1. Structures of the Cell

2. Standard SB1a.
Explain the role of cell organelles for both prokaryotic and eukaryotic cells, including the cell membrane, in maintaining homeostasis and cell reproduction.

3. CELL THEORY CELL TIMELINE
Proposed in 1838 by Schleiden & Schwann
All life forms are made from one or more cells.
Cells only arise from pre-existing cells.
The cell is the smallest form of life.
CELL TIMELINE

4. PROKARYOTIC CELLS NO NUCLEUS Small, simple
A prokaryotic cell is enclosed by a plasma membrane and is usually encased in a rigid cell wall
The cell wall may be covered by a sticky capsule
Inside the cell are its DNA and other parts
Grow & reproduce
EX. E. coli (bacterial cells)

5. EUKARYOTIC CELLS HAVE A NUCLEUS & MEMBRANE-BOUND ORGANELLES
Grow & reproduce
Some live as single cells (mostly multicellular)
Examples: Plants, animals, fungi, etc.

6. Cell Parts Organelles –cell structures with specialized functions
Plasma Membrane (cell membrane)- organelle that regulates what comes in and out of the cell, provides protection, and support.
Structure: phospholipid Bilayer

7. Cytoplasm Cytoplasm- in between cell membrane and nucleus
Holds organelles in place
“jello with fruit in it”

8. Nucleus (center of the cell)
Nucleus- center of the cell, contains nucleic acid (DNA)
Include nucleolus which make ribosomes.
Function – Directs cell activites.
Eukaryotes- (animals, plants) have a nucleus and membrane bound organelles
Prokaryotes- (bacteria) have neither

9. Ribosomes
Not bound by a membrane. Found on endoplasmic retituclum and free floating.
Function: Make protein.

10. Mitochondria Mitochondria- rod-shaped
Function: “powerhouse” of the cell
Produces energy from sugar through cellular respiration.

11. Chloroplasts Found in plant cells. Contains green chlorophyll
Function: Photosynthesis uses sunlight to make sugar for plant.

12. Golgi Apparatus Made of 5-8 flattened sacs
Function – processes and packages proteins and lipids.
Move materials within the cell using transport vesicles.

13. Endoplasmic Reticulum (ER)
Structure: series of tubes and sacs.
-Smooth ER (w/o ribosomes) : makes and transports lipids and carbohydrates
-Rough ER (w/ ribosomes): contains, ribosomes to make and transport proteins.

14. Lysosome Type of vesicle
Function - break down materials, digest excess or worn out organelles.
None in plants

15. Vacuoles Large in plant cells, small in animal cells.
Store materials (food, water, etc)

16. Cell Wall Cell wall- surrounds cell membrane only in plants
Made out of cellulose (starch)
Function: Adds extra support

17. Cytoskeleton Frame work of the cell (in the cytoplasm)
Made of microfilaments, a protein matrix

18. Cells Overview