Organelles

What’s an Organelle?

• A cellular component that performs a

specific function for the cell

• Plant and animal cells share the same

organelles, but plant cells have a few extra

Cell Membrane

• Allows certain

materials in and out of

the cell

• Made up of

phospholipids &

specialized proteins

– Channel Proteins

– Receptor Proteins

– Marker Proteins

• “Flows” around cell

Cytoplasm

• Area inside the cell,

not including the

nucleus, which

contains the

organelles

• Made up of fluid

called cytosol

• Helps give the cell

shape

Nucleus

• Directs most activities of

the cell

• Contains most of the cell’s

genetic info (DNA)

– Tells the ribosomes which

types of proteins to make

• Surrounded by a membrane

called the nuclear envelope

• Chromatin - DNA inside the

cell is connected to protein

• Nucleolus – small, dark area in

the nucleus where ribosomes

are made

Mitochondria

• “Powerhouse” of the cell

– Makes energy for the cell

• Converts the chemical energy stored in food into compounds the cell can use (ATP)

• The more energy a cell needs, the more mitochondria it has

• Made up of 2 membranes (inner & outer) and a matrix

Mitochondria Continued

• Outer membrane covers the mitochondria

• Inner membrane has many folds (called cristae) which increases the surface area

– This provides more space for reactions to occur

• The matrix is all of the fluid contained inside the mitochondria

Endoplasmic Reticulum (ER)

• Serves generally as a

pathway where

molecules that are

produced move from

one part of the cell to

another

• There are 2 types:

Rough ER & Smooth

ER

Rough ER

• Rough ER has bumps

– Bumps are ribosomes

• Site where proteins that are released from the cell and cell membrane proteins are produced

• Collects proteins produced by the attached ribosomes, packages them into vesicles (bubbles), and sends them to the Golgi or to the cell membrane for use

Smooth ER

• Contains NO

ribosomes

• Synthesizes (puts

together/creates)

membrane lipids

• Detoxifies drugs

• Liver cells contain a

large amount of

smooth ER

Ribosomes

• Made up of RNA

molecules

• Creates (synthesizes)

proteins

• Can be found either

floating in the cytoplasm

or attached to the ER

• Nucleus tells the

ribosomes what proteins

to make

Golgi Apparatus

• Made up of a system of membranes

• Packaging and distribution center of the cell

• Puts the “finishing touches” on molecules, such as proteins, and packages them into vesicles

• Finished products can be used inside or outside the cell

Golgi Apparatus cont.

Lysosomes

• Small organelles that

contain enzymes

• These enzymes digest

proteins, carbs, lipids, and

old organelles

• Releases broken down

molecules to other

organelles to be used

Cytoskeleton

• Made up of protein

filaments called

microtubules and

microfilaments

• Helps the cell to

maintain its shape

Centrioles

• Found near the

nucleus

• Help to organize cell

division (how cells

reproduce)

• Not found in plant

cells

Vacuoles

• Large storage organelles

• Plants have large, central vacuoles that help plants support leaves and flowers

• Store enzymes, food, water, & wastes

• Some also contain poisons that plants can use for defense

• Some animal cells and some single-celled organisms also have vacuoles

Cell Wall

• Rigid structure outside

the cell membrane in

PLANTS

• Made of cellulose

• Contains pores which

allow molecules to pass

through

• Helps plants maintain

their shape & structure &

protects the cell

Chloroplasts

• Green organelles which take sunlight, CO2, & H2O and covert them into glucose which the cell can use for energy (photosynthesis)

• chlorophyll is a chemical inside chloroplasts which capture sunlight