Biology I Chapter 7
Interest Grabber
NOTEBOOK #1
Are All Cells Alike?
• 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 onecelled organism? • 2. What are the advantages of an organism that is made up of many cells?
• There are several scientists that are responsible for Discovery of the Cell understanding the cell. They are:
1. Robert Hooke - Observed a piece of cork and saw thousands of empty spaces. Coined the “cell” because they reminded him of the small rooms in the monastery. 2. Anton van Leeuwenhoek - first person to observe living cells. 3. Matthias Schleiden - All plants are made of cells. 4. Theodor Schwann - All animals are made of cells. 5. Rudolf Virchow - New cells come only from other cells.
The Cell Theory 1.All living things are composed of cells. 2.Cells are the basic units of structure and function in living things. 3.New cells are produced from existing cells.
Microscopes
• Compound light microscope - uses two lenses to focus on an image through which light passes through. • Transmission Electron Microscope (TEM) sends a beam of electrons through a microscopic slice of a specimen. • Scanning Electron Microscope (SEM) - sends a beam of electrons over the surface of an object to produce a 3-D image.
Prokaryotes • They are cells that have genetic material that is not contained in a nucleus. • Example - bacteria
Eukaryotes • Usually larger and more complicated than prokaryote cells. • Contain a nucleus in which their genetic material is separated from the rest of the cell. • Contain dozens of structures and internal membranes.
Prokaryotic and Cell membrane
Cytoplasm
Prokaryotic Cell Cell membrane Cytoplasm Nucleus
Eukaryotic Cell Organelles
NOTEBOOK #2
1. What were the following scientists credited with: • Hooke, Leeewenhoek, Schleiden, Schwann, Virchow 2. What are the three kinds of microscopes? 3. What is a prokaryote? 4. What is a eukaryote?
NOTEBOOK #3
Interest Grabber
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?
Comparing the Cell to a Factory • The cell is made up of many tiny structures that act similar to specialized organs. • The structures are known as organelles. • Biologist split the eukaryotic cell into two parts: • Nucleus • Cytoplasm
Nucleus • The nucleus is compared to the main office of the factory. • It is the control center. • The nucleus contains nearly all the cell’s DNA and with it the coded instructions for making proteins and other important molecules.
Parts of the nucleus • The nucleus is surrounded by a nuclear envelope. • The envelope contains many different pores that allow materials such as proteins, RNA, and other molecules to travel to and from the rest of the cell. • Just like the memos, instructions and blueprints move in and out of the office.
Parts of the nucleus • The nucleus contains granular material made up of DNA bound to proteins called chromatin. • During cell division, this chromatin condenses to form thread-like structures called chromosomes. • The nucleus also contains a small, dense region called the nucleolus which is responsible for the assembly of ribosomes.
Ribosomes • One of the most important products of the cell is the making of proteins. • Proteins are assembled on ribosomes. • Ribosomes are small particles of RNA and protein found in two places throughout the cell:
1. Endoplasmic Reticulum 2. Cytoplasm
• In the factory, they are the machines that produce the product.
Endoplasmic Reticulum • The endoplasmic reticulum is the site where lipid components of the cell membrane are assembled, along with proteins and other materials that are exported from the cell. • There are two types of ER’s: 1. Rough ER 2. Smooth ER
•Rough ER • Rough ER is responsible for producing proteins that are exported from the cell. • It is called rough because there are ribosomes found on the surface of the ER which gives it a bumpy surface. • The proteins made by these ribosomes enter the ER where they are modified.
• Smooth ER • Ribosomes are not found on its surface. • Contains enzymes that perform specialized tasks such as the synthesis of membrane lipids and the detoxification of drugs. • Liver cells have large amounts of smooth ER.
NOTEBOOK #4 1. What is the nucleus? 2. What is it surrounded by? 3. What is found in the nucleus? 4. What is the job of the ribosomes? 5. Where are the ribosomes found? 6. What is the job of the ER? 7. What are the two kids of ER and explain the difference.
Golgi Apparatus
• Proteins that are made in the rough ER move into the golgi apparatus. • They are a stack of apposed membranes. • The function of the golgi apparatus is to modify, sort, and package proteins and other materials from the ER for storage in the cell or secretion outside the cell. • Golgi is the customization shop where the finishing touches are put on the product.
Lysosomes • They are small organelles filled with enzymes. • They have two major jobs: 1. Digest or breakdown lipids, carbohydrates, and proteins into small molecules that can be used by the cell. 2. Ingest and destroy old and worn-out organelles. • The lysosome can be compared to the cleanup crew of the factory.
Vacuoles • Vacuoles are the storage area of the cell. They store things such as water, salts, proteins, and carbohydrates. • In plants, there is usually a large central vacuole that is filled with liquid. The pressure built up in the vacuole make it possible to support heavy structures. • In single-cell organisms, such as the paramecium, they contain a contractile vacuole that pumps out excess water to help maintain homeostasis. • Homeostasis is the maintenance of a controlled internal environment.
NOTEBOOK #5 1. What is the gologi apparatus? 2. What is the job of the golgi apparatus? 3. What are lysosomes? 4. What is the job of the lysosome? 5. What is a vacuole? 6. What is the job of the vacuole? 7. What process is maintained by the vacuole?
Mitochondria
• Mitochondria are organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell to use. • Mitochondria have two membranes - an outer membrane and an inner membrane that is folded up to create more surface area. • Mitochondria are inherited from the cytoplasm of the ovum, or egg. • Called the “Powerhouse” of the cell. • ATP is made here.
Chloroplasts • Chloroplasts
are organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis.
• They act as solar panels. The chemical that absorbs the sunlight is a green pigment called chlorophyll.
Organelle DNA • Mitochondria and Chloroplasts contain their own genetic information in the form of small DNA molecules. • They are believed to be descendants of ancient prokaryotes. • The idea suggests that the ancient prokaryotes developed a symbiotic relationship with the eukaryotes and actually took up residence within the eukaryotic cell. • This idea is called the endosymbiotic theory.
Cytoskeleton • The cytoskeleton is a network of protein filaments that helps the cell to maintain its shape. The cytoskeleton is also involved in movement. • The two main types of protein filaments • Microfilaments - thread-like structures made of actin. • Microtubules - hollow structures made of tubulins. • Play an important role in cell division. • Make up centrioles, cilia, and flagella.
NOTEBOOK #6 1. What is the job of the mitochondria? 2. What is made there? 3. How is mitochondria inherited? 4. What is the job of the choloroplast? 5. What is the chemical that absorbs the solar energy? 6. According to the endosymbiotic theory, how did mitochondira and chloroplasts end up living inside of cells? 7. What is the cytoskeleton and what is its job?
Venn Diagrams Prokaryotes
Eukaryotes
NOTEBOOK #7 Cell membrane
Animal Cells
Centrioles
Plant Cells
Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton
Cell Wall
Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton
Figure 7-5 Plant and Animal Cells Plant Cell Vacuole
Smooth endoplasmic Ribosome
Chloroplast Ribosome Cell Nuclear
Cell wall
Nucleolus Golgi apparatus Mitochondrion
Nucleus Rough endoplasmic reticulum
Figure 7-5 Plant and Animal Cells Animal Cell Ribosome Nucleolus Nucleus Nuclear Rough endoplasmic
Golgi apparatus
Ribosome Cell Mitochondrion Smooth endoplasmic
Centrioles
Figure 7-11 Cytoskeleton
Cell membrane
Endoplasmic
Microtubule
Microfilament
Ribosomes
Mitochondrion
NOTEBOOK #8
Interest Grabber
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?
Cell Boundaries • All cells are surrounded by a thin, flexible barrier known as the cell membrane. • The cell membrane regulates what enters and leaves the cell and also provides protection and support. • Nearly all cell membranes are composed of a double layered sheet called a lipid bilayer.
Cell Walls • Cell walls are present in many organisms including plants, algae, fungi, and prokaryotes. • The main function of the cell wall is to provide support and protection for the cell.
Diffusion Through Cell Boundaries • Every living cell exists in a liquid environment that it needs to survive. • One of the most important functions of the cell membrane is to regulate the movement of dissolved molecules from the liquid on one side of the membrane to the liquid on the other side.
Diffusion Through Cell Boundaries • 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 whe they are less concentrated. • Equilibrium- when the concentration of the solute is the same throughout the system
Diffusion Through Cell Boundaries • Because diffusion depends upon random particle movements, substances diffuse across membranes without requiring the cell to use energy.
Osmosis • Osmosis is the diffusion of water through a selectively permeable membrane. • Isotonic - when the concentration of two solutions is the same • Hypertonic-when comparing two solutions, the solution with the greater concentration of solutes. • Hypotonic- when comparing two solutions, the solution with the lesser concentration of solutes.
Figure 7-15 Osmosis
Facilitated Diffusion
• Movement of specific molecules across a membrane
Facilitated Glucose
High
Cell
Low
Protein
Notebook #8 • What are most cell membranes composed of? • What is the job of the cell membrane? • What types of organisms have cell walls? • What is diffusion? • What is osmosis? Define isotonic, hypertonic, and hypotonic. • What is facilitated diffusion?
Figure 7-12 The Structure of the
Outside Carbohydrate Proteins Cell
Inside of cell
Protein
Lipid bilayer
Figure 7-19 Active Transport Molecule to
Energy
Molecule
NOTEBOOK #9 1. What part of the cell membrane aids in facilitated diffusion? 2. What is the structure of the cell membrane? 3. What is osmosis? 4. What is active transport?
Interest Grabber
From Simple to More Complex
• Many multicellular organisms have structures called organs that have a specific function and work with other organs. • Working together, these organs carry out the life processes of the entire organism.
Interest Grabber continued
NOTEBOOK #10
•1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task? •2. What do you think are some characteristics of a successful team? •3. How is a multicellular organism similar to a successful team?
Levels of Organization
Muscle cell
Smooth muscle tissue
Stomach
Digestive system
Videos
• Click a hyperlink to choose a video. •
Diffusion
•
Osmosis
•
Passive Transport
•
Active Transport
•
Endocytosis and Exocytosis
Interest Grabber NOTEBOOK #11
An Important Process • While walking along a dusty path, you begin to cough. As you continue your walk, a small insect comes flying toward you. You blink and then duck so that it misses you. These actions are just a few examples of homeostasis. Homeostasis is the process by which organisms keep internal conditions relatively constant
1. List three other examples of homeostasis that occur in organisms. 2. Why is homeostasis important to an organism?
Homeostasis
The process by which organisms keep internal conditions relatively constant despite changes in external environment.
Thermoregulation
Water Regulation (Osmoregulation)
Oxygen Regulation
Video 1
Diffusion
•
Click the image to play the video segment.
Video 2
Osmosis
Click the image to play the video segment.
Video 3
Passive Transport
Click the image to play the video segment.
Video 4
Active Transport
Click the image to play the video segment.
Video 5
Endocytosis and Exocytosis
Click the image to play the video segment.
Go Online
•
The latest discoveries in cell study
•
Cell structure activity
•
Career links on histotechnologists
•
Interactive test
•
Articles on cells
•
For links on cell theory, go to www.SciLinks.org and enter the Web Code as follows: cbn-3071.
•
For links on cell membranes, go to www.SciLinks.org and enter the Web Code as follows: cbn-3073.
Interest Grabber Answers
• 1. •
What are the advantages of a one-celled organism?
A one-celled organism has simpler needs and can respond immediately to its environment because its entire cell is immersed in its environment.
• 2. What are the advantages of an organism that is made up of many cells? •
In a multicellular organism, different jobs are divided among different groups of cells that work together. Also, a multicellular organism can continue to survive even if it loses some of its cells.
Interest Grabber Answers
• 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? •
Answers may include: monitor (interfaces with the computer’s environment), software (instructions for how to carry out different jobs), CPU (directs the computer's activities), recycle bin or trash can (storage area for wastes), and so on.
• 2. How do the functions of these computer parts correspond to the functions of certain cell parts? •
Students should try to link the functions they described in question 1 to the functions of the different cell structures. The cell needs a way to interface with its environment (cell membrane), instructions for carrying out different jobs (DNA), and a CPU to direct the cell’s activities (nucleus).
Interest Grabber Answers
• •
1.
What are some things that can pass through a window screen? Answers may include air, fine dust, and rainwater.
•
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?
•
Insects, leaves, and other matter that may fall from trees. The screen keeps out annoying insects and objects that may bring dirt into the home.
•
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?
•
Materials such as oxygen and food that are needed by the cell have to be able to get inside the cell. At the same time, excess materials have to leave the cell.
Interest Grabber Answers
• 1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task? •
Answers might include building a human pyramid or constructing an arch out of blocks.
• 2. What do you think are some characteristics of a successful team? •
Divide up jobs and cooperate well with one another.
• 3.
How is a multicellular organism similar to a successful team?
•
The functions of the organism are divided up among its parts (organs and organ systems). All the parts cooperate to carry out all the functions of the whole organism.
Interest Grabber Answers
1. List three other examples of homeostasis that occur in organisms. Accept all reasonable student examples that show an understanding of homeostasis. 2. Why is homeostasis important to an organism? Homeostasis allows an organism to remain in balance with its environment. If homeostasis is not maintained, it can harm the organism
