that can live without air are anaerobic organisms.
A Place to Live

All organisms need a place to live that contains all of the following things
they need to survive.

Space on Earth is limited, so organisms often compete with each other
for food, water, and other necessitates.
Food

All living things need food.

Food gives organisms energy and the raw materials needed to
carry on life processes.

Organisms use nutrients from food to replace cells and build body parts.
o Making Food

Some organisms, such as plants are producers. Producers
can make their own food by using energy from its
surroundings.
o Taking Food

Other organisms are called consumers because they must eat
(consume) other organisms to get food.

Some consumers are decomposers. Decomposers are
organisms that get their food by breaking down the nutrients
in dead organisms or animal waste and absorbing the
nutrients.
Putting It All Together

Food, water, air, and a place to live are basic needs of most living things.

All organisms need to break down their food in order to use the
nutrients in it.

Nutrients are made up of molecules. A molecule is a substance made
when two or more atoms combine.

Molecules made of different kinds of atoms are compounds.

Molecules found in living things are usually made of different
combinations of six elements: carbon, hydrogen, nitrogen, oxygen,
phosphorous, and sulfur. These elements combine to form proteins,
carbohydrates, lipids, ATP, and nucleic acids.
Proteins

Almost all of my processes of a cell involve proteins. Proteins are large
molecules that are made up of smaller molecules called amino acids.
o Making Proteins

Organisms break down the proteins in foods to supply their
cells with amino acids. Amino acids are linked together to
form new proteins.
o Proteins in Action
Proteins have many different functions. Some proteins form

structures that are easy to see. Other proteins are very small
and help cells do their job.
Inside red blood cells, the protein

hemoglobin binds to oxygen to deliver and
release oxygen through the body.
Other proteins, called enzymes, start or speed up chemical

reactions in cells.
Carbohydrates

Molecules made of sugars are called carbohydrates. Cells use
carbohydrates as a source of energy and for energy storage.

There are two kinds of carbohydrates- simple carbohydrates and complex
carbohydrates.
o Simple Carbohydrates

Simple carbohydrates are made up of one sugar molecule or
few sugar molecules linked together.
o Complex Carbohydrates

When an organism has more sugar than
it needs, its extra sugar may be stored
as complex carbohydrates. Complex
carbohydrates are made of hundreds
of sugar molecules linked together.
Lipids
 Lipids are compounds that cannon mix with water. Fats and steroids are
lipids.
o Phospholipids

All cells are surrounded by a cell membrane. Phospholipids
are the molecules that form much of the cell membrane.
o 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.
ATP

Adenosine triphosphate, or ATP, is another important molecule. ATP is
the major energy-carrying molecule in the cell. Energy from carbohydrates
and lipids are transferred to ATP, which then provides fuel for cellular
activity
Nucleic Acids

Nucleic acids are called the blueprints of life because they all have the
information needed for a cell to make proteins.

Nucleic acids are large molecules made up of molecules called
nucleotides. A nucleic acid may have thousands of nucleotides.