1. Cells: the Basic Units of Life
Chapter 3
Cells: the Basic Units of Life

2. Section 1 – Organization of Life Vocabulary Words
Tissue – Group of cells that work together to perform a specific job in the body
Organ – When two or more tissues work together this group of tissues is called an organ
Organ System – Organs working together to perform a specific job
Organism – Anything that can live on its own
Unicellular – A single cell living on its own
Multicellular – Can only exist as a group of cells
Population – Group of organisms that are the same kind living in the same environment
Community – Two or more different populations living in the same environment
Ecosystem – The community and all the nonliving things that affect it
Section 1 – Organization of Life Vocabulary Words

3. Cells to Tissues to Organs to Organ Systems to Organisms
Populations vs. Communities vs. Ecosystems
Organization of life

4. Section 2 – The Discovery of Cells Vocabulary Words
Cell Membrane – Surround a cell and acts as a barrier
Organelles - Structures that enable the cell to live, grow, and reproduce
Cytoplasm – The fluid and almost everything in it
Nucleus – Membrane covered organelle that holds the cells’ DNA
Prokaryotic – Cells that do not have a nucleus
Eukaryotic – Cells that have a nucleus
Bacteria – extremely small,single celled organisms without a nucleus; prokaryotic cell
Section 2 – The Discovery of Cells Vocabulary Words

5. The First Cells were discovered by Robert Hooke in 1665 and were cork cells
The Cell Theory was written by Theodor Schwann and it states:
1. All organisms are composed of one or more cells
2. The cell is the basic unit of life in all living things
3. All cells come from existing cells
4. All cells have a: cell membrane, Hereditary material (DNA), Cytoplasm and Organelles, small size
Cell Theory

6. There are two types of cells:
PROKARYOTIC: No nucleus
No membrane – covered organelles
Circular DNA
All prokaryotes are bacteria
EUKARYOTIC: Nucleus
Membrane-covered organelles
Linear DNA
All other cells

7. Section 3 – Eukaryotic Cells: The Inside Story
Cell Wall – Provides strength and support to the cell membrane: found only in plants
Ribosome –Smallest but most abundant organelles where proteins are made from amino acids
Endoplasmic Reticulum – Membrane covered organelle that makes lipids and other materials for use inside and outside the cell
Mitochondria – Cell Organelles surrounded by two membranes that break down food molecules to make ATP
Chloroplast –Energy converting organelle found in plants and algae: found only in plants
Golgi Complex – Ships proteins and other materials out of the cell
Vesicle – A membrane covered compartment in a eukaryotic cell that forms when part of the cell membrane surrounds an object and pinches off
Vacuole – A large membrane covered structure found in plants cells that serves as a storage container for water and other liquids
Lysosome - A special vesicle in a cell that digests food particles, wastes, and foreign invaders
Section 3 – Eukaryotic Cells: The Inside Story

8. Organelles and their Functions
Nucleus – Contains the cell’s DNA and is the control center of the cell
Ribosomes – The site where amino acids are hooked together to make proteins
Endoplasmic Reticulum – Makes lipids, breaks down drugs and other substances, packages up proteins for release from the cell.
Mitochondria – Break down food molecules to make ATP
Chloroplasts – Make food using the energy of sunlight: found only in plants
Golgi Complex – Processes and transports materials out of the cell
Vacuole – Stores water and other materials
Lysosomes – Digest food particles, wastes, cell parts, and foreign invaders