Cell Structure

& Function

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

Cell Theory

• All living things are made of cells.

• Cells are the smallest units of life

• All cells come from preexisting cells.

Cell Theory Scientists

• Hooke – named cells after viewing cork

under a microscope

• Leeuwenhook – saw living cells and called

them “animalcules”

• Schwann – concluded that animals were

made of cells

• Schleiden – concluded that plants were

made of cells

• Virchow – determined that cells only came

from pre-existing cells

Definition of Cell

The smallest unit capable of life.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Two Types of Cells

•Prokaryotic

(leave space)

•Eukaryotic

Prokaryotic

• No membrane bound structures

• No organelles or nucleus

• One-celled organisms, Bacteria

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

Eukaryotic • Contain organelles surrounded by membranes

• Most living organisms, single or multi-celled

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

Eukaryotic

Organelles

Surrounding the Cell

Cell Membrane

• All cells

• Outer part of cell that

controls movement in

and out of the cell

• Made of a double layer

called Phospholipid

bilayer

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

Cell Wall

• Found in eukaryote

plant & some

prokaryotes only

• Supports cell

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

Inside the Cell

Nucleus

• Eukaryotes only

• Directs cell activities

• Separated from cytoplasm by nuclear

membrane

• Contains DNA (genetic instructions)

Nuclear Membrane

• Eukaryotes only

• Surrounds nucleus

• Made of two layers

• Openings allow RNA

to enter and leave

nucleus

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

Nucleolus

• Eukaryotes Only

• Inside nucleus

• Makes ribosomes

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

Cytoplasm

• All cells

• Gel-like mixture that fills cell

• Site of some chemical reactions

Endoplasmic Reticulum • Eukaryotes only

• Moves materials around

within cell to help

assemble proteins and

lipids

• Smooth type: lacks

ribosomes

• Rough type (pictured):

ribosomes embedded in

surface

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

Ribosomes

• All Cells

• Each cell contains

thousands

• Make proteins

• Found on ER &

floating throughout

the cell

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

Mitochondria

• Eukaryotes Only

• Produces energy (ATP)

from sugar (glucose)

through cell respiration

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

Golgi Bodies

• Eukaryotes Only

• Protein “package and

ship”

• Move materials in

and out of the cell

(like the post office)

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

Lysosome • Eukaryotes only

• Digests/Destroys worn

out parts, proteins, fats,

and carbohydrates

• Cell breaks down if

lysosome explodes

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

Vacuoles

• Eukaryotes only

• Membrane-bound

sacs for storage

(especially water in

plant cells)

• Help plants maintain

shape

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

Chloroplast

• Eukaryotic plant cells

only

• Contains green

chlorophyll

• Site of photosynthesis

(where light energy is

converted to

carbohydrate energy)

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

Centriole (Centrosome)

• Eukaryotic Animal

Cells ONLY

• Helps with cell

division

Microtubule & Microfilament

• Eukaryotic Cells

only

• Make up

cytoskeleton

• Interior Support

Strike through Nuclear Pores

and add… • Cilia

– All cells (optional)

– Hair-like, for

movement

• Flagella

– All cells (optional)

– Tail-like, for

movement

Group Project – The ____ is like

a _____, because _______. • Make analogies for

the following

organelles

– Nucleus

– Nucleolus

– Endoplasmic

reticulum

– Golgi

– vacuole

– Cytoplasm

– Ribosomes

– Cytoskeleton

– Chrolorplast

– Centriole

– Cell membrane

– Lysosomes

– Mitochondria

– Cell wall