1. Cell Structure and Function
Chapter 7
Cell Structure and Function

2. Parts of the Microscope Microscope parts & their functions

3. Copyright Pearson Prentice Hall
7-1 Life Is Cellular
Photo Credit: © Quest/Science Photo Library/Photo Researchers, Inc.
Copyright Pearson Prentice Hall 3

4. The Discovery of the Cell
Early Microscopes
In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material.
Cork looked like thousands of tiny, empty chambers.
Hooke called these chambers “cells.”
Cells are the basic units of life.
Copyright Pearson Prentice Hall 4

5. The Cell Theory
In 1838, Matthias Schleiden concluded that all plants were made of cells.
In 1839, Theodor Schwann stated that all animals were made of cells.
In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells.
These discoveries led to the cell theory.

6. The Cell Theory The cell theory states:
All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.

7. Basic Cell Structures All cells have a cell membrane.
It is a thin, flexible barrier around the cell.
Many cells also have a strong layer around the cell membrane called a cell wall.
Some cells also have a nucleus, a large structure that contains the cell’s genetic material and controls cell activities.
The material inside the cell, not including the nucleus, is called the cytoplasm

8. Cell Types
Biologists divide cells into two categories: eukaryotes and prokaryotes

9. Characteristics of Prokaryotes
Similarities between Prokaryotes and Eukaryotes
Characteristics of Eukaryotes

10. Prokaryotes - smaller and simple than eukaryotes
have cell membranes and cytoplasm
No nucleus
Contain DNA
Contains all bacteria
Examples: E.coli, MRSA, causes Strep Throat

11. Eukaryotes contain nuclei Contain DNA Have cell membrane, cytoplasm
Specialized structures called organelles
Many are large and multicellular organisms
Grouped into either plant cells or animal cells

15. Prokaryotes vs. Eukaryotes SMARTboard

16. Animal Cell Labeling

17. Plant Cell Labeling

18. 7-2 Cell Structures A Comparison of Cells
Structure
Prokaryotic Cell
Eukaryotic Cell
Plants
Animals
Cell membrane
Cell wall
Nucleus
Ribosomes
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Chloroplasts
Cytoskeleton
7-2 Cell Structures
-Organelle – “little organs” in the cell with specialized functions
- Why does a cell compare to a factory? Use page 197 to find out. Write your answer in the space provided.

19. Cell Structure
Cell Type Found In
Function
Extra Info.
Cell Wall

20. Cell Structure Cell Type Found In Function Extra Info. Nucleus
Nucleolus
Nuclear Envelope
Chromosomes
Chromatin

21. Cell Structure
Cell Type Found In
Function
Extra Info.
Vacuoles
Vesicles

22. Cell Structure
Cell Type Found In
Function
Extra Info.
Lysosomes
Cytoskeleton
Microtubule
Microfilament
Centriole

23. Cell Structure
Cell Type Found In
Function
Extra Info.
Ribosomes
Endoplasmic Reticulum (Smooth and Rough)

24. Cell Structure
Cell Type Found In
Function
Extra Info.
Golgi Apparatus

25. Cell Structure
Cell Type Found In
Function
Picture
Extra Info.
Chloroplast
Mitochondria

26. Cell Structure
Cell Type Found In
Function
Extra Info.
Cell Wall
Cell Membrane

27. Page 200-201: Use the picture to create a flow chart of how proteins are made in the cell
Where are proteins assembled?
Where is the synthesis (making) of membrane proteins completed?
How are proteins transported to the golgi apparatus?
What happens to proteins leaving the golgi apparatus?

28. Cell Structure and Function Matching

29. Building Proteins: SMARTboard

30. Cell Membrane Structure
All cells are surrounded, flexible barrier known as the cell membrane. Many cells also produce a strong supporting layer around the membrane known as a cell wall

31. Cell Membrane
Cell membrane is also known as lipid bilayer The cell membrane regulates what enters and leaves the cell and also provides protection and support.

32. Measuring Concentrations
A solution is mixture of two or more substances. The substances dissolved in the solution are called the solutes The concentartion of a solutions is the mass of solute in a given volume, or mass/volume.

33. 7-3 Cell Transport
Passive Transport – movement of molecules across the cell membrane without the use of energy
Examples include:
Diffusion
Facilitated Diffusion
Osmosis

34. Diffusion
Particles in a solution tend to move from an area where they are more concentrated to an area where they are less concentrated.
This process is called diffusion.
When the concentration of the solute is the same throughout a system, the system has reached equilibrium.

36. Osmosis: An example of Facilitated Diffusion
Osmosis is the diffusion of water through a selectively permeable membrane from higher concentration to lower concentration
Water tends to diffuse from a higher concentration to
Lower concentration
Water moves through the cell
Membrane through proteins
Called aquaporins

38. Osmosis
Water tends to diffuse from a highly concentrated region to a less concentrated region.
If you compare two solutions, three terms can be used to describe the concentrations:
hypertonic (“above strength”).
hypotonic (“below strength”).
isotonic (”same strength”)

39. Osmosis
If you place a cell in a hypertonic solution, the the concentration of dissolved materials is greater OUT of the cell, therefore the cell will LOSE water, and will SHRINK
If you place a cell in a hypotonic solution, the concentration of dissolved materials is greater IN the cell, therefore the cell will GAIN water, and will EXPAND
If you place a cell in an isotonic solution, the concentration of dissolved materials is EQUAL in and out of the cell, and NOTHING will happen to the cell

41. Facilitated diffusion
Glucose molecules
Movement of molecules with the help of protein channels in the cell membrane.
Molecules move from higher concentration to lower concentration
Protein channel

42. Active Transport
Sometimes cells move materials in the opposite direction from which the materials would normally move—that is against a concentration difference. This process is known as active transport.
Active transport requires energy.

43. Active Transport Endocytosis and Exocytosis
Endocytosis is the process of taking material into the cell.
Two examples of endocytosis are:
phagocytosis
pinocytosis
During exocytosis, materials are forced out of the cell.

44. Videos
Facilitated Diffusion
Active Transport

45. Solution A
Solution B

46. 7-4 The Diversity of Cellular Life
Unicellular Organisms – organisms with only one cell
include prokaryotes – bacteria
include eukaryotes – some algae, yeast

47. Multicellular organisms – orgnasisms with more than one cell
have cell specialization – each cell has their own role within the organism

48. Levels of Organization
The levels of organization in a multicellular organism are individual cells, tissues, organs and organ systems