Notes 3-2: Looking Inside Cells

Cells have a job!

• Your cells have many jobs to do.• The main job of the cell is to make proteins,

which will be used in all of your body’s major activities.

• Your cells could not do this without the help of it’s organelles.

• Organelles are small structures within the cells that carry out specific functions.

• Let’s talk about all of the different organelles of the cell!

Cell Wall

• Only in plants and some bacteria• Rigid structure on outside of cell made up of

cellulose• Provides protection, support, and shape to

cell• NOT in animal cells! (we have a cytoskeleton

inside our cells instead that provides our cells with a shape)

Plant Cell

Don’t Draw…Notice the location of the cell wall and the cell membrane inside it.

Cell Membrane

• In plants (inside cell wall) and animals (outer layer)

• Controls what comes in and out of cell• Helps provide shape and protection of cell

Animal cell

Don’t Draw…Notice the

location of the cell membrane. Is there a cell wall?

NO!!

Nucleus• The nucleus is the cell’s control center,

directing all of the cell’s activities.•Nuclear Envelope: Protects Nucleus, has pores to control what comes in/out of nucleus•Chromatin: Genetic material of cell (DNA), provides instructions to cells to carry out specific functions•Nucleolus: makes the ribosomes (which make the proteins)

Cytoplasm

• Gel-like fluid within cell• Contains most of cells major organelles

Mitochondrion

• Mitochondria are known as the “powerhouses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.

Endoplasmic Reticulum (ER)• The endoplasmic reticulum is similar to the

system of hallways in a building. Proteins and other materials move throughout the cell by way of the ER. The spots on this organelle are ribosomes, which produce proteins.

•The job of the ER is to modify (change) the proteins.

Ribosomes

• Located on the ER and throughout the cytoplasm

• Site where proteins are made

Golgi Body

• Receive proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell or out of the cell.

Lysosomes

• Small round stuctures• Clean up crew of cell• Contains chemicals to

break down old cell organelles and release them to be used again

Vacuoles

• Storage area for cells• Store food, waste,

and other materials• Some animal cells

have small storage vacuoles

• Only plant cells have one large vacuole called a “central vacuole”

ANIMAL CELL

PLANT CELL

Notice the size difference in the vacuoles between the 2 cells

Chloroplasts

• Only in plant cells• Green organelles in

cytoplasm• Capture energy from

sun to make food for plants (photosynthesis)

• Make the leaves green

Cells are specialized

• Cells have different structures (like shape) to perform a variety of functions

• Not all cells look the same or do the same task

Nerve cells have long extensions to carry signals throughout body. Can you see the nucleus?

Red blood cells are flat so they can carry oxygen through blood vessels. White blood cells are more round and hold chemicals to fight infections.

Let’s Review!

• Do animal cells have cell walls?

• What is the function of the mitochondria?

No!Provide energy to the cell.

Let’s Review!

• Where is the cells DNA located?

• What types of cells have chloroplasts?

In the nucleusPlant cells

Let’s Review!

• What is the main goal of the cell? (What is the cell producing?)

• What is the function of the ribosomes?

ProteinsIt’s the site where proteins are made