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 CellsAmoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Two Types of Cells

•Prokaryotic•Eukaryotic

Prokaryotic• No membrane

bound organelles• No nucleus (the

DNA floats in the cytoplasm)

• Few internal structures

• One-celled organisms, Bacteria

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

Eukaryotic• Contain organelles surrounded by membranes• Has DNA enclosed in a nucleus• Most living organisms Ex: Plants Animals Protists and Fungi

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

OrganellesStructures in the cell

with a specific function

Surrounding the Cell

#4 Cell Membrane• Outer membrane of cell

that controls movement in and out of the cell

• Separates cell from environment

• “Gatekeeper”

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

#5. Cell Wall• Most commonly

found in plant cells & bacteria

• Supports & protects cells

• Non-living. Made of cellulose

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

Inside the Cell

#3. Nucleus with nuclear membrane • Directs cell activities• Separated from cytoplasm by nuclear

membrane• Contains genetic material – DNA• The “Control Center”

Nuclear Envelopeor Nuclear Membrane

• Surrounds and protects nucleus

• Made of two layers• Openings allow

material to enter and leave nucleus

• “Mini Gate Keeper”

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

#11. DNA-Chromatin (relaxed) or Chromosomes

• In nucleus• Made of DNA• Contain instructions

for traits & characteristics

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

#1. Cytoplasm• Gel-like mixture that holds the organelles

in the cell• Surrounded by cell membrane• “Jello”

#10. Endoplasmic Reticulum• Moves materials around

in cell• Cavities connected to

nuclear envelope• Smooth type: lacks

ribosomes• Rough type (pictured):

ribosomes embedded in surface

• “Subway System”http://library.thinkquest.org/12413/structures.html

#8. Ribosomes• Each cell contains

thousands• Make proteins• Found on ER &

floating throughout the cell

• “The Protein Factories”

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

#2. Mitochondria• Produces energy (ATP)

through cellular respiration – breaking down fats & carbohydrates (glucose)

• “The Powerhouse”

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

#7. Golgi Bodiesor Golgi Apparatus

• Protein 'packaging plant'

• Packs proteins so they can be sent out of the cell

• “Fed Ex” or “Packers”

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

#9. Lysosome• Digestive 'plant' for

proteins, fats, and carbohydrates

• Digest proteins and worn out parts of the cell

• “Digestive System” or “Clean-up Crew”

• Mainly in animal cells

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

#6. Vacuoles• Membrane-bound

sacs for storing food, water, and waste

• Very large in plant cells. Smaller in animal cells

• Help plants maintain shape

• “Storage tank”

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

#12. Chloroplast• Usually found in plant

cells• Contains green

pigment ‘chlorophyll’ that traps energy from the sun

• Where photosynthesis takes place

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