1. Cell Structure and Function
Life
Science

2. Two Categories of Cells:
Prokaryotes:
Small and simple cells
Do NOT contain a nucleus
Do NOT contain organelles
All bacteria are prokaryotes
Eukaryotes:
Large and complex cells
Contain a nucleus
Contain organelles
Animals, plants, fungi, etc.

3. Cell Structures

4. Prokaryotic Cell

5. Plant Cell

6. Animal Cell

7. Don’t forget that all cells have all these things!!!
Cell membrane
Cytoplasm
Genetic material (almost all contain DNA)
Have ribosomes, sites of protein synthesis (dehydration synthesis happens here!)

8. Cell Membrane Structure: Functions
Phospholipid bilayer with proteins and carbohydrates
Functions
Thin, flexible barrier
Separates cell from surroundings
Regulates molecules into/out of cell (food, water, wastes, etc.)
Selectively Permeable

9. Cell Wall
Structure:
Made of cellulose (a carbohydrate) and proteins
Rigid wall outside of cell membrane
Only in plants
Function:
Support and protect
Allows water, oxygen, carbon dioxide and other substances to pass through
* Found only in plant, fungi, and algae cells, NOT in animals

10. Nucleus Function: Components (Structure)
Stores DNA (chromatin), hereditary info for cell
Controls cell activities
Components (Structure)
Nuclear Envelope: bilayer lipid membrane that surrounds nucleus and has pores or holes to allow materials to move in/out of nucleus
Nucleolus: Small dense region that makes ribosomes

11. Cytoskeleton Structure: Function:
Network of long protein strands called microfilaments and microtubules
Function:
Microtubules: movement inside cells
Microfilaments: Maintain shape and size of cell

12. Ribosomes Structure: Function: Most numerous organelle
Made of RNA and protein
Function:
Synthesis of Proteins (make proteins)

13. Endoplasmic Reticulum (ER)
Structure:
Internal membrane system
Stacks of flattened sacs
Rough: has ribosomes- gives a bumpy appearance
Smooth: no ribosomes- looks smooth
Function:
Intracellular highway—moves molecules around the cell
Rough: prepares and sends proteins to Golgi for export
Smooth: synthesizes lipids and cell membrane parts, detox (breaks down drugs and toxins)

14. Golgi Apparatus Structure: Function: Stacks of flattened membranes
Processing, packaging, and secreting proteins
Send proteins to their final destinations
Works with Rough ER

15. Lysosome Structure: Function: Small sac which contains enzymes
Not in plants
Function:
Breaks down food: digest proteins, carbs, and lipids, DNA or RNA in cell
Removes debris: digests old organelle or viruses and bacteria

16. Vacuole Structure: Function:
Large sac filled with enzymes, water, and wastes
In plants: VERY large – takes up most of cell
In animals: small – store extra materials
Function:
Storage
Vesicles: small vacuoles involved in transporting substances within cells

17. Centrioles Paired cylindrical organelles near the nucleus Structure:
composed of bundles of microtubules at right angles to each other
Function:
involved in cell division

18. Chloroplast Structure: Function:
Saclike structure that contains chlorophyll (a green pigment)
Function:
Photosynthesis: Changes sunlight energy to organic chemicals (sugars)
Found in plants, algae, and some bacteria
NOT found in animals

19. Mitochondria Structure: Function: Has 2 membranes
Cristae: folds of the inner membrane—increases surface area
Function:
“Powerhouse” of the cell
Cellular Respiration: releases energy from food molecules to power cell (growth, movement, development, etc.)

20. Organelle DNA
Chloroplasts and mitochondria contain some of their own genetic information or DNA
Lynn Margulis – scientist who suggested that mitochondria and chloroplasts are actually descendants of ancient prokaryotes
Endosymbiotic Theory – eukaryotic cells formed from a symbiosis among several different prokaryotic organisms

21. A Cell Is Like A City As a pair, match each structure with the city part that has the same function. Write 1-2 sentences for each structure to explain why you have made this analogy.
Cell Membrane – ?
Cell Wall – ?
Nucleus – ?
Ribosome – ?
ER – ?
Golgi Apparatus – ?
Lysosome – ?
Vacuole – ?
Chloroplast – ?
Mitochondrion – ?
trucking company
power plant
recycling center
storage company
fence surrounding city
post office
factory
border patrol
city hall
restaurant

22. A Cell Is Like A City Cell Membrane – Cell Wall – Nucleus – Ribosome –
ER –
Golgi Apparatus –
Lysosome –
Vacuole –
Chloroplast –
Mitochondrion –
border patrol
fence surrounding the city
city hall
factory
trucking company
post office
recycling center
storage company
restaurant
power plant