1. Cell Structure & Function
Chapter 7
Cell Structure & Function

2. 7.1 Life is Cellular Discovery of the Cell
Use of microscopes to discover cells – 1600s
Hooke
looked at cork (plant material used in wine bottle stoppers)
saw small chambers – “cells”
Anton van Leeuwenhoek (Lee-when-hook)
Looked at pond water
saw small organisms

3. 7.1 Life is Cellular Cell Theory All living things are made of cells
Cells are the basic units of life
New cells are made from existing cells

4. 7.1 Life is Cellular Basic Cell Info Many shapes & sizes Size:
Typical 5-50 μm
Small 0.2 μm
Large 1,000 μm
Cell membrane
DNA
2 types:
Prokaryotes & Eukaryotes
(pro-carry-oats) (you-carry-oats)

5. 7.1 Life is Cellular Prokaryotes Eukaryotes Do not have a nucleus
DNA circular
Simple structures
Unicellular
Probably original form of life
Bacteria
Eukaryotes
Has a nucleus that contains DNA
DNA linear
Has more complicated/sophisticated structures
Uni- or multicellular
Probably evolved from prokaryotes
Plants, animals, fungi, protists

6. 7.1 Life is Cellular

7. 7.2 Eukaryotic Cell Structure
Cells are like factories
2 major parts
Nucleus
Cytoplasm
Organelles – “little organs”

8. 7.2 Eukaryotic Cell Structure
Nucleus – control center/main office
Double layer nuclear envelope
Nuclear pores
Where DNA is located
Uncoiled – chromatin
Coiled – chromosome
Nucleolis (most)
Make ribosomes

9. 7.2 Eukaryotic Cell Structure
Ribosomes – assembly line
Small particles of RNA & protein
Follow instructions from DNA on how to make/assemble proteins

10. 7.2 Eukaryotic Cell Structure
Endoplasmic Reticulum – packaging
Lipids of membranes are made
Proteins & other materials are exported from the cell
Smooth ER
Ribosomes not attached
Enzymes that detoxify & make lipids
Rough ER
Export proteins
Ribosomes are attached

12. 7.2 Eukaryotic Cell Structure
Golgi Apparatus – customization shop
Modify, sort & package proteins or other material to be stored or exported

13. 7.2 Eukaryotic Cell Structure
Lysosomes - custodian
Filled w/ enzymes
Breakdown macromolecules into useful pieces
Recycle materials from old organelles
Clean up wastes

14. 7.2 Eukaryotic Cell Structure
Vacuoles - storage
Sacs
All plant cells store water
Used for strength of support structures
Some unicellular/animal cells
Contractile vacuole – controls amt. water in the cell typically in cells surrounded by water

16. 7.2 Eukaryotic Cell Structure
Mitochondria/Chloroplasts - electricity
Mitochondria
In plants & animals
Convert chem eng into ATP
2 membranes
Inner folded up
All come from Mom!

17. 7.2 Eukaryotic Cell Structure
Mitochondria/Chloroplasts - electricity
Chloroplasts – like solar panels
In plants & other photosynthetic orgs
Convert light eng into ATP
2 membranes
Contain chlorophyll

18. 7.2 Eukaryotic Cell Structure
Mitochondria/Chloroplasts – electricity
Theory
Have own DNA
Thought that they were “eaten” by another cell and became an organelle inside

19. 7.2 Eukaryotic Cell Structure
Cytoskeleton – building & transportation
Protein filaments (fibers) give cell its shape
Microfilaments
Made of protein threads called actin
Help cells crawl
Microtubules
Hollow
Used in cell division
Help cells swim
Cilia (ex in trachea)
Flagella (ex sperm)

20. Structure & Function Review
Picture
Structure
Function
Nucleus
Store genetic information
Nucleolus
Make ribosomes
Ribosomes
Make proteins
Endoplasmic Reticulum
Make lipids

21. Structure & Function Review
Picture
Structure
Function
Golgi Apparatus
Ready materials to leave cell
Lysosomes
Clean up wastes and bad organelles
Vacuoles
Store material (usually H2O)
Mitochondria & Chloroplasts
Convert energy to ATP
Cytoskeleton
Structure/support

22. 7.3 Cell Boundaries Cell Membrane Lipid bilayer Flexible Regulation
Hydrophobic
& hydrophilic ends
Flexible
Regulation
Selectively permeable
Support
Protection

23. 7.3 Cell Boundaries Cell membrane Proteins & carbs. “Fluid mosaic”
Transport – pumps & channels
Identification
“Fluid mosaic”

24. 7.3 Cell Boundaries Cell Wall
Plants & other orgs in watery env. or that require rigidity
Made of carbs & proteins
Cellulose
E. coli
Porous

25. 7.3 Cell Boundaries Diffusion through membranes Cytoplasm
Mostly H2O with solutes
Concentration: solute/solvent or mass/volume
Diffusion (pg 182)
Transport of material from one side of a membrane to another
Equilibrium
Osmosis
Diffusion of H2O

27. 7.3 Cell Boundaries
Osmosis
Isotonic
Hypertonic
Hypotonic

28. 7.3 Cell Boundaries Osmotic pressure Balance intake of & water loss
How do conc of solutes change osmosis?
Fun fact: Pure H2O will kill you! Why?
Vacuoles!

29. 7.3 Cell Boundaries Passive vs active transport Active transport
Moving molecules against the concentration gradient
Na+, K+, Ca+ commonly transported through pumps

30. 7.3 Cell Boundaries

32. Movies! Cell membrane Fluid mosaic Passive transport Active transport
Endocytosis
Phagocytosis (cell eating)
Pinocytosis (cell drinking)
Exocytosis (cell excreting)
Hypertonic solution w/ onion cells

33. Biology Chapter 7 Review
7.1 Life is Cellular – pg
Discovery of the Cell
Hooke
Cork
Hollow, empty chambers
“cells” – tiny rooms like in a dorm
Note lab
Van Leewenhoek
Pond water
Small organisms
Cell Theory
All living things are composed of cells
All cells are the basic unit of living things
New cells are produced from existing cells

34. Biology Chapter 7 Review
7.1 Life is Cellular – pg
Discovery of the Cell
Prokaryotes
Simple & small
No nucleus or organelles (except ribosomes)
DNA circular
Single celled organisms only
Eukaryotes
Larger & more complex
Nucleus and organelles present
DNA in long strands
Single or multicellular organisms

35. Biology Chapter 7 Review
7.2 Eukaryotic Cell Structure – pg
Organelles structure & function
Cytoplasm
Nucleus
Nuclear envelope
Chromatin
Chromosomes
Nucleolus
Ribosomes ER
Smooth
Rough

36. Biology Chapter 7 Review
7.2 Eukaryotic Cell Structure – pg
Organelles structure & function
Golgi Apparatus
Lysosome
Vacuole
Mitochondria
Chloroplasts
Cytoskeleton
Note centrioles for coming chapters

37. Biology Chapter 7 Review
7.3 Cell Boundaries – pg
Cell Membrane
Lipid bilayer
Hydrophilic & hydrophobic ends
Proteins
Carbohydrates
Fluid mosaic
Cell Wall
Cellulose
Support/protect cell

38. Biology Chapter 7 Review
7.3 Cell Boundaries – pg
Diffusion
Concentration
Equilibrium
Concentration gradient
Osmosis
How/why water moves
Hypotonic
Isotonic
Hypertonic
Effect on cell

39. Biology Chapter 7 Review
7.3 Cell Boundaries – pg
Facilitated Diffusion
Protein channels
Move in either direction
Direction determined by concentration gradient
Active Transport
Requires energy
Molecular transport
Endocytosis & exocytosis
Phagocytosis
Pinocytosis