Cell Structure & Function

Outcome addressed today!!

• 304-4 illustrate and explain that the cell is a living system that exhibits all of the characteristic of life.

Cell Theory

• All living things are made up of cells.

1) Cells are the smallest working units of all living things.

2) 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.

WHAT IS AN ORGANISM?

• a living thing that has (or can develop) the ability to act or function independently

• An individual living system, such as animal, plant or micro-organism, that is capable of reproduction, growth and maintenance.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

Plant Animal

“Typical” Animal Cell

“Typical” Plant Cell

Cell Parts

Organelles

Surrounding the Cell

Cell Membrane

• Outer membrane of cell that controls movement of materials in and out of the cell

• Double layer

Cell Wall

• Found in plant cells & bacteria

• Supports cells (outer layer)

• Protects against water loss

Inside the Cell

Nucleus

• Directs cell activities

• Near the center of the cell

• Contains genetic material - DNA

Nuclear Membrane

• Surrounds nucleus• Made of two layers• Openings allow

material to enter and leave nucleus

Chromosomes

• In nucleus• Contain genetic

information (characteristics)

• Made of DNA

Nucleolus

• Inside nucleus• Contains RNA to build

proteins

Cytoplasm

• Gel-like mixture

• Surrounded by cell membrane

• Holds all the organelles

Endoplasmic Reticulum• Moves materials and

messages around the cell• Smooth type: lacks

ribosomes• Rough type (pictured):

ribosomes embedded in surface

Ribosomes 803

• Each cell contains thousands

• Make proteins• Found on rough

endoplasmic reticulum & floating throughout the cell

Mitochondria

• Produces energy (power house of the cell)

• Controls level of water and other materials in cell

Golgi Bodies 802

• Protein 'packaging plant‘ and secretes (gets rid of waste)

• Move materials out of the cell

Lysosome• Contains digestive

enzymes • Transports undigested

material to cell membrane for removal

• Destorys bacteria and old cell parts

Vacuoles

• Membrane-bound sacs for storage of water and waste

• Help plants maintain shape

Chloroplast

• Found in plant cells• Contains green

chlorophyll• Traps suns energy

and makes food

Cell Parts and FunctionsCiliaShort hair-like projections Used for movementLocation: outside of cell

FlagellaLong whip-like tailUsed for movementLocation: outside of cell

Plant vs. Animal Cell

http://www.cellsalive.com/