Cell Structure and Function

Transcription

1 Name Cell Structure and Function Date How do the structures and processes of a cell enable it to survive? Before You Read Before you read the chapter, think about what you know about the topic Record your thoughts in the first column Pair with a partner, and discuss his or her thoughts Record those thoughts in the second column Then record what you would like to share with the class in the third column Think Pair Share Chapter Vocabulary Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Lesson 1 Lesson 2 Lesson 3 Lesson 4 NEW cell theory macromolecule nucleic acid protein lipid carbohydrate REVIEW theory NEW cell membrane cell wall cytoplasm cytoskeleton organelle nucleus chloroplast ACADEMIC function NEW passive transport diffusion osmosis facilitated diffusion active transport endocytosis exocytosis NEW cellular respiration glycolysis fermentation photosynthesis A Lesson Content Vocabulary page for each lesson is provided in the Chapter Resources Files Cell Structure and Function 11

2 Lesson 1 Cells and Life Skim Lesson 1 in your book Read the headings and look at the photos and illustrations Identify three things you want to learn more about as you read the lesson Write your ideas in your Science Journal Understanding Cells 43 Explain why it took so long for scientists to learn about cells Cells are too small to see without special tools No one knew that cells existed until the microscope was invented 44 Summarize discoveries made by scientists that led to the cell theory Robert Hooke built a microscope and used it to study cells for the first time; used the term cells to describe what he saw 44 Matthias Schleiden used one of the new microscopes to study plant cells and their features; noted similarities to animal cells Theodor Schwann used one of the new microscopes to study animal cells and their features; saw similarities to plant cells Rudolf Virchow proposed that all cells come from preexisting cells List the 3 main principles of the cell theory 1 All living things are made of one or more cells 2 The cell is the smallest unit of life 3 All new cells come from preexisting cells Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 12 Cell Structure and Function

3 Lesson 1 Cells and Life (continued) Basic Cell Substances 45 Organize information about macromolecules Macromolecules have important roles in how a cell functions cannot function without water form by joining many smaller molecules together 45 Complete the statement about basic cell substances The main material inside cells is water, which makes up more than 75 percent of the cell s volume Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 45 Draw a water molecule in the space below Color the oxygen red and the hydrogen blue, and label the positive and negative ends In the space below your drawing, describe the structure of the water molecule, and explain: 1 how that structure helps dissolve materials; 2 why water s ability to dissolve materials is important to the function of a cell Drawings should show a large central red oxygen atom with two smaller blue hydrogen atoms attached to it Students should indicate that the oxygen end is negative (-) and the hydrogen end is positive (+) The water molecule has a positive end and a negative end This structure makes substances dissolve easily because the positive ends of the water molecules can attract the negative parts of other substances and the positive ends can attract negative parts Materials can only enter into and exit from cells when dissolved in water Cell Structure and Function 13

4 Lesson 1 Cells and Life (continued) 46 Identify the types of macromolecules inside cells Types of Macromolecules in Cells nucleic acids lipids proteins carbohydrates 46 Distinguish 2 types of nucleic acids and indicate what cells make with each type 1 DNA is used to make RNA 2 RNA is used to make proteins Identify 4 functions of proteins 1 communication 3 chemical breakdown of substances 2 transport 4 structural support Explain why lipids are able to function as protective barriers in cells They do not dissolve in water Summarize information about carbohydrates 1 2 that provide energy sugars starches Carbohydrates 1 that provide support cellulose Describe how the development of cell theory shows that scientific ideas can change over time Use specific examples Sample answer: When Robert Hooke first saw cells, he did not know what they were and called them little rooms As scientists used better equipment, they began to see Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc cells in greater detail and to realize that cells contained other things They also learned that all living things are made of cells and that all cells come from other cells 14 Cell Structure and Function

5 Lesson 2 The Cell Scan Lesson 2 in your book Think of three questions you have about cells Write those questions in your Science Journal Then try to answer your questions as you read Cell Shape and Movement Compare cell parts by completing the chart Put a check mark in the Plant or Animal column to indicate which types of cells contain the cell part listed You might need to reference the cell diagrams to decide Cell Part Plant Animal Description: a flexible covering around the cell 52 Cell membrane Purpose: protects the inside of a cell from the environment outside a cell Description: a stiff structure outside the cell membrane Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Cell wall Cytoplasm Cytoskeleton Purpose: maintains cell s shape; protects cell from harmful organisms Description: fluid inside a cell that contains salts and molecules Purpose: provides water environment in which cell processes take place Description: threadlike proteins joined together Purpose: gives a cell shape and helps it move Cell Structure and Function 15

6 Lesson 2 The Cell (continued) 53 Identify and describe 2 examples of cell appendages 1 Example: Description: cilia short, hairlike structures Purpose: can move a cell or move molecules away from a cell 2 Example: flagella Description: whiplike structures Purpose: movement Cell Types 54 Classify cells as prokaryotic or eukaryotic by writing E or P in the right-hand column Characteristic Cell s genetic material is surrounded by a membrane Cell is usually a unicellular organism It is usually the smaller of the two types of cell Cell contains organelles Cell Type E P P E Cell Organelles Identify four facts about organelles Sample answers shown surrounded by a membrane have a specialized function inside eukaryotic cells enable a cell to carry out many functions at once Describe some functions of organelles process energy and get rid of waste What Organelles Do for Cells store genetic information make macromolecules Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 16 Cell Structure and Function

7 Lesson 2 The Cell (continued) Classify information about organelles In the right-hand column, indicate whether the organelle is in a plant cell, an animal cell, or Organelle Function Sample answers are shown Plant, Animal, or Both? 55 Nucleus directs all cell activity and stores genetic information 55 Nucleolus makes ribosomes 55 Ribosome makes proteins Rough endoplasmic reticulum Smooth endoplasmic reticulum provides a site for making proteins makes lipids and helps remove harmful substances from cell 56 Mitochondria releases energy from ATP molecules Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Chloroplast Golgi apparatus Vesicle Central vacuole Lysosome uses energy from sunlight and makes glucose prepares proteins for their specific jobs and packages them into vesicles transports substances to different areas within the cell stores food, water, and waste material helps break down and recycle cellular components plant plant animal Some cells contain chloroplasts that use light energy and produce food Do cells without chloroplasts also depend on sunlight for their food? Explain Sample answer: Yes; cells without chloroplasts also depend on sunlight for their food They use the sugars made by cells with chloroplasts for energy Cell Structure and Function 17

8 Lesson 3 Moving Cellular Material Predict three things that will be discussed in Lesson 3 Read the headings, and look at the photos and illustrations Write your predictions in your Science Journal Passive Transport List 2 functions of membranes 1 boundaries between cells and between organelles 2 control movement of substances into and out of cells Organize information about passive transport Passive Transport Diffusion 62 Definition: Depends on: Example: amount of substance on each side of the membrane the movement of substances through a cell membrane without using the cell s energy Assess information about diffusion Read the statements below If the statement is true, write true on the line I f it is false, rewrite the underlined portion of the statement so that it is true Diffusion is the movement of substances from an area of lower concentration to an area of higher concentration False; higher concentration, lower concentration Oxygen molecules move across a cell membrane until the amount of oxygen is equal on sides of the membrane Diffusion continues until the concentration of a substance is higher inside a cell than outside a cell False; the same on sides of a cell s membrane Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 18 Cell Structure and Function

9 Lesson 3 Moving Cellular Material (continued) Osmosis The Diffusion of Water Complete the sentence about osmosis Osmosis is a type of passive transport that involves movement of water molecules only through the cell membrane Explain the process of facilitated diffusion Facilitated Diffusion A molecule is too large to pass through a cell membrane Cell uses two types of transport proteins carrier proteins channel proteins Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Active Transport 64 pass large molecules through membrane by carrying them through Organize information about active transport Definition: the movement of substances through a cell membrane only by using the cell s energy Active Transport can move substances from areas of lower concentration to higher concentration pass large molecules through membrane by forming a pore through the membrane through which the molecule can pass used to bring in nutrients and take waste out Cell Structure and Function 19

10 Lesson 3 Moving Cellular Material (continued) 64 Compare and contrast facilitated diffusion and active transport by writing or no in each empty box of the chart Description Uses carrier proteins Transports materials across cell membrane Requires cellular energy Able to move materials from an area with lower concentration to an area with higher concentration Facilitated Diffusion no no Active Transport 64 Identify each process as either endocytosis or exocytosis Process endocytosis Description Materials entering cell exocytosis Materials being expelled from cell Cell Size and T ransport 65 Explain how cell size and transport are related Underline the term that correctly completes each sentence As a cell grows, its volume and surface area (increase/ decrease) Volume increases (faster/slower) than surface area Eventually, the cell s membrane would be (too large/too small) to move enough materials into and out of the cell Cells are very small Yet, as living things, they have the ability to grow What keeps cells from growing to much larger sizes than they do? Accept all reasonable responses Sample answer: For transport of materials, a cell s surface area must be much larger than its volume As a cell grows, its volume increases more quickly than its surface area If a cell were to keep growing, its membrane would not be able to transport enough materials for the cell to survive Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 20 Cell Structure and Function

11 Lesson 4 Cells and Energy Scan Lesson 4 in your book Think of three questions you have about cells and energy Write those questions in your Science Journal Then try to answer your questions as you read Cellular Respiration 69 Organize information about cellular respiration What it is: a series of chemical reactions Cellular Respiration What it does: converts the energy in food into ATP W here it occurs: 1 cytoplasm 2 mitochondria Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc 69 Cell membrane Glucose (sugar) ATP Chemical reactions Smaller molecules Cytoplasm ATP Summarize the first step in the process of cellular respiration Then label the steps in the diagram on the left breaks glucose smaller molecules First Step of Cellular Respiration occurs in is called glycolysis, a process that into cytoplasm produces some molecules ATP Cell Structure and Function 21

12 Lesson 4 Cells and Energy (continued) 70 Describe the second step of cellular respiration food energy Mitochondria oxygen Waste products: 1 water 2 carbon dioxide Fermentation I f ound this on page Define fermentation by completing the sentences When cells do not have enough oxygen to make ATP through cellular respiration, they use a process called fermentation Because no oxygen is used, less ATP is produced cellular respiration than in Compare fermentation to cellular respiration What gets broken down? Where does the breakdown occur? Is energy released? Fermentation glucose cytoplasm only Sequence the 2 types of fermentation Cellular Respiration glucose cytoplasm and mitochondria muscle cells use glucose to produce ATP + Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc lactic acid ATP yeast cells use + CO 2 + glucose alcohol to produce 22 Cell Structure and Function

13 Lesson 4 Cells and Energy (continued) Photosynthesis 72 Diagram the reactions that occur in chloroplasts during photosynthesis in the space below Show what goes into and comes out of this process Use these terms: sugar oxygen light energy water carbon dioxide Accept any diagram that shows this relationship: light energy + water + carbon dioxide sugar + oxygen 72 C r e a t e a cycle diagram that shows the relationship between photosynthesis and cellular respiration Use the terms chloroplast, glucose, oxygen, water, carbon dioxide, light energy, and mitochondrion in your model Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Diagram should show sunlight energy entering the cycle before the chloroplast, chloroplast producing glucose and oxygen, those products going to a mitochondrion, which releases energy and produces carbon dioxide and water, which enters the chloroplast once again through sunlight energy to start the process over Why is photosynthesis important to living things other than plants? Sample answer: Students should conclude that without photosynthesis, plants and some other organisms cannot make food If these organisms cannot make food, they cannot survive and act as food for other living things that cannot make their own food Cell Structure and Function 23

14 Review Chapter Wrap-Up Cell Structure and Function Now that you have read the chapter, think about what you have learned Use this checklist to help you study Complete your Foldables Chapter Project Study your Science Notebook on this chapter Study the definitions of vocabulary words Reread the chapter, and review the charts, graphs, and illustrations Review the Understanding Key Concepts at the end of each lesson Look over the Chapter Review at the end of the chapter Reread the chapter Big Idea and the lesson Key Concepts When scientists first began to study cells, they found that plant and animal cells were similar to each other and yet different from each other What are the similarities that you have noticed? What are the differences? Accept all reasonable responses Students should explain that types of cells have the same kinds of organelles, except that plant cells have chloroplasts, central vacuoles, and cell walls They should also explain that the processes inside the cells are similar, except that plant cells can photosynthesize their food Copyright Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc Challenge Compare the cell to a factory For example, a factory has a manager, and a cell has a nucleus Use similar analogies to describe the functions of different parts of the cell 24 Cell Structure and Function