1. Biology Unit 4: Cell Structure & Function
               
                  
Plant Cell
Animal Cell
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2. Discovery of Cells 1600’s Robert Hooke 1820’s: Rene Dutrochet
1830’s: Robert Brown
Matthias Schleiden
Theodore Schwann
Rudulph Virchow
Discovery of light microscope
Named box-like structures in cork “cells”
Cells are found in various parts of organisms
All cells have a nucleus
All plants are composed of cells
All animals are composed of cells
All cells come from living cells

3. Cell Theory Three parts: All living things are made of cells
The cell is the basic unit of structure and function in living things
All cells come from existing cells

4. Unicellular Organisms
Cell is the organism
In terms of numbers > dominate life on Earth
Chlamydomonas
Euglena
Yeast
Volvox aureus

5. Multicellular Organisms
Made up of many cells
Great variety of organisms
All depend on specialized cells
Cells develop in different ways to perform different tasks
Ex: Red blood cells transport oxygen throughout body
Red blood cells

6. Multicellular Organisms (cont.) Levels of organization
Cell - Ex: muscle cell
Tissue - group of similar cells perform a particular function
Ex: muscle tissue
Organ - group of tissues that work together
Ex: stomach
Organ system - group of organs that work together to perform specific function
Ex: digestive system

7. Muscle cell
Smooth muscle tissue
Digestive System
Stomach

8. Types of Cells Eukaryotic Prokaryotic
Genetic material contained in nucleus
Plants, animals, fungi and protists
Prokaryotic
Genetic material NOT contained in nucleus (*No nucleus*)
Bacteria

9. The Eukaryotic Cell

10. Cell Structure Like a factory Two major parts: cytoplasm & nucleus
Organelles (“little organs”)
Act like specialized organs
Some structures developed from early prokaryotes
Ex: mitochondria & chloroplasts

11. Cytoplasm
Gelatin-like material inside the cell membrane, outside the nucleus
Contains organelles
Site of most cell activity
Factory floor where products are assembled, finished & shipped

12. Nucleus Nucleus Control center of the cell > boss or CEO
Responsible for overall function of factory
Determines what proteins will be made
Contains hereditary information > DNA

13. Nucleolus Nucleolus Small, dense region of nucleus
Assembly of ribosomes begins here

14. Nuclear Envelope Nuclear envelope Membrane around nucleus only
Has small pores that allow information and ribosomes to move in and out of nucleus
Nuclear envelope

15. Ribosomes Responsible for assembling proteins
Workers on assembly line in factory
Responds to orders from boss > nucleus
Located throughout cytoplasm

16. Endoplasmic Reticulum
Site where lipid components of cell membrane are assembled
Also assembles proteins exported from cell
Assembly line in factory
Two types:
Rough ER - appears bumpy due to ribosomes on surface
Smooth ER - No ribosomes

17. Endoplasmic Reticulum

18. Golgi Apparatus
Prepares proteins and other materials for storage or use outside cell
Like finishing & packing department in factory
Finishing touches put on before ready to leave factory
Sorted & stored or shipped outside of cell

19. Lysosomes Small organelles filled with enzymes
Maintenance crew for factory
Break down carbs, lipids & proteins for use by cell
Remove “junk” - waste and dead material found in cell

20. Vacuoles Saclike structures that store nutrients
water, salts, proteins & carbs
Storage rooms of factory

21. Mitochondria Convert nutrients in food into energy for cell use
Local power plant for factory
Source of energy

22. Chloroplasts
Capture energy from sunlight and convert it into chemical energy > photosynthesis
Solar power source for factory
Only in plant cells
Chlorophyll > chemical that causes plant cells to be green

23. Cytoskeleton
Network of protein fibers that helps cell maintain its shape
Microtubules and microfilaments
Support structure of factory (beams & columns that support walls & roof)
Also used to move cell membrane

24. Cell Membrane Phospholipid bilayer
Regulates what enters & leaves the cell
Like gate into the factory
Provides protection & support
Gives the cell its shape

25. Present in plants, algae, fungi and many prokaryotes
Cell Wall
Outside cell membrane
Provides protection & support
Present in plants, algae, fungi and many prokaryotes
Never in animal cells
Plant Cell

26. Cell Wall (algae)

27. Cell Wall (bacteria > prokaryote)

28. Movement Across Cell Boundaries

29. Diffusion Molecules spread into available space
across membrane
from area of higher concentration to area of lower concentration
without use of energy > passive transport
Equilibrium - when concentration is same throughout a system

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31. Osmosis Diffusion of water through a selectively permeable membrane
Membrane allows only certain substances to pass through
Type of diffusion - does not require use of energy > passive transport

32. How Osmosis Works Isotonic - “same strength”
Same concentration on both sides
Hypertonic - “above strength”
Higher concentration outside cell
Water leaves, cells shrink
Hypotonic - “below strength”
Lower concentration outside cell
Water comes in, cells swell

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34. Facilitated Diffusion
Movement of specific molecules across membranes through transport proteins
Could not cross without them
Does not require use of energy > passive transport

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36. Active Transport Cells move materials in direction opposite diffusion
Against concentration difference (gradient)
Requires energy
Small molecules or ions (K, Ca, Na) carried by transport proteins or “pumps” in membrane

38. Active Transport (cont.)
Larger molecules & clumps of material transported by:
Endocytosis - movement of materials into cell through vesicles (pockets) of cell membrane
Phagocytosis- “cell eating”
Pinocytosis- “cell drinking”
Exocytosis - movement of materials out of cell through vesicles

40. IV. Homeostasis The Cell as an Organism
Unicellular organism- organism made up of only one cell
Examples:
Bacteria
Yeast
protists- amoeba, diatoms, plasmodium
b. Exhibit all 8 features of living things

41. c. All organisms must maintain homeostasis
Defined- relatively constant internal; physical and chemical conditions

42. B. Multicellular Life
1. Cells in multicellular organisms do not live on their own
2. They are interdependent- need to work together

43. 3. Need to communicate- send and receive signals with each other

44. 4. Cell specialization- different types of cells play different roles
Some move- throat lining cells
Some react- nerve cells
Some produce substances- glandular cells

45. 5. Levels of Organization cells --> tissues --> organs --> organ systems --> organisms
a. Tissue – is a group of similar cells that work together to perform a function.

46. Examples of Tissues
Nerve Tissue
Nerve Cell

47. b. Organ – is a group of tissues that work together to do a job.

48. c. Organ system- is a group of organs that work together to do a certain job.

49. Examples of organisms Crow Human Amoeba Elephant Bonobo
d. Organism – is a living thing that can be made of one or more cells.
Crow
Human
Amoeba
Elephant
Bonobo

50. 6. Cellular Communication
Cells in large organisms communicate by means of chemical signals
The signals can either speed up or slow down an activity of the cells that are receiving them
Cellular junctions- hold cells together in tight formations that allow for quick signaling
Ex: neuromuscular junction

51. d. Receptor- can be found on or in a cell; a specific protein whose shape fits that of a molecular messenger
Ex: Hormones
Thyroid Hormone Receptor
Thyroid gland is controlled chemically by the pituitary- function: metabolism

52. Careers that study cells and/or tissues
Histologist- tissues/cells
Pathologist- infected tissues/cells
Oncologist- cancer cells
Embryologist- examines infertility
Geneticist
Veterinarian