Cell Organelles

Prokaryotes Domain

Bacteria + Archea

Eukaryotes Domain

Protists, Fungi, Plants, Animals

Prokaryote Characteristics

• no nucleus

• DNA in a nucleoid

• Cytosol

• No organelles (other than ribosomes)

• small size

Eukaryote Characteristics

• Nucleus/Nuclear Envelope

• Cytosol

• Membrane-bound organelles

• Larger in size, more complex

Nucleus

• contains genetic material, instructions for producing proteins

• contains DNA in the form of Chromatin

Chromatin

complex of DNA + proteins; makes up chromosomes

What is the Nucleus surrounded by?

Nuclear Envolope, double membrane - continous with the ER

Nuclear Pores

controls what enter/leaves the nucleus

Nucleolus

region where ribosomal subunits are formed

Ribosomes

protein synthesis, composed of rRNA and protein

Free Ribosomes

floating in cytosol, if protein is targeted for intercellular use in the cytosol

Bound Ribosomes

attached to ER, if protein is targeted secretion, membrane fixation, or use in lysosomes

Endomembrane System

regulates protein traffic + performs metabolic functions

Rough ER

ribosomes on surface

Function: puts proteins into vesicles for secretion and sends these transport vesicles to the golgi

Smooth ER

no ribosomes on the surface

Functions:

• synthesizes lipids (ex. cholesterol)

• metabolizes carbohydrates

• detoxes drugs and poison

• stores calcium ions

Golgi Appartus

• synthesis and packaging of small molecules for transport (in vescicles)

• produces lysosomes

• series of flattened sacs

Cis/Trans Face

Cis - recieves vesicles

Trans - ships vesicles

Lysososomes

• intercellular digestion, recycle cells materials, programmed cells death

• contains hydrolytic enzymes

Mitochondria

site of cellular respiration (also has double membrane)

Cristae

• folds of inner membrane

• contains enzymes for ATP production

• has increased surface area for higher ATP made

Matrix

fluid-filled inner compartment

Chloroplasts

site for photosynthesis, has double membrane

What is in the chloroplast?

• thylakoid disks in stacks

• stroma (fluid)

• chlorophylls - for catching sunlight energy

Endosymbiont Theory

• Mitochondria & chloroplasts share similar origin

• Prokaryotic cells engulfed by the ancestors of eukaryotic cells

• Explains the origin of eukaryotic cells

Evidence: 

• Double-membrane structure

  • Have own ribosomes & DNA

  • Reproduce independently within cell

Vacuoles

storage of materials (food, water, minerals, etc.)

membrane bound vesicles

central vaculoes in prokaryotes

Peroxisomes

• break down fatty acids, detox alcohol

• contain catalse to break down hydrogen peroxide

Cytoskeleton

• support, motility, regulate biochemical activities

3 Types of Cytoskeleton Fibers

• microtubules

• microfilaments

• intermediate filaments

Centrosomes

region from which microtubules grow during cell division

Cilia

short, numerous, move fluids

Flagella

long and few, propel through water

What is Cell Wall composed of?

Cellulose

Plasmodesmata

channels between cells to allow passage of molecules

PLANT CELLS ONLY

• one central vacuole

• chloroplasts

• cell walls of cellulose

• plasmodesmata

ANIMAL CELLS ONLY

• many small vacuoles

• centrioles

• desmosones, tight and gap junctions

• ECM

Pili

short, hair-like structures on the cell surface of prokaryotic cells, helps bacteria to bind to body tissues

Plastids

a membrane bound organelle, plays major roles in photosynthesis and storage