3.2: Organelles

What is an organelle?

Organelles are structures specialized to perform distinct

processes within a cell.

Where are organelles found?Organelles are found in the

cytoplasm of Eukaryotic cells…plant and animal cells.

Nucleus• Brain of the cell• Stores all genetic

information• Must protect DNA and

have it ready for cell to use

• Enclosed by a nuclear membrane

• Contains nucleolus-place where ribosomes are made

Endoplasmic Reticulum• 2 types:– Smooth– Rough

o Smooth ER makes lipids and provides a variety of specialized functions

o Rough ER is covered with ribosomes. Proteins made in the ribosomes enter the rough ER and are modified for stability

Endoplasmic Reticulum

Ribosomes• Link amino acids

to form proteins• Site of protein

synthesis

Golgi Apparatus

• Processes, sorts and delivers proteins• Post Office of the

cell

Vesicles• Sac that divides some material

from the rest of the cytoplasm and transports them from place to place

Mitochondria• Powerhouse of the cell• Supplies energy to the

cell• Bean shaped• Made of two membranes– Inner membrane is place

where food is converted into energy

Vacuole•Storage site for cells

Lysosome• Contain enzymes• Defend cell from

invading bacteria and viruses

• Breaks down damaged or worn out cell parts

• Animal cell only

Centriole• Cylinder shape• Made of short

microtubules• 2 centrioles

perpendicular to one another

• Play role in cell division• Organize microtubules to

form cilia and flagella• Animal cell only

Chloroplast• Carry out

photosynthesis• Convert solar energy

into chemical energy• Contain chlorophyll

which makes plants green• Plants only

Central Vacuole• Large sac filled

with fluid that strengthens and helps support the cell• Prevents plant

from wilting• Plants only

Cell Wall• Surrounds cell

membrane• Rigid layer that

protects, supports and shapes the cell