Cell Structure and Function

Chapter 4

History of Cell Biology

Section 1

Hooke microscope

Leeuwenhoek microscope

The cork “little boxes”

19th century scientists

Schleiden concluded: 1838 - All plants were composed of cells

Schwann concluded: 1839 - All animals were composed of cells

Virchow concluded: 1855 - All cells come from other cells

The Cell Theory

1. All living organisms are composed

of at least 1 or more cells

2. Cells are the basic unit of life

3. Cells only come from pre-existing

cells

Introduction to Cells

Section 2

Cell Diversity

Diversity of cell shape

bacterial cell shapes

algal cell shapes

Diversity of cell size

10-9 10-6 10-3

Comparison of some cell sizes

Limits to cell sizeSurface Area : Volume ratio

Best ratio is a big number

Big  Number  = Surface   AreaVolume  

Two Kinds of Cells

Comparing Size

Prokaryotes “before kernal /nucleus”

Very primitive cell

Have no true nucleus

DNA is organized in a

region- nucleoid

The bacteria are our

prokaryotes

Eukaryotes “true kernal /nucleus”

Advanced cells

DNA in a nucleus

surrounded

by a membrane

Most organelles have

membranes

All other cells

How cells are organized

Many organisms remain single-celled

How cells are organized

Some organisms have organized into colonies

How cells are organized

Many organisms are multi-celled

Cell tasks for multi-celled organisms

Multi-celled organisms with cell group tasks:

The simplest group of performing cells - tissues

Groups of performing tissues – organs

Groups of performing organs – organ systems

Groups of performing organ systems – organisms

Cells - tissues – organs – organ systems -

organisms

Cell Organelles

Section 3

The animal cell

Plasma Membrane

Fluid Mosaic model

Nucleus

Mitochondria

Ribosomes

Endoplasmic Reticulum - rough

Endoplasmic reticulum - smooth

Golgi apparatus

Vesicles

Cytoskeleton

Cilia

Flagella

Unique Features of Plant Cells

Section 4

Plant Cells

Cell Structure and Function

End - - Chapter 4