It Is Alive Or, Is It

1
It Is Alive!! Or, Is It?

• Life Living Things
• Chapter 2
• pages 35 - 45

2
Characteristics of Living ThingsBiogenesis

• Living things come only from living things.
• Spontaneous generation is the theory that lower
  forms of life come from nonliving things.
• Francesco Redi 1667 meat experiment

3
6 Characteristics of Living Things

• Living Things
• Have Cells
• Sense and Respond to Change
• Reproduce
• Have DNA
• Use Energy
• Grow and Develop

4
Looking for the Bare Necessities

• Food provide energy and raw materials to carry
  on life processes
• Water Most chemical reactions involved in
  metabolism require water
• Air Most living things use oxygen in the
  chemical process that releases energy from food
• A Place to Live Must contain all things a
  particular organism needs to survive

5
Surprising Homes

• Antarctica 98 of the continent is covered in
  ice, but it is home to 400 types of lichens and
  85 mosses.
• Death Valley National Park Home to over 900
  plants and 400 animal species despite extreme
  summer heat and average yearly rainfall of less
  than 4 cm.
• 4 kilometers deep in the ocean live jellyfish,
  giant clams, blind fish and red worms.

6
Chemical Menu

• Carbohydrates bodys primary source of energy
• Lipids include saturated and polyunsaturated
  fats
• Nucleic acids contain essential information for
  the construction of proteins
• Proteins made of 20 different amino acids
  arranged in different combinations

7
Proteins

• Most abundant material in cells after water
• Large molecules made up of subunits called amino
  acids
• Proteins form various structures
• Hemoglobin is a protein in red blood cells that
  attaches to oxygen
• Special proteins call enzymes make many chemical
  reactions in the cell occur quickly

8
Carbohydrates

• Group of compounds made of sugars
• Cells use as a source of energy and for energy
  storage
• Two types
• Simple made of one sugar molecule or a few
  molecules linked together (table sugar, sugar in
  fruits)
• Complex made of hundreds of sugar molecules

9
Lipids

• Cannot mix with water
• Many important functions
• Fats and oils store energy
• Most lipids stored in plants are oils (liquid)
• Most lipids stored in animals are fats (solid)
• Phospholipids form cell membrane
• When in water, the tails come together and heads
  face out

10
Nucleic Acids

• Made up of subunits called nucleotides
• Sometimes called the blueprints of life
• Contain all the information needed for the cell
  to make all of its proteins
• DNA is an example of a nucleic acid

11
The Cells Fuel - ATP

• Adenosine Triphosphate
• Major fuel used for cell activities that require
  energy
• Stored energy must be transferred to ATP
  molecules before it can be used by cells