Download The Necessities of Life

The Necessities of Life
Book A-Chapter 1-Section 2
Discussion
 What
 Do
needs to humans have?
we have the same needs as animals?
Water




The body is mostly made up of water
Cells are 70% water
Most chemical reactions having to do with metabolism require water
Different organisms require different amounts of water
Example of different water intake:
humans vs. camels


Humans can only survive for about 3 days without water
Camels don’t drink water during the whole winter! During the
hottest part of the summer, they can go for a week without water!
Air
 Air
is a mixture of gases
 Most organisms require oxygen and get it from
either air or water
 Green plants, algae, and some bacteria need carbon
dioxide gas in addition to oxygen
 These organisms produce food and oxygen by
using photosynthesis-or converting energy in
sunlight to energy stored in food
A place to live
 All
living things need a place to live
 Some move around, and some stay in the same
place throughout the duration of their life
 Example: the Warbler
Food

All living things need food

Food provides organisms with energy

Organisms use nutrients from food to replace cells and
build body parts

Not all animals get food in the same way
Producers
Some organisms, such as plants, are called producers
 PRODUCERS: make own food by using energy from its
surroundings
 Plants use energy from the sun to make food from water
and carbon dioxide

Consumers
 CONSUMERS:
organisms that eat other organisms
or organic matter
Decomposers
Some consumers are decomposers
 DECOMPOSERS are organisms that get their food by breaking down the remains
of dead organisms or animal wastes and consuming or absorbing the nutrients
Earthworms, fungi, termites, bacteria

Brainpop video
 http://www.brainpop.com/science/populationsreso
urcesandenvironment/foodchains/zoom.weml
Nutrients
All organisms eat to get nutrients
 Nutrients are made up of molecules
 A molecule is a substance when two or more atoms
combine
 Molecules 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, phosphorus, and sulfur.
 These elements combine to form proteins, carbohydrates,
lipids, ATP, and nucleic acid

Proteins
 PROTEIN:
a molecule that is made up of amino
acids and that is needed to build and repair body
structures and to regulate processes in the body
 Animals
break down proteins with amino acids
Proteins in Action
 Some
proteins have visible functions:
Proteins in Action (2)
 Other
proteins are small and help cells do their
jobs
 Inside blood, the red protein, hemoglobin, bind to
oxygen to deliver and release oxygen throughout
the body
 Some proteins protect cells
 Other proteins, called enzymes start or speed up
chemical reactions
Carbohydrates
 CARBOHYDRATES:
a class of energy-giving
nutrients that includes sugars, starches, and fiber;
contains carbon, hydrogen, and oxygen
 There
are two kinds of carbohydrates: simple and
complex
Simple Carbohydrates
 Made
up of one sugar molecule or a few sugar
molecules linked together
 Table sugar and sugar in fruits are examples
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
Brainpop video
 http://www.brainpop.com/health/personalhealth/ca
rbohydrates/
Lipids
 LIPIDS:
a type of biochemical that does not
dissolve in water; fats and steroids are lipids
 Some
lipids store energy
 Other
lipids form cell membranes
Phospholipids
 All
cells are surrounded by a membrane
 Membrane helps protect the cell from the outside
environment
 PHOSPOLIPIDS:a lipid that contains phosphorus
and that is a structural component in cell
membranes
Fats and Oils
 Fats
and Oils are lipids that store energy
 When an organism has burned through its
carbohydrates, it can get energy from these lipids
 The structure of fats and oils are almost the same,
but at room temperature, most fats are solid, and
most oils are liquid
 Most of the lipids stored in plants are oils
 Most of the lipids stored in animals are fats
ATP
ATP=adenosine triphosphate
 ATP-the major energy carrying molecule in the cell
 The energy in carbs and lipids must be transferred to ATP
which provides fuel for cellular activity

Nucleic Acids
Sometimes called the “blueprints” of life because they
have all the information needed for a cell to make proteins
 NUCLEIC ACID-a molecule made up of subunits called
nucleotides
 DNA is a nucleic acid that provides information on how to
make a DNA
 The order of nucleotides tells the cell the order of the
amino acids that are linked together to make that protein
