1. Chapter 7 Cell Structure and Function
7-1 Life is Cellular
7-2 Cell Structure
7-2 The Cell as a Factory
7-3 Movement Through
the Membrane

2. 7-1 Life Is Cellular

3. Interest Grabber
All living things are made up of cells. Some organisms are composed of only one cell. Other organisms are made up of many cells.
1. What are the advantages of a one-celled organism?
2. What are the advantages of an organism that is made up of many cells?

4. 7-1 Vocabulary
Cell-
Collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life.
Cell theory-
idea that all living things are composed of cells and new cells are produced from existing cells.
Cell Membrane-
thin, flexible barrier around a cell; regulates what enters and leaves the cell.

5. 7-1 Vocabulary Cell Wall- Nucleus- Ctyoplasm-
strong layer around the cell membrane in plants, algae, and some bacteria.
Nucleus-
the center of the atom which contains the protons and neutrons; in cells, large structure inside some cells that contains the cell’s genetic material (DNA) and controls the cell’s activities.
Ctyoplasm-
material inside the cell membrane- but not including the nucleus.

6. 7-1 Vocabulary Prokaryote- Eukaryote- Organelle-
single-celled microorganism that lacks a nucleus.
Eukaryote-
organism whose cells contain nuclei
Organelle-
specialized structure that performs important cellular functions within a eukaryotic cell.

7. 7-1 Life is Cellular 1. Cell Theory states three main points
A. All living things are composed of cells.
B. Cells are the basic units of structure and function in living things.
C New cells are produced from existing cells

8. 7-1 Life Is Cellular
2. Prokaryotes and Eukaryotes
A. Cells of Prokaryotes do not have a nucleus, but cells of Eukaryotes do.
B. Prokaryotes: have cell membranes and cytoplasm but do not contain nuclei
All bacteria are prokaryotes

9. 7-1 Life Is Cellular
C. Eukaryotes: do contain nuclei, a cell membrane and cytoplasm, plus organelles (specialized structures that perform important cellular functions)
i. Can be single-celled organisms or large multicellular organisms
ii. All plants, animals, fungi, and many microorganisms are eukaryotes

10. 7-2 Cell Structure

11. 7-2 Cell Structure Division of Labor
A cell is made up of many parts with different functions that work together. Similarly, the parts of a computer work together to carry out different functions.
Working with a partner, answer the following questions.
1. What are some of the different parts of a computer? What are the functions of these computer parts?
2. How do the functions of these computer parts correspond to the functions of certain cell parts?

12. 7-2 Cell Structure Vocabulary
Chromatin-
granular material visible within the nucleus; consists of DNA tightly coiled around proteins.
Chromosome-
threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next.
Nucleolus-
small, dense region within most nuclei in which the assembly of ribosomes begins

13. 7-2 Cell Structure Vocabulary
Nuclear envelope-
double-membrane layer that surrounds the nucleus of a cell.
Cytoskeleton-
network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.
Microtubule-
hollow tube of protein that maintains cell shape and can also serve as a “track” along which organelles are moved.

14. 7-2 Cell Structure Vocabulary
Microfilament-
long, thin fiber that functions in the movement and support of the cell.
Ribosome-
small particle in the cell on which proteins are assembled; made of RNA and protein.
Endoplasmic reticulum-
internal membrane system in cells in which components of the cell membrane are assembled and some proteins are modified.

15. 7-2 Cell Structure Vocabulary
Golgi apparatus-
stack of membranes in the cell in which enzymes attach carbohydrates and lipids to proteins.
Lysosome-
cell organelle filled with enzymes needed to break down certain materials in the cell.
Vacuole-
cell organelle that stores materials such as water, salts, proteins, and carbohydrates.

16. 7-2 Cell Structure Vocabulary
Chloroplast-
organelle found in cells of plants and some other organisms that uses energy from sunlight to make energy-rich food molecules by photosynthesis.
Mitochondrion-
cell organelle that releases energy from stored food molecules.

17. 7-2 Notes Cell Structures
1. Cell Wall
a. In plant cells, but not animal cells
b. Provides support and protection for the cell
C. Made mostly of cellulose: a tough carbohydrate fiber
Animals NO
Plants Yes

18. 7-2 Notes Cell Structures
2. Nucleus
a. Controls most cell processes and contains the hereditary information of DNA
b. Nucleolus
i. A small region where ribosome assembly begins
c. Nuclear Envelope
Double layer membrane with pores that surrounds the nucleus
Pores allow material to move into and out of the nucleus

19. 7-2 Notes Cell Structures
3. Cytoskeleton
a. Made of protein filaments and helps maintain the cell’s shape
b. It also aids in many forms of cell movement
4. Ribosomes
a. Where proteins are made
b. Follow coded instructions from the nucleus

20. 7-2 Notes Cell Structures
5. Endoplasmic Reticululm (ER)
a. Rough ER produces new proteins including membrane proteins
b. Smooth ER: modifies or detoxifies lipids using enzymes
6. Golgi Apparatus
Stack of membranes that receives proteins from the rough ER
Enzymes attach carbohydrates & lipids to proteins

21. 7-2 Notes Cell Structures
7. Chloroplasts
a. Use the energy from the sunlight to make energy-rich food molecules in a process known as photosynthesis
b. Chlorophyll (green pigment) is located in the photosynthetic membranes
8. Mitochondria
Matrix where carbohydrates break down to form CO2 and water
Use energy from food to make high-energy compounds (ATP) that the cell can use to power growth, development, and movement

22. Venn Diagrams Prokaryotes Eukaryotes Animal Cells Plant Cells
Section 7-2
Prokaryotes
Eukaryotes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell membrane
Ribosomes
Cell wall
Animal Cells
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Lysosomes
Go to Section:

23. Figure 7-5 Plant and Animal Cells
Section 7-2
Nuclear
envelope
Ribosome
(attached)
(free)
Smooth endoplasmic
reticulum
Nucleus
Rough endoplasmic reticulum
Nucleolus
Golgi apparatus
Mitochondrian
Cell wall
Cell
Membrane
Chloroplast
Vacuole
Plant Cell
Go to Section:

24. Figure 7-5 Plant and Animal Cells
Section 7-2
Centrioles
Nucleolus
Nucleus
Nuclear
envelope
Rough
endoplasmic
reticulum
Golgi apparatus
Smooth
Mitochondrian
Cell
Membrane
Ribosome
(free)
(attached)
Animal Cell
Go to Section:

25. Figure 7-7 Cytoskeleton Cell membrane Endoplasmic reticulum
Section 7-2
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Michondrion
Go to Section:

26. 7-2 The Cell as a Factory

27. 7-2 The Cell as a Factory 1. The Cell as a Factory
a. One of the most important jobs in the cellular “factory” is making proteins
b. Like a cell, a factory has a control center, support structures, an assembly area, and a power supply
c. A factory needs a transportation system to move parts and machines from one building to another ER

28. 7-2 The Cell as a Factory
d. The control center sends out information and instructions to the rest of the cell, much like an assembly line
i. Ribosomes
ii. DNA
e. Once the product is made, it is sent to get the final details
i. Golgi Apparatus
f. The power supply in the factory fuels all these processes
i. Mitochondria

29. 7-2 The Cell as a Factory Comparing Cells
Yes
Yes No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes No
Small or none
Yes
Yes
Yes No
Yes
Yes
Yes

30. 7-3 Movement Through the Membrane

31. In or Out?
How is a window screen similar to a cell membrane? Read on to find out.
1. What are some things that can pass through a window screen?
2. What are some things that cannot pass through a window screen? Why is it important to keep these things from moving through the screen?
3. The cell is surrounded by a cell membrane, which regulates what enters and leaves the cell. Why is it important to regulate what moves into and out of a cell?

32. 7-3 Movement Through The Membrane Vocabulary
Lipid bilayer-
double-layered sheet that forms the core of nearly all cell membranes
Concentration-
the mass of solute in a given volume of solution, or mass/volume
Diffusion-
process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.

33. 7-3 Movement Through The Membrane Vocabulary
Selective permeability-
property of biological membranes that allows only certain substances to pass through them.
Osmosis-
diffusion of water through a selectively permeable membrane,
Facilitated diffusion-
movement of specific molecules across cell membranes through protein channels
Active transport-
energy-requiring process that moves material across a cell membrane against a concentration difference.

34. 7-3 Movement Through The Membrane
1. Cell Membrane
a. Regulates what enters and leaves the cell
b. Provides protection and support for the cell
c. Lipid bilayer: a double-layered sheet of lipids in the cell membrane
i. Polar molecules are on the outside of the bilayaer
ii. Non-polar parts are on the inside of the bilayer
d. Most membranes contain proteins that run through the bilayer
E. Carbohydrate chains are attached to the protein’s outer surface

35. Figure 7-15 The Structure of the Cell Membrane
Section 7-3
Outside
of cell
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains
Inside
of cell
(cytoplasm)
Go to Section:

36. 7-3 Movement Through The Membrane
2. Diffusion
Diffusion: In a solution, molecules move constantly and try to go from an area of high concentration to an area of low concentrated
No energy is required for diffusion to happen!!

37. 7-3
3. Osmosis
a. Cell membranes (biological membranes) are selectively permeable: some substances can cross and others cannot
b. Osmosis is the diffusion of water through a selectively permeable membrane

38. Figure 7-17 Osmosis Cell membrane Water molecules Higher Concentration
of Water
Cell
membrane
Lower Concentration
of Water
Sugar molecules

39. 7-3 4. Facilitated Diffusion
Protein channels allow certain molecules to diffuse across the membrane but not cross the lipid bilayer
Movement through the channels will only occur if there is a difference in concentrations surrounding the bilayer
Lipid bilayer

40. 7-3
5. Active Transport
a. Sometimes material moves across a membrane against the concentration gradient
b. Active transport: material moving from low concentration to high concentration and requires energy
Molecule to
be carried
Low
Concentration
Cell
Membrane
High
Concentration
Molecule
being carried
Low
Concentration
Cell
Membrane
High
Concentration
Energy
Energy