Introduction to Cells

Cell Structure

& Function

http://koning.ecsu.ctstateu.edu/cell/cell.html

Cell Theory

• All living things are made up of cells.
• Cells are the smallest working units of all

living things.

• All cells come from preexisting cells

through cell division.

Definition of Cell

A cell is the smallest unit that is

capable of performing life

functions.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Two Types of Cells

•Prokaryotic
•Eukaryotic

Prokaryotic

• Do not have

structures
surrounded by
membranes

• Few internal

structures

• One-celled

organisms,
Bacteria

http://library.thinkquest.org/C004535/prokaryotic_cells.html

Eukaryotic

• Contain organelles surrounded by membranes
• Most living organisms

Plant

Animal

http://library.thinkquest.org/C004535/eukaryotic_cells.html

“Typical” Animal Cell

http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

http://waynesword.palomar.edu/images/plant3.gif

“Typical” Plant Cell

Cell Parts

Organelles

Open Ended

Can you name any organelles?

Surrounding the Cell

Cell Membrane

• Outer membrane of cell

that controls movement
in and out of the cell

• Double layer

http://library.thinkquest.org/12413/structures.html

Cell Wall

• Most commonly found

in plant cells &
bacteria

• Supports & protects

cells

http://library.thinkquest.org/12413/structures.html

Inside the Cell

Nucleus

• Directs cell activities
• Separated from cytoplasm by nuclear

membrane

• Contains genetic material - DNA

Nuclear Membrane

• Surrounds nucleus
• Made of two layers
• Openings allow

material to enter and
leave nucleus

http://library.thinkquest.org/12413/structures.html

Chromosomes

• In nucleus
• Made of DNA
• Contain instructions

for traits &
characteristics

http://library.thinkquest.org/12413/structures.html

Nucleolus

• Inside nucleus
• Contains RNA to build

proteins

http://library.thinkquest.org/12413/structures.html

Cytoplasm

• Gel-like mixture
• Surrounded by cell membrane
• Contains hereditary material

Endoplasmic Reticulum

• Moves materials around

in cell

• Smooth type: lacks

ribosomes

• Rough type (pictured):

ribosomes embedded in
surface

http://library.thinkquest.org/12413/structures.html

Ribosomes

• Each cell contains

thousands

• Make proteins
• Found on ribosomes

& floating throughout
the cell

http://library.thinkquest.org/12413/structures.html

Mitochondria

• Produces energy through

chemical reactions –
breaking down fats &
carbohydrates

• Controls level of water and

other materials in cell

• Recycles and decomposes

proteins, fats, and
carbohydrates

http://library.thinkquest.org/12413/structures.html

Golgi Bodies

• Protein 'packaging

plant'

• Move materials within

the cell

• Move materials out of

the cell

http://library.thinkquest.org/12413/structures.html

Lysosome

• Digestive 'plant' for

proteins, fats, and
carbohydrates

• Transports undigested

material to cell
membrane for removal

• Cell breaks down if

lysosome explodes

http://library.thinkquest.org/12413/structures.html

Vacuoles

• Membrane-bound

sacs for storage,
digestion, and waste
removal

• Contains water

solution

• Help plants maintain

shape

http://library.thinkquest.org/12413/structures.html

Chloroplast

• Usually found in plant

cells

• Contains green

chlorophyll

• Where photosynthesis

takes place

http://library.thinkquest.org/12413/structures.html

Poll

How are you feeling about your knowledge of cells so far?

• I am an expert! Cell Master!

• I feel confident that I know some things

• I am unsure

• I am so lost