1. Section 2: Looking Inside Cells
7.1.b Students know the characteristics that distinguish plant cells, including chloroplasts and cell walls.
7.1.c Students know that the nucleus is the repository for genetic information in plant and animal cells.

2. Enter the Cell Organelles- carry out specific functions within a cell
Cell Wall- a stiff wall that surrounds the membrane giving the cell a rigid boxlike shape
Key concept: “The cell wall helps to protect and support the cell.”
In plants the cell wall is made of cellulose
Cell wall is tough but some things can pass through like water and oxygen
Animal cells DO NOT have cell walls

3. Enter the Cell
Animal cells have cytoskeleton- a protein “framework” inside the cell that gives the cell its shape
Cell Membrane- forms a protective barrier between the cytoplasm and the environment outside the cell because an animal cell does not have a cell wall
ALL cells have cell membranes
Key concept: “The cell membrane controls what substances come into and out of a cell.”
To survive a cell must get food, oxygen, and as well as let out waste (like a window screen)

4. Plant Cells

5. Animal Cell

6. Sail on to the Nucleus
Nucleus is surrounded by the nuclear envelope to protect the nucleus
Chromatin- thin strands floating in the cell that contains genetic material, instructions for directing the cells functions
Nucleolus- where ribosomes are made

7. Nucleus
Key concept: “The nucleus is the cell’s control center, directing all of the cell’s activities.”

8. Organelles in the Cytoplasm
Cytoplasm- a gel-like fluid that many different organelles are found in
Fluid in the cytoplasm is constantly moving
Key concept: “In the cytoplasm are many organelles, including mitochondria, endoplasmic reticulum, ribosomes, Golgi bodies, chloroplasts, vacuoles, and lysosomes. Each of these organelles has specific functions in the cell.”

9. Organelles in the Cytoplasm
Endoplasmic Reticulum
Mitochondria are known as the “powerhouses” of the cell
They convert energy in food molecules to energy the cell can use to carry out its functions
Endoplasmic Reticulum is similar to the system of hallways in a building.
Proteins and other materials move throughout the cell using the endoplasmic reticulum.
The spots on this organelle are ribosomes, which produce proteins.
Mitochondria

10. Organelles in the Cytoplasm
Golgi Body- receive proteins and other newly formed materials from the endoplasmic reticulum, package, and distribute them to other parts of the cell.
Called the cells mailroom
Flattened sacs and tubes
Golgi Body
Chloroplasts- capture energy from the sunlight and use it to produce food for the cell
Only in plant cells (and some other organisms)
They are green in color giving the plant a green color
Plant cells

11. Organelles in the Cytoplasm
Vacuole- stores water, food, waste, and other materials
some animal cells have vacuoles that store food, water, waste, and other materials
large water filled sacks
most plant cells have one
Ribosomes- small structures that function like factories to produce proteins
they may float in the cytoplasm or be attached to the endoplasmic reticulum

12. Organelles in the Cytoplasm
Lysosomes- small organelles that contain chemicals that breaks down food particles and worn-out cell parts
small round structures
the “clean-up crew”

13. Cell Diversity
Nerve Cell
Blood Cell
Key Concept: “The variety of structure in cells reflects differences in cell function.”
Some cells have certain organelles but not others
Some cells have more of one type of organelles
Cells come in different shapes

14. Looking Back
What role do the cell wall and cell membrane play in the cell?
What is the role of the nucleus in the cell?
What organelles are found in the cytoplasm and what are their functions?
How do cells differ?