Cell Organelles and Functions

Nucleus• Structure

– Contains • Chromatin (DNA)• Nucleolus

– Surrounded by• Nuclear Envelope (w/ pores)

• Function: The Information Center of the Cell

The Nucleus

Chromatin• Structure:

– A thread-like mass of DNA and Protein – Chromatin becomes Chromosome during cell

reproduction

• Function: – contains information for building proteins

(enzymes, channels, cell structural components)

Chromatin

Nucleolus

• Structure: Spherical mass of DNA and RNA

• Functions: Making ribosomes

Nuclear Envelope• Structure: Lipid bilayer that surrounds

the nucleus• Function: Controls what goes in and out

of nucleus; protects DNA

Nuclear Pores• Structure: Protein channels found in the

nuclear envelope• Function: Allows information to go to the

cytoplasm

Ribosomes• Structure: Tiny proteins/RNA • Function: assemble amino acids into

protein strands

Endoplasmic Reticulum• Structure: Membrane network • Function: transport substances

throughout the cell.– Rough

• Ribosomes attached • Transports proteins

– Smooth• No ribosomes attached• Transports fats, etc

Endoplasmic Reticulum

Smooth Rough

Golgi Body• Structure: Flattened disks of membrane• Function: involved with packaging cell

products for export. Can create vesicles

Vesicles (Vacuoles)• Structure: Membrane bound spheres

created by Golgi, ER or Cell Membrane• Function: Store water/wastes/food; some

are involved in delivering things in and out of the cell

Lysosome• Structure: a special type of vesicle• Function: attaches to other organelles

and injects them with digestive enzymes.

Plasma “Cell” MembraneStructure: • Made of phospholipids which are special

fats that have a charge• Also has proteins that act as channels and

binders

Function: • Separates cell contents from the outside• Directs movement of things in and out.

Plasma Membrane

Cytoskeleton (Microtubules)

• Structure: Thin rods and tubes of protein• Function: Serve for internal support and

transport

Cytoplasm

• Structure: An aqueous mixture (called cytosol) that contains everything between the nucleus and membrane

• Function: Most things happen there

Centrosome

• Structure: in animal cells, a paired bundle of protein filaments called CENTRIOLES. Plants don’t have anything at the centrosome.

• Function: directs the growth of cytoskeleton, especially during cell reproduction.

centriole

Mitochondria

Structure: • Bean shaped organelle (has a double

membrane – all the way)

Function: • Site of cellular respiration (process of

getting energy from food)– C6H 12O6 + O2 CO2 + H2O + Energy (ATP)

Mitochondria

Plant Cell Parts

• Cell Wall• Chloroplast• Central Vacuole

Cell Wall

• Structure: Protective outer layer made of cellulose primarily

• Function: provides structural support for plants.

Chloroplast

• Membrane bound organelle which contains the green pigment Chlorophyll, which can convert sunlight into chemical energy.

• Site of Photosynthesis in plants

Central VacuoleStructure: • Large vesicle that takes up much of the

area of the plant cell.

Function: • Digestion occurs here and waste excretion• Provides “turgor pressure” for the cell,

allowing it to stay stiff, not wilted.

The Animal Cell