Chapter 1 Cells: The Basic

Units of Life

1.) Cells – smallest living thing

2.) Tissues – many cells working together

3.) Organ – many tissues working together (stomach, heart, lungs, skin)

4.) Organ systems – many organs working together (nervous & digestive system)

Levels of Organization

5.) Organism – many organ systems

6.) Population- same organisms living in same area

7.) Community- two or more different populations.

8.) Ecosystem- a community & all the nonliving things that affect it.

•Terrestrial•Aquatic

•Organism-anything that can live on its own.

•Unicellular-a single cell living on its own (ex. bacteria)

•Multicellular- many cells living as a group of cells (ex. plants & animals)

Vocabulary

• Hooke was the first to discover cells in 1665 by looking at a piece of cork.

• The invention of the microscope was necessary and lead to the discovery of cells because they are too small to see with the naked eye.

Discovery of CellsRobert Hooke

Image of Cork Cells

• Dutch merchant• He looked at: pond scum, blood, & yeast in 1673.• He saw small “animals” in pond scum and called them “animalcules”

Other Facts:– Made own microscope– First to see bacteria– Discovered yeast is unicellular

Discovery of CellsAnton von Leeuwenhoek

Cell TheoryThe three people to discover the cell theory

are:

Matthias Schleiden

Theodor Schwann

Rudolf Virchow

3 Parts of the Cell Theory

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.

Two Types of Cell

Prokaryotic Cells

Eukaryotic Cells

No Nucleus Nucleus

No membrane-covered organelles

Membrane-covered organelles

Circular DNA Linear DNA

Example: Bacteria Example: All cells other than bacteria

Eukaryotic Cell

Prokaryotic Cell

Parts of a Cell

Animal CellAnimal Cell

Plant CellPlant Cell

• Structures in the cell that perform specific functions within the cell

Organelles

• Protective layer that surrounds all cells• Separates cells from their environment• Controls materials going into & out of the

cell

Cell Membrane

• Jelly-like fluid in the cell• Holds the organelles in place

Cytoplasm

• Web of proteins in the cytoplasm• Maintains structure of cell

Cytoskeleton

• A system of folded membrane that is used for lipid (fat) transport.

• There are no ribosomes

Smooth Endoplasmic Reticulum

• Smallest & most numerous organelles• Some float freely in cytoplasm• Some are attached to the Rough ER• Their function is to make proteins out of

amino acids

Ribosomes

• A system of folded membranes which are covered in ribosomes

• Used for protein transport

Rough Endoplasmic Reticulum

• Packages lipids and proteins in small bubbles which may be used somewhere else inside or outside of the cell

• Looks like smooth ER

Golgi Complex

• Bubbles that form from the Golgi complex’s membrane

• Surrounds material to be moved into or out of a cell

Vesicle

• Power house of the cell that breaks down sugar to produce energy in the form of ATP (Adenosine triphosphate)

• * All The Power

Mitochondria

•Stores water•Much larger in

plant cells than in animal cells

Vacuoles

• Contain digestive enzymes• Responsible for digestion

and getting rid of waste

Lysosome

• Controls the cell• Contains DNA (deoxyribonucleic acid)

which is the genetic material that carries information

• Surrounded by a nuclear membrane that contains pores

Nucleus

• Dark area in the nucleus• Produces ribosomes

Nucleolus

• Inside the nucleus• Contain genes in two forms:

– Chromatin: (thread-like substance) that DNA is typically shaped like

– Chromosomes: (X-shaped substance) that DNA takes the form of when the cell is dividing

DNA

Chromatin Chromosomes

• Outermost layer of PLANT cells (as well as fungi and some prokaryotes)

• Gives shape & support to cells • Contains cellulose

Cell Wall

• Green organelle in plant cells only• Responsible for photosynthesis –

process by which plants use sunlight, carbon dioxide, & water to make sugar & oxygen

• Contain chlorophyll

Chloroplasts

Cells Alive!