Download The Necessities of Life

Is it living or nonliving? That is the question.
How can you tell?
http://ny.pbslearningmedia.org/resource/tdc02.sci.life.colt.alive/is-it-alive/
Remember: cred gr
Discussion Questions
Do any nonliving things possess characteristics of living
things? Give examples.
How were the living things different from the nonliving
things?
What characteristics did ALL of the living things have in
common?
The Necessities of Life
The Bare Necessities
http://viewpure.com/9ogQ0uge06o?start=0&end=0
The Necessities of Life
The Necessities of Life
• Water
• Air
• A Place to Live
• Food
Water
• Your body is approximately 70% water.
• Most chemical reactions involved in
metabolism require water.
• You would survive only about 3 days without
water.
Air
• Most living things use
oxygen to release energy
from food.
• Organisms living on land get
oxygen from the air
• Organisms living in water either
come to the surface to get oxygen from the air or take in
dissolved oxygen from the water.
• Green plants need Carbon dioxide and oxygen. During
the process of photosynthesis, they convert the energy in
sunlight to food.
A Place to Live
• All organisms need a
place to live that
contains all the things
they need to survive.
• Space is limited
Organisms often compete
for food, water and
other necessities.
Food
• Food gives organisms energy and the raw materials
needed to perform life processes.
• Organisms use nutrients to replace cells and to build
body parts.
• Producers – Make their own food. Plants use energy from the
sun to make food from water and carbon dioxide.
• Consumers – Gets its energy from eating or consuming other
organisms (MOST ANIMALS)
• Decomposers – These are consumers that break down
nutrients in dead organisms and animal waste (MUSHROOMS)
YOU’RE NOT YOU WHEN YOU ARE HUNGRY
Molecules and Nutrients
• All organisms must break down 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 two or more different atoms
are compounds.
• Molecules in living things are made up of a
combination of carbon, hydrogen, nitrogen,
oxygen, phosphorus and/or sulfur.
Building Blocks of Cells
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Proteins
Carbohydrates
Lipids
ATP
Nucleic Acids
Proteins
• Proteins are made up of smaller molecules called amino
acids.
• Enzymes are proteins that speed up chemical
reactions
• Proteins are needed to build and repair body structures
and to regulate processes in the body.
• Hemoglobin is a protein found in red blood cells that
attaches to oxygen
• Spider webs, hair, horns,
and feathers are made
of proteins.
Carbohydrates
Energy giving nutrients such as sugars, starches and fiber are
carbohydrates.
• Molecules made of sugars are called carbohydrates.
• Cells use these as a source of energy and for energy storage.
• Simple Carbohydrates – Table sugar and the sugar in fruit
When an organism has more sugar than it needs,
its extra sugar is stored as a Complex Carbohydrate. Potatoes
store the extra sugar as starch. Your body breaks this down to
release the energy stored in the potato.
Lipids
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(fat lips)
Cannot mix with water
Fats, oils are lipids that STORE energy
Most lipids stored in plants are oils
Most lipids stored in animals are fats
Some form the membrane of cells
Phospholipids
Form the cell membrane
ATP – Carries Energy
• Major energy carrying molecule in the cell.
• Provides fuel for cellular activities when the
energy in carbohydrates and lipids is
transferred to ATP.
Nucleic Acids
• Molecules consisting of subunits called
nucleotides are nucleic acids
• The blueprints of life.
• They contain all the information needed for a
cell to make proteins
• DNA is a nucleic acid