1. Cell Structures and Functions
Guided Notes – Part 2

2. What you should already know…
A prokaryotic cell is a cell that does not have a nucleus, such as bacteria and archaea.
Prokaryotes are single-celled organisms that do not have a nucleus or membrane-bound organelles.

3. What you should already know…
A eukaryotic cell is a cell that contains a nucleus, such as plant and animal cells.
Eukaryotes are organisms made of eukaryotic cells.
Eukaryotes can be single-celled, but many are multicellular.

4. Bacteria The most common prokaryotes, and the smallest cells known.
Bacteria have
ribosomes
web-like cell wall
cell membrane
long, circular DNA
flagellum (for movement)

5. Eukaryotic Cells
Plant cells and animal cells are two types of eukaryotic cells.
They have many cell parts in common, but also have cell parts that are different.

6. Eukaryotic Cells
A eukaryotic cell has many parts that perform functions to help the cell stay alive.
-cell membrane -cell wall
-cytoskeleton -nucleus
-ribosomes -mitochondria
-endoplasmic reticulum -chloroplasts
-Golgi complex
-cell compartments (vesicles, lysosomes, vacuoles)

7. Cell Membrane
All cells have a cell membrane, a protective barrier that encloses a cell.
It separates the cell’s contents from the cell’s environment.
The cell’s membrane contains proteins, lipids, and two layers of phospholipids.

8. Cell Wall A rigid structure that gives support to a cell.
Plants and algae have cell walls made of cellulose.
Fungi, including yeasts and mushrooms, also have cell walls made of chitin.
Prokaryotic cells have cell walls, but they are different from plants and fungi.

9. Cytoskeleton
A web of proteins in the cytoplasm, that acts as both a muscle and skeleton.
It keeps the cell’s membranes from collapsing.
Made of protein, and helps some cells move

10. Nucleus
A large organelle in eukaryotic cells that contains the cell’s DNA, or genetic material.
DNA contains the information on how to make proteins, which control the chemical reactions and provide structural support for cells and tissues.
The nucleus is covered by two membranes.

11. Ribosomes Organelles that make proteins.
The most abundant and the smallest of all organelles.
All cells need proteins to live.
Proteins are made of amino acids.

12. Endoplasmic Reticulum
A system of folded membranes in which proteins, lipids, and other materials are made.
The ER is part of the internal delivery system of the cell where substances move through the ER to different places in the cell.
ER is either smooth or rough.
Rough ER is covered by ribosomes, which make proteins.
Smooth ER makes lipids and breaks down toxic materials that could damage the cell.

13. Mitochondria
Organelles in which sugar is broken down to produce energy.
Energy released by mitochondria is stored in a substance called ATP, which the cell then uses to do work.
Mitochondria are covered by two membranes.

14. Chloroplasts
Organelles in plant and algae cells in which photosynthesis takes place, the process by which plants and algae make their own food.
Chloroplasts are green because they contain chlorophyll.

15. Golgi Complex The organelle that packages and sends out proteins.
Looks like the smooth ER.
Lipids and proteins from the ER are delivered to the Golgi complex, where they may be modified to do different jobs.
The final products are enclosed in a piece of the Golgi complex’s membrane, that pinches off and then transports to other parts of the cell or out of the cell.

16. Cell Compartments - Vesicles
Vesicles are small sacs that surround materials to be moved into, within, or out of the cell.
All eukaryotic cells have vesicles.

17. Cell Compartments - Lysosomes
Lysosomes are vesicles that are responsible for digestion inside a cell.
They contain digestive enzymes that destroy worn-out or damaged organelles, get rid of waste materials, and protect the cell from foreign invaders.

18. Cell Compartments - Vacuoles
In plant and fungal cells, some vacuoles act like lysosomes.
The large central vacuole in plant cells stores water and other liquids.
Animal cells have small vacuoles that aid in digestion and the release of waste products.

19. Organization of Living Things

20. Tissues
A tissue is a group of cells that work together to perform a specific job.
Example – cardiac muscle tissue
Animals have four basic types of tissues:
nerve tissue
muscle tissue
connective tissue
protective tissue

21. Organs
A structure that is made of two or more tissues working together to perform a specific function.
Examples – heart, stomach, intestines, brain.

22. Organ Systems
A group of organs working together to perform a particular function.
Each organ system has a specific job to do in the body.
Example – digestive system
Plants also have organ systems – leaf systems, root systems, and stem systems.

23. Organisms Anything that can perform life processes by itself.
They can be either unicellular or multicellular.
Organ systems work together to form organisms.

24. Review Choose 4 cell structures and describe the function for each.
Describe 3 ways in which plant cells differ from animal cells.
Explain why every cell needs ribosomes.
Identify the levels of organization in living things.