1. Cell Structure & Function

2. Cell Theory All living things are made up of cells.
Cells are the smallest working units of all living things.
All cells come from preexisting or other cells through cell division.

3. Definition of Cell
A cell is the smallest unit that is capable of performing life functions.

4. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell
Nerve Cell

5. Prokaryotic 2. Eukaryotic
Two Types of Cells
Prokaryotic Eukaryotic
Can you see what the difference between them is?

6. Prokaryotic
DNA is not in a nucleus, it sort of floats around the cell. No organelles contain membranes.
Few internal structures. No mitochondria, no chloroplasts, no nucleus
One-celled organisms, Example: Bacteria, virus, amoebas

7. Examples of Cells that Move
Bacteria Cells
Notice the bacteria and paramecium have cilium & flagella. Flagella is the tail-like structure and cilia are the hair-like structures. Both help the cell with locomotion or movement of the cell.

8. Eukaryotic Cells Contain organelles surrounded by membranes
Have a true nucleus
Make up most living things.
Plant
Animal

9. Animal and Plant Cells What’s the difference?
Animal cells do not have a cell wall, but they both have a cell membrane.
Plant cells have a cell wall, chloroplasts, and larger vacuoles
Animal cells are found in humans, animals, insects, etc…

10. Cell Parts. . . are called Organelles They are very small in size
They perform all the functions of the cell.
Can only be observed under a microscope
Have specific functions
Found throughout cytoplasm of the cell.

11. Surrounding the Cell

12. Cell Membrane
Flexible outer membrane of the animal cell and found under the cell wall in plants.
Membrane controls movement in and out of the cell
Must move oxygen, wastes, water, and nutrients in and out of the cell.

13. Cell Wall Most commonly found in plant cells & bacteria
Found to be more tough and rigid than the cell membrane
Supports & protects cells
Cell wall allows nutrients and water through the holes in the wall which are called plasmodesmata.

14. Inside the Cell

15. Nucleus Directs cell activities
Separated from cytoplasm by nuclear membrane
Contains genetic material – DNA on chromosomes
Inside the nucleolus is RNA and protein, not much DNA at all.
Typically the largest organelle in the cell.
When chromosomes are bundled together they are called chromatin.

16. Nuclear Membrane Surrounds nucleus Made of two layers
Openings allow material to enter and leave nucleus
Only found in cells with a nucleus. (Eukaryotic)
Pre-Ap only

17. Chromosomes Inside nucleus Made of DNA
DNA contains instructions for traits & characteristics
DNA is made up of 4 nitrogen bases:
1. Adenine 2.Guanine
3. Cytosine 4. Thymine
Pre-Ap only

18. Nucleolus What’s inside the nucleolus.
Appears tightly bundled within the nucleus
Contains DNA & RNA.
RNA is used to build proteins that will carry out many functions of the cell.
Pre-Ap only

19. Cytoplasm
Thick gel-like mixture that fills the cell (light blue below)
Surrounded by cell membrane
80% water that is clear – fills the cell

20. Mitochondria
Produces energy through chemical reactions – breaking down fats & carbohydrates
Controls level of water and other materials in cell
Recycles and decomposes proteins, fats, and carbohydrates
Like the digestive system of the cell.

21. Vacuoles
Sac with a membrane used for storage of food, water, and waste products.
Vacuoles contain water solution
Vacuoles are much larger in plant cells than animal cells.
A drooping plant would indicate empty vacuoles, but a full plant shows the vacuoles are full of water.

22. Chloroplast
Usually found in plant cells, not in animal cells – photosynthesis takes place here.
Contains green fluid called chlorophyll
Chlorophyll uses the sun’s energy to combine Carbon Dioxide (CO2) & Water (H2O) to create sugars. The plant releases the O2 created and uses the sugar to grow.

23. Endoplasmic Reticulum
Also called ER
Looks like a maze
Main function: helps make proteins and other substances
Works with Ribsomes
Usually found around the nucleus

24. Ribosomes Look like dots Main job: make proteins needed by the cell
Is helped by the ER
Can be found attached to the ER or floating in the cell

25. Golgi Apparatus Also called Golgi Bodies Flattened sacs and tubes
Is like a warehouse
Main job: packages and sends out proteins to other organelles or to other cells

26. Lysosomes Sac like structures They are like recycling centers
Main job: break down old cell parts. Break down large food particles into smaller ones