Characteristics of Living
Things
All organisms:
• are made of 1 or more cells.
• need a source of energy for life processes.
• must respond to their environment to
survive.
• must have the ability to reproduce.
Cell Theory
Major Principles
1. All organisms are made of cells.
2. All existing cells are produced by other
living cells.
3. The cell is the most basic unit of life.
Cell Types
• Prokaryotes
 No membrane-bound nucleus or organelles
• Eukaryotes
 Made up of one or more cells
 Nucleus & membrane-bound organelles
Prokaryote
Eukaryote
Parts of the Cell
• All cell types have:
 Plasma Membrane - cells outer boundary
 Cytoplasm - fluid inside the cell
 Control center - nucleus in eukaryotic cells,
DNA in cytoplasm in prokaryotic cells
• Only eukaryotic cells have organelles
Plasma Membrane
Controls what
goes in and out
of the cell
Cytoplasm
•Cell’s liquid
interior
•Contains the
cytoskeleton
•Contains
organelles
Nucleus
In Eukaryotic
Cells
Controls all cell’s
activities
Contains DNA
Nuclear Envelope
Separates
DNA from
cytoplasm in the
nucleus
Nucleolus
•In the nucleus
•Made of proteins
& nucleic acids
•Ribosome
synthesis
Ribosome
•Contains RNA
•Helps build proteins
•Made in the nucleolus
Mitochondrion
•Generates ATP
(energy)
•Controls cell cycle &
cell growth
•Inherited from your
mother
Endoplasmic Reticulum (ER)
Production &
movement of
proteins
throughout the
cell
Golgi Apparatus
Processes & packages
lipids & proteins
Lysosome
Digests food & worn-out cell
parts for the cell
Cilia & Flagella
Cilia
•Single-celled organisms
•Helps move the cell
around
•Cilia – many & short
Flagella
•Flagella – few & long
Cell Wall
•Outside of the cell
membrane
•Provides support &
protection
•Plant cells
Central Vacuole
•Storage unit
for cells
•Contains
wastes, food, or
water
Chloroplast
Conducts
photosynthesis