7. A selectively permeable membrane only allows certain molecules to pass through.
|
|
- Lesley Harmon
- 5 years ago
- Views:
Transcription
1 CHAPTER 2 GETTING IN & OUT OF CELLS PASSIVE TRANSPORT Cell membranes help organisms maintain homeostasis by controlling what substances may enter or leave cells. Some substances can cross the cell membrane without any input of energy by the cell. The movement of such substances across the membrane is known as passive transport. ions cannot. 6. The cell membrane is thus said to be partially permeable. 1. The activities of a cell depend on the materials that enter and leave the cell. 2. To stay alive, a cell must exchange materials such as food, oxygen and waste with its surroundings. 3. These materials must cross the cell membrane. 4. Small molecules like water, oxygen and carbon dioxide can move in and out freely, since they can squeeze between the molecules of the membrane. 5. Large or charged molecules like proteins, sugars and 7. A selectively permeable membrane only allows certain molecules to pass through. SIMPLE DIFFUSION 1. The simplest type of passive transport, diffusion does not require the cell to use energy. Only small molecules can cross the cell membrane by simple diffusion. 2. Diffusion is the movement of molecules from an area of high concentration to one of low concentration. 3. This difference in the concentration of molecules across a space is called the concentration gradient. 4. Diffusion is driven by the kinetic energy of the molecules. Because of their KE, molecules are in constant motion. Diffusion occurs when molecules move randomly away from each other in a liquid or gas. 5. The rate of diffusion depends on the temperature, size and the type of molecules that are diffusing. 6. Molecules diffuse faster at higher temperatures than at lower temperatures, and smaller molecules diffuse faster than large molecules. 7. Most transport of materials into and out of cells occurs by diffusion. 8. The concentration gradient is the difference between the concentration of a solute in one place and its concentration in an adjacent area. 9. Remember: Fick s Law, i.e. Diffusion α surface area x concentration difference distance
2 10. Diffusion always occurs down a concentration gradient, i.e. from the area of higher concentration to the area of lower concentration. 11. When molecules are dispersed evenly, there is no longer any diffusion because there is no longer a concentration gradient. 12. Diffusion will eventually cause the concentration of molecules to be the same throughout the space the molecules occupy, when they will be in equilibrium. OSMOSIS Osmosis is The process by which water molecules diffuse across a partially permeable membrane from a region of higher water potential to a region of lower water potential. The symbol for water potential is the Greek letter Ψ (psi) or Ψ w. Water moves by diffusion, like any other molecule, from a region of high concentration to one of low concentration, i.e. down its concentration gradient. Confusion occurs because concentration normally refers to the solute concentration, whereas, in this case, we are referring to the solvent concentration. For this reason, the use of the term water potential is essential; water then simply moves down the water potential gradient easy! The water potential of pure water is zero (0), so, since a solution must always be less than 100% pure water, all solutions (and cells) have a negative (-) water potential. The strength of a solution is given by its solute potential (Ψ s ). The stronger the solution, the more negative this value will be. One large and one small molecule will both have the same osmotic effect (i.e. lower Ψ s by the same amount). So, a single molecule of protein will have about 100 times less effect than the individual amino-acid molecules that make it up. Insoluble molecules do not affect the solute potential (obviously), so have no osmotic effect. Such molecules are used for storage starch, lipids, and very large proteins (albumin). Water potential is actually a pressure, and is measured in Pascals (Pa), but since these are so small the normal unit is the kilo Pascal (kpa). Typical plant values are -200 to -2000kPa. Plants have a cell wall which normally presses on the cell membrane, giving us the pressure potential (Ψ p ). Since this opposes the tendency of the cell to expand due to osmosis, it therefore follows that the pressure potential (Ψ p ) is always positive.
3 Since animals have no cell wall, and so no pressure potential, the solute potential and the water potential must be the same: (Ψ w ) = (Ψ p ) Similar logic shows that the water potential of every cell in an animals body must be the same, since they are all in contact with blood, and thus in equilibrium ( two values that are equal to a third value, must be equal to each other ) When a plant cell is turgid (its normal state), the net movement of water into and out of the cell is zero. Thus: (Ψ w ) = (Ψ s ) + (Ψ p ) Note that calculations on this will not be set in the exam. The net direction of osmosis depends on the relative concentration of solutes on the two sides of the cell membrane. In a hypertonic solution, the concentration of solutes in the solution is higher and so it has a lower (i.e. more negative) water potential (Ψ w ). Therefore, when placed in a hypertonic solution, water leaves the cell by osmosis, until equilibrium is established. If the cell loses too much water, the cell will shrivel and shrink. Eventually they die, as their metabolism is disrupted i.e. badly wilted plants never recover fully Conversely, cells in a hypotonic (or weaker) solution will absorb water by osmosis until equilibrium is reached, since the cell has the lower water potential, and water flows downhill. This flow of water into a cell causes it to swell: a. Animal cells placed in a hypotonic solution will swell and often burst because of osmosis. N.B. The bursting of cells is called cytolysis. b. Plant, fungal and bacterial cells do not burst because of their cell wall. The pressure that the cell exerts against the cell wall is its pressure potential Ψ p. These cells are normally in this state, i.e. turgid. In an isotonic solution, the concentration of solutes on both sides of the membrane is the same and so the net movement of water is zero. This is the normal position inside an animal s body.
4 HOW CELLS DEAL WITH OSMOSIS 1. Cells that are exposed to an isotonic environment have no difficulty keeping the movement of water across the cell membrane in balance. This includes all land and most marine animals. 2. However, cells functioning in a hypotonic environment, such as Protoctista living in fresh water have a problem, as water will constantly enter them, down the water potential gradient, from their surroundings. 3. Since they cannot lower their water potential to near-zero, such organisms must rid themselves of the excess water. 4. Some (e.g. Paramecium see left) have contractile vacuoles, which actively pump water out of the cell. 5. This pumping action requires energy so is a form of active transport. Up to 30% of the cell s energy may be used in this way. 6. Plant root cells also live in hypotonic environment, so water (only!) normally moves by osmosis into the root hair cells, until they are turgid. Water then moves from these cells into the xylem down the water potential gradient (see Module 5 notes!) 7. In a hypertonic environment, water leaves the cells by osmosis, the cell membrane shrinks away from the cell wall, and turgor is lost. This condition is called plasmolysis, and is the reason plants wilt. The effect of osmosis in: a) hypertonic solution b) isotonic solution c) hypotonic solution.
5 FACILITATED DIFFUSION 1. Passive transport across a membrane requires no energy input from the cell and always goes down the concentration gradient. Simple diffusion and osmosis are examples of passive transport. 2. However, most molecules cannot cross the membrane by simple diffusion; to do so, the molecule must either be very small (H 2 O, CO 2 ) or be soluble in both water and lipid (ethanol). 3. Some molecules are carried across the membrane by carrier proteins which are embedded in the cell membrane. 4. Carrier proteins often change shape when molecules attach to them, and this change in shape enables the molecule to cross the membrane. 5. Because the carrier protein has to fit around the molecule, it is specific to one molecule, or related class of molecules. 6. This use of carrier proteins to cross the membrane is known as facilitated diffusion, and can be used by those molecules to cross the membrane in either direction into or out of the cell. 7. Like simple diffusion, facilitated diffusion always goes down the concentration gradient, and therefore continues until equilibrium is reached, for that molecule (see below) 8. A good example of facilitated diffusion is the transport of glucose into the cell. Once inside the cell, the glucose is immediately turned into glucose phosphate, for which no carrier protein exists. Glucose will thus continue to enter the cell, since equilibrium can never be reached! 9. Facilitated diffusion is therefore another form of passive transport, since it requires no energy input from the cell. 10. Some molecules, mainly ions (e.g. Na +, K + ) cross the membrane through tunnels made of protein called ion channels. 11. Some ion channels are always open, but others (e.g. in neurones) have gates that open to allow ions to pass or close to stop their passage. 12. Gates open and close in response to conditions in the external environment, or in the cell. It is the opening and closing of the sodium and potassium gates that allows a nerve impulse to be formed and passed along a neurone.
6 CELL MEMBRANE PUMPS ACTIVE TRANSPORT (using ATP energy) 1. Cells often move molecules across the membrane against the concentration gradient, i.e. from an area of low concentration to an area of high concentration. 2. This requires energy (uses ATP), and is known as active transport. 3. Active transport involves the use of carrier proteins, similar to those of facilitated diffusion, but these carrier proteins act as pumps, using the energy from splitting ATP to pump specific molecules against the concentration gradient. 4. These carrier proteins are known as membrane pumps, and are particularly important in maintaining the Na + /K + ion balance between Eukaryotic cells and their external environment. 5. The sodium/potassium (Na + /K + ) pump maintains a high concentration of Na + ions outside the cell, and a high concentration of K + ions inside the cell. This is particularly important in muscle contractions, nerve impulses and the absorption of nutrients from the gut. 6. The Na + /K + ion pump moves Na + ions out of the cell, and K + ions into the cell, against their concentration gradient, using ATP to supply the energy needed. 7. In plants, active transport enables roots to absorb mineral ions from the soil, which are therefore more concentrated inside plant cells than in the soil. 8. This requires ATP energy from aerobic respiration, and therefore roots need oxygen to allow mineral uptake and a waterlogged (thus anaerobic) soil will kill most roots. Summary of the different methods by which molecules can enter cells.
7 BULK TRANSPORT (endocytosis and exocytosis) 1. Some molecules, such as large proteins, are too large to cross the cell membrane, and enter by bulk transport. Other examples include food particles and bacteria (phagocytes). 2. These are all packaged in membrane-bound sacs called b and moved across the membrane in this way. 3. Endocytosis means substances entering the cell; exocytosis means substances leaving the cell. 4. During endocytosis the cell membrane folds into a pouch that encloses the particles, before pinching itself off to form the vesicle. 5. The vesicle often then fuses with a lysosome, which releases its contents to digest the contents of the vesicle. 6. This is thus a form of cell feeding called phagocytosis. When the particles absorbed are very small (e.g. proteins), it is referred to as pinocytosis, (or cell drinking ). 8. White blood cells (WBC s) known as phagocytes, destroy bacteria and other unwanted body cells by phagocytosis, including many millions of old RBC s broken down in the liver. 9. Exocytosis is the opposite of endocytosis and can be used for secretion (e.g. hormones, and enzymes, packaged in the Golgi apparatus) or for excretion of waste products (indigestible parts of food from Amoeba) IHW September 2005
Osmosis, Diffusion and Cell Transport
Osmosis, Diffusion and Cell Transport Types of Transport There are 3 types of transport in cells: 1. Passive Transport: does not use the cell s energy in bringing materials in & out of the cell 2. Active
1.1.2. thebiotutor. AS Biology OCR. Unit F211: Cells, Exchange & Transport. Module 1.2 Cell Membranes. Notes & Questions.
thebiotutor AS Biology OCR Unit F211: Cells, Exchange & Transport Module 1.2 Cell Membranes Notes & Questions Andy Todd 1 Outline the roles of membranes within cells and at the surface of cells. The main
Membrane Structure and Function
Membrane Structure and Function Part A Multiple Choice 1. The fluid mosaic model describes membranes as having A. a set of protein channels separated by phospholipids. B. a bilayer of phospholipids in
Six major functions of membrane proteins: Transport Enzymatic activity
CH 7 Membranes Cellular Membranes Phospholipids are the most abundant lipid in the plasma membrane. Phospholipids are amphipathic molecules, containing hydrophobic and hydrophilic regions. The fluid mosaic
FIGURE 2.18. A. The phosphate end of the molecule is polar (charged) and hydrophilic (attracted to water).
PLASMA MEMBRANE 1. The plasma membrane is the outermost part of a cell. 2. The main component of the plasma membrane is phospholipids. FIGURE 2.18 A. The phosphate end of the molecule is polar (charged)
Date: Student Name: Teacher Name: Jared George. Score: 1) A cell with 1% solute concentration is placed in a beaker with a 5% solute concentration.
Biology Keystone (PA Core) Quiz Homeostasis and Transport - (BIO.A.4.1.1 ) Plasma Membrane, (BIO.A.4.1.2 ) Transport Mechanisms, (BIO.A.4.1.3 ) Transport Facilitation Student Name: Teacher Name: Jared
Chapter 8. Movement across the Cell Membrane. AP Biology
Chapter 8. Movement across the Cell Membrane More than just a barrier Expanding our view of cell membrane beyond just a phospholipid bilayer barrier phospholipids plus Fluid Mosaic Model In 1972, S.J.
4. Biology of the Cell
4. Biology of the Cell Our primary focus in this chapter will be the plasma membrane and movement of materials across the plasma membrane. You should already be familiar with the basic structures and roles
CHAPTER 5.1 5.2: Plasma Membrane Structure
CHAPTER 5.1 5.2: Plasma Membrane Structure 1. Describe the structure of a phospholipid molecule. Be sure to describe their behavior in relationship to water. 2. What happens when a collection of phospholipids
Homeostasis and Transport Module A Anchor 4
Homeostasis and Transport Module A Anchor 4 Key Concepts: - Buffers play an important role in maintaining homeostasis in organisms. - To maintain homeostasis, unicellular organisms grow, respond to the
Cell Membrane & Tonicity Worksheet
NAME ANSWER KEY DATE PERIOD Cell Membrane & Tonicity Worksheet Composition of the Cell Membrane & Functions The cell membrane is also called the PLASMA membrane and is made of a phospholipid BI-LAYER.
Section 7-3 Cell Boundaries
Note: For the past several years, I ve been puzzling how to integrate new discoveries on the nature of water movement through cell membranes into Chapter 7. The Section below is a draft of my first efforts
Biological cell membranes
Unit 14: Cell biology. 14 2 Biological cell membranes The cell surface membrane surrounds the cell and acts as a barrier between the cell s contents and the environment. The cell membrane has multiple
BIOL 305L Laboratory Two
Please print Full name clearly: Introduction BIOL 305L Laboratory Two Osmosis, because it is different in plants! Osmosis is the movement of solvent molecules through a selectively permeable membrane into
Modes of Membrane Transport
Modes of Membrane Transport Transmembrane Transport movement of small substances through a cellular membrane (plasma, ER, mitochondrial..) ions, fatty acids, H 2 O, monosaccharides, steroids, amino acids
Lab 4: Osmosis and Diffusion
Lab 4: Osmosis and Diffusion The plasma membrane enclosing every cell is the boundary that separates the cell from its external environment. It is not an impermeable barrier, but like all biological membranes,
Anatomy and Physiology Placement Exam 2 Practice with Answers at End!
Anatomy and Physiology Placement Exam 2 Practice with Answers at End! General Chemical Principles 1. bonds are characterized by the sharing of electrons between the participating atoms. a. hydrogen b.
Ch. 8 - The Cell Membrane
Ch. 8 - The Cell Membrane 2007-2008 Phospholipids Phosphate head hydrophilic Fatty acid tails hydrophobic Arranged as a bilayer Phosphate attracted to water Fatty acid repelled by water Aaaah, one of those
Membrane Transport. Extracellular Concentration of X
Use the following graph to answer questions 1 and 2. Rate of diffusion of X into the cell 1. Which of the following processes is represented by the above graph? c. Active transport 2. Molecule X is most
Cell Transport and Plasma Membrane Structure
Cell Transport and Plasma Membrane Structure POGIL Guided Inquiry Learning Targets Explain the importance of the plasma membrane. Compare and contrast different types of passive transport. Explain how
Multiple Choice Questions
Chapter 5 THE FUNDAMENTAL UNIT OF LIFE Multiple Choice Questions 1. Which of the following can be made into crystal? (a) A Bacterium (b) An Amoeba (c) A Virus (d) A Sperm 2. A cell will swell up if (a)
Cell Membrane Coloring Worksheet
Cell Membrane Coloring Worksheet Composition of the Cell Membrane & Functions The cell membrane is also called the plasma membrane and is made of a phospholipid bilayer. The phospholipids have a hydrophilic
Keystone Review Practice Test Module A Cells and Cell Processes. 1. Which characteristic is shared by all prokaryotes and eukaryotes?
Keystone Review Practice Test Module A Cells and Cell Processes 1. Which characteristic is shared by all prokaryotes and eukaryotes? a. Ability to store hereditary information b. Use of organelles to control
CELL MEMBRANE & CELL TRANSPORT (PASSIVE and ACTIVE) Webquest
Name: Period: CELL MEMBRANE & CELL TRANSPORT (PASSIVE and ACTIVE) Webquest PART I: CELL MEMBRANES WEBSITE #1: http://www.wisc-online.com/objects/index_tj.asp?objid=ap1101 1. What is the BASIC UNIT of LIFE?
Diffusion, Osmosis, and Membrane Transport
Diffusion, Osmosis, and Membrane Transport Introduction... 2 Diffusion and osmosis as related to cellular processes... 2 The hotter the medium, the faster the molecules diffuse... 2 TASK 1: TEMPERATURE
Cell Biology - Part 2 Membranes
Cell Biology - Part 2 Membranes The organization of cells is made possible by membranes. Membranes isolate, partition, and compartmentalize cells. 1 Membranes isolate the inside of the cell from the outside
Membrane Structure and Function
Membrane Structure and Function -plasma membrane acts as a barrier between cells and the surrounding. -plasma membrane is selective permeable -consist of lipids, proteins and carbohydrates -major lipids
Lesson Aim To explain the human body at a microscopic level, including the structure and function of cells, tissues and membranes.
LESSON 1. CELLS & TISSUES Lesson Aim To explain the human body at a microscopic level, including the structure and function of cells, tissues and membranes. THE CELL All living matter is composed of functional
Cell Membrane Structure (and How to Get Through One)
Cell Membrane Structure (and How to Get Through One) A cell s membrane is a wall of sorts that defines the boundaries of a cell. The membrane provides protection and structure for the cell and acts as
Cells & Cell Organelles
Cells & Cell Organelles The Building Blocks of Life H Biology Types of cells bacteria cells Prokaryote - no organelles Eukaryotes - organelles animal cells plant cells Cell size comparison Animal cell
CELL MEMBRANES, TRANSPORT, and COMMUNICATION. Teacher Packet
AP * BIOLOGY CELL MEMBRANES, TRANSPORT, and COMMUNICATION Teacher Packet AP* is a trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production
Cell and Membrane Practice. A. chromosome B. gene C. mitochondrion D. vacuole
Name: ate: 1. Which structure is outside the nucleus of a cell and contains N?. chromosome. gene. mitochondrion. vacuole 2. potato core was placed in a beaker of water as shown in the figure below. Which
Chapter 7: Membrane Structure and Function
Name Period Concept 7.1 Cellular membranes are fluid mosaics of lipids and proteins 1. The large molecules of all living things fall into just four main classes. Name them. 2. Explain what is meant when
PRESTWICK ACADEMY NATIONAL 5 BIOLOGY CELL BIOLOGY SUMMARY
Name PRESTWICK ACADEMY NATIONAL 5 BIOLOGY CELL BIOLOGY SUMMARY Cell Structure Identify animal, plant, fungal and bacterial cell ultrastructure and know the structures functions. Plant cell Animal cell
Chapter 3. Cellular Structure and Function Worksheets. 39 www.ck12.org
Chapter 3 Cellular Structure and Function Worksheets (Opening image copyright by Sebastian Kaulitzki, 2010. Used under license from Shutterstock.com.) Lesson 3.1: Introduction to Cells Lesson 3.2: Cell
Chapter 36: Resource Acquisition & Transport in Vascular Plants
Chapter 36: Resource Acquisition & Transport in Vascular Plants 1. Overview of Transport in Plants 2. Transport of Water & Minerals 3. Transport of Sugars 1. Overview of Transport in Plants H 2 O CO 2
Get It Right. Answers. Chapter 1: The Science of Life. A biologist studies all living things.
Discover Biology 'N' Level Science Chapter 1 Chapter 1: The Science of Life A biologist studies all living things. In order to carry out the scientific method, we need to ask questions. Discover Biology
Investigating cells. Cells are the basic units of living things (this means that all living things are made up of one or more cells).
SG Biology Summary notes Investigating cells Sub-topic a: Investigating living cells Cells are the basic units of living things (this means that all living things are made up of one or more cells). Cells
Todays Outline. Metabolism. Why do cells need energy? How do cells acquire energy? Metabolism. Concepts & Processes. The cells capacity to:
and Work Metabolic Pathways Enzymes Features Factors Affecting Enzyme Activity Membrane Transport Diffusion Osmosis Passive Transport Active Transport Bulk Transport Todays Outline -Releasing Pathways
tissues are made of cells that work together, organs are )
Study Guide Cells Unit Test Matching. Write the letter of the correct response on the line. You may use the responses more than once. A. proteins B. simple carbohydrates C. complex carbohydrates D. lipids
IB104 - Lecture 9 - Membranes
There have been many magnificent boats built to try to reach 50 knots. This was the creation of an Australian team that held the record for more than a decade, from 1993 till 2005, at 46.5 knots with their
Cell Unit Practice Test #1
ell Unit Practice Test #1 Name: ate: 1. Which organelle is primarily concerned with the conversion of potential energy of organic compounds into suitable form for immediate use by the cell?. mitochondria.
Ions cannot cross membranes. Ions move through pores
Ions cannot cross membranes Membranes are lipid bilayers Nonpolar tails Polar head Fig 3-1 Because of the charged nature of ions, they cannot cross a lipid bilayer. The ion and its cloud of polarized water
PART I: Neurons and the Nerve Impulse
PART I: Neurons and the Nerve Impulse Identify each of the labeled structures of the neuron below. A. B. C. D. E. F. G. Identify each of the labeled structures of the neuron below. A. dendrites B. nucleus
Cell Structure and Function
Bio 100 - Cells 1 Cell Structure and Function Tenets of Cell Theory 1. All living things are made up of one or more cells 2. Cells are the basic living units within organisms, and the chemical reactions
Cellular Structure and Function
Chapter Test A CHAPTER 7 Cellular Structure and Function Part A: Multiple Choice In the space at the left, write the letter of the term or phrase that best answers each question. 1. Which defines a cell?
Introduction to the Cell: Plant and Animal Cells
Introduction to the Cell: Plant and Animal Cells Tissues, Organs, and Systems of Living Things Cells, Cell Division, and Animal Systems and Plant Systems Cell Specialization Human Systems All organisms
Cell membranes and transport. Learning Objective:
Cell membranes and transport Content Fluid mosaic model of membrane structure Movement of substances into and out of cells Learning Objective: a. Describe and explain the fluid mosaic model of membrane
AP Biology-Chapter #6 & 7 Review
DO NOT WRITE ON THIS TEST- USE ANSWER DOCUMENT AP Biology-Chapter #6 & 7 Review Multiple Choice Identify the choice that best completes the statement or answers the question. 1. All of the following are
3) Transpiration creates a force that pulls water upward in. xylem. 2) Water and minerals transported upward form roots to shoots in.
3) Transpiration creates a force that pulls water upward in xylem Figure 36.1 An overview of transport in whole plants (Layer 1) Transport in plants 2) Water and minerals transported upward form roots
Biology Chapter 7 Practice Test
Biology Chapter 7 Practice Test Multiple Choice Write the letter that best answers the question or completes the statement on the line provided. 1. The work of Schleiden and Schwann can be summarized by
Cells and Their Housekeeping Functions Cell Membrane & Membrane Potential
Cells and Their Housekeeping Functions Cell Membrane & Membrane Potential Shu-Ping Lin, Ph.D. Institute of Biomedical Engineering E-mail: splin@dragon.nchu.edu.tw Website: http://web.nchu.edu.tw/pweb/users/splin/
BSC 2010 - Exam I Lectures and Text Pages. The Plasma Membrane Structure and Function. Phospholipids. I. Intro to Biology (2-29) II.
BSC 2010 - Exam I Lectures and Text Pages I. Intro to Biology (2-29) II. Chemistry of Life Chemistry review (30-46) Water (47-57) Carbon (58-67) Macromolecules (68-91) III. Cells and Membranes Cell structure
Transport in Plants Notes AP Biology Mrs. Laux 3 levels of transport occur in plants: 1. Uptake of water and solutes by individual cells
3 levels of transport occur in plants: 1. Uptake of water and solutes by individual cells -for photosynthesis and respiration -ex: absorption of H 2 O /minerals by root hairs 2. Short distance cell-to-cell
Questions on The Nervous System and Gas Exchange
Name: Questions on The Nervous System and Gas Exchange Directions: The following questions are taken from previous IB Final Papers on Topics 6.4 (Gas Exchange) and 6.5 (Nerves, hormones and homeostasis).
PHOTOSYNTHESIS AND CELLULAR RESPIRATION
reflect Wind turbines shown in the photo on the right are large structures with blades that move in response to air movement. When the wind blows, the blades rotate. This motion generates energy that is
Absorption of Drugs. Transport of a drug from the GI tract
Absorption of Drugs Absorption is the transfer of a drug from its site of administration to the bloodstream. The rate and efficiency of absorption depend on the route of administration. For IV delivery,
Cells, tissues and organs
Chapter 8: Cells, tissues and organs Cells: building blocks of life Living things are made of cells. Many of the chemical reactions that keep organisms alive (metabolic functions) take place in cells.
7 Answers to end-of-chapter questions
7 Answers to end-of-chapter questions Multiple choice questions 1 B 2 B 3 A 4 B 5 A 6 D 7 C 8 C 9 B 10 B Structured questions 11 a i Maintenance of a constant internal environment within set limits i Concentration
CELL/ PHOTOSYNTHESIS/ CELLULAR RESPIRATION Test 2011 ANSWER 250 POINTS ANY WAY IN WHICH YOU WANT
CELL/ PHOTOSYNTHESIS/ CELLULAR RESPIRATION Test 2011 ANSWER 250 POINTS ANY WAY IN WHICH YOU WANT Completion: complete each statement. (1 point each) 1. All cells arise from. 2. The basic unit of structure
The chemical reactions inside cells are controlled by enzymes. Cells may be specialised to carry out a particular function.
12.1 What are animals and plants built from? All living things are made up of cells. The structures of different types of cells are related to their functions. to relate the structure of different types
Human Anatomy & Physiology I with Dr. Hubley. Practice Exam 1
Human Anatomy & Physiology I with Dr. Hubley Practice Exam 1 1. Which definition is the best definition of the term gross anatomy? a. The study of cells. b. The study of tissues. c. The study of structures
Chapter 4: A Tour of the Cell. 1. Cell Basics. Limits to Cell Size. 1. Cell Basics. 2. Prokaryotic Cells. 3. Eukaryotic Cells
Chapter 4: A Tour of the Cell 1. Cell Basics 2. Prokaryotic Cells 3. Eukaryotic Cells 1. Cell Basics Limits to Cell Size There are 2 main reasons why cells are so small: If cells get too large: 1) there
Biology I. Chapter 7
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.
1. The leaf is the main photosynthetic factory (Fig. 36.1, p. 702)
TRANSPORT IN PLANTS A. Introduction 1. The leaf is the main photosynthetic factory (Fig. 36.1, p. 702) a. This requires a transport system to move water and minerals from the roots to the leaf. This is
Cellular Energy. 1. Photosynthesis is carried out by which of the following?
Cellular Energy 1. Photosynthesis is carried out by which of the following? A. plants, but not animals B. animals, but not plants C. bacteria, but neither animals nor plants D. all living organisms 2.
COMPARISON OF PLANT AND ANIMAL CELLS SIMILARITIES IN PLANT & ANIMAL CELLS
COMPARISON OF PLANT AND ANIMAL CELLS Cells vary widely in structure and function, even within the same organism. The human body, for example, has more than 200 different types of cells, each with a specialized
Water movement in the xylem Water moves from roots to leaves through the xylem. But how? Hypotheses: 1. Capillary action - water will move upward in
Transport in Plants Two Transport Processes Occur in Plants 1. Carbohydrates carried from leaves (or storage organs) to where they are needed (from sources to sinks) 2. Water transported from roots to
2. Which type of macromolecule contains high-energy bonds and is used for long-term energy storage?
Energy Transport Study Island 1. During the process of photosynthesis, plants use energy from the Sun to convert carbon dioxide and water into glucose and oxygen. These products are, in turn, used by the
BCOR 011 Exam 2, 2004
BCOR 011 Exam 2, 2004 Name: Section: MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1. According to the first law of thermodynamics, A. the universe
The Cell Teaching Notes and Answer Keys
The Cell Teaching Notes and Answer Keys Subject area: Science / Biology Topic focus: The Cell: components, types of cells, organelles, levels of organization Learning Aims: describe similarities and differences
THE HISTORY OF CELL BIOLOGY
SECTION 4-1 REVIEW THE HISTORY OF CELL BIOLOGY Define the following terms. 1. cell 2. cell theory Write the correct letter in the blank. 1. One early piece of evidence supporting the cell theory was the
Eukaryotic Cell Structure: Organelles in Animal & Plant Cells Why are organelles important and how are plants and animals different?
Why? Eukaryotic Cell Structure: Organelles in Animal & Plant Cells Why are organelles important and how are plants and animals different? The cell is the basic unit and building block of all living things.
CELL ANALOGY: AIRPORT. By: Joe Behrmann and Isaac Thompson
CELL ANALOGY: AIRPORT By: Joe Behrmann and Isaac Thompson MITOCHONDRIA Location: The Mitochondria of a cell is located in both plant and animal cells. They are found floating throughout the cell. Function:
Total body water ~(60% of body mass): Intracellular fluid ~2/3 or ~65% Extracellular fluid ~1/3 or ~35% fluid. Interstitial.
http://www.bristol.ac.uk/phys-pharm/teaching/staffteaching/sergeykasparov.htmlpharm/teaching/staffteaching/sergeykasparov.html Physiology of the Cell Membrane Membrane proteins and their roles (channels,
Chemistry B11 Chapter 6 Solutions and Colloids
Chemistry B11 Chapter 6 Solutions and Colloids Solutions: solutions have some properties: 1. The distribution of particles in a solution is uniform. Every part of the solution has exactly the same composition
Review of the Cell and Its Organelles
Biology Learning Centre Review of the Cell and Its Organelles Tips for most effective learning of this material: Memorize the names and structures over several days. This will help you retain what you
Plant and Animal Cells
Plant and Animal Cells a. Explain that cells take in nutrients in order to grow, divide and to make needed materials. S7L2a b. Relate cell structures (cell membrane, nucleus, cytoplasm, chloroplasts, and
THE LIVING CELL. Cells also have variety of shapes. Plant cells are often rectangular or polygonal, while egg cells are usually spherical.
THE LIVING CELL A Tour of the cell The cell is the smallest and the basic unit of structure of all organisms. There are two main types or categories of cells: prokaryotic cells and eukaryotic cells. Prokaryotic
Osmosis. Evaluation copy
Osmosis Computer 5 In order to survive, all organisms need to move molecules in and out of their cells. Molecules such as gases (e.g., O 2, CO 2 ), water, food, and wastes pass across the cell membrane.
Harvesting Energy: Glycolysis and Cellular Respiration. Chapter 8
Harvesting Energy: Glycolysis and Cellular Respiration Chapter 8 Overview of Glucose Breakdown The overall equation for the complete breakdown of glucose is: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ATP The
Photosynthesis. Chemical Energy (e.g. glucose) - They are the ultimate source of chemical energy for all living organisms: directly or indirectly.
Photosynthesis Light Energy transduction Chemical Energy (e.g. glucose) - Only photosynthetic organisms can do this (e.g. plants) - They are the ultimate source of chemical energy for all living organisms:
pathway that involves taking in heat from the environment at each step. C.
Study Island Cell Energy Keystone Review 1. Cells obtain energy by either capturing light energy through photosynthesis or by breaking down carbohydrates through cellular respiration. In both photosynthesis
Cellular Respiration: Practice Questions #1
Cellular Respiration: Practice Questions #1 1. Which statement best describes one of the events taking place in the chemical reaction? A. Energy is being stored as a result of aerobic respiration. B. Fermentation
Week 1 EOC Review Cell Theory, Cell Structure, Cell Transport
Week 1 EOC Review Cell Theory, Cell Structure, Cell Transport Benchmarks: SC.912.L.14.1 Describe the scientific theory of cells (cell theory) and relate the history of its discovery to the processes of
Transmembrane proteins span the bilayer. α-helix transmembrane domain. Multiple transmembrane helices in one polypeptide
Transmembrane proteins span the bilayer α-helix transmembrane domain Hydrophobic R groups of a.a. interact with fatty acid chains Multiple transmembrane helices in one polypeptide Polar a.a. Hydrophilic
Exchange and transport
Exchange and transport Examples of things which need to be interchanged between an organism and its environment include: Respiratory gases Nutrients Excretory products Heat This exchange can take place
Engage: Brainstorming Body Systems. Record the structures and function of each body system in the table below.
Engage: Brainstorming Body s Record the structures and function of each body system in the table below. Body Nervous Circulatory Excretory Immune Digestive Respiratory Skeletal Muscular Endocrine Integumentary
Advanced Subsidiary GCE Biology
Advanced Subsidiary GCE Biology Unit F214 - Communication, Homeostasis and Energy - High banded OCR has produced these candidate style answers to support teachers in interpreting the assessment criteria
Cells are tiny building blocks that make up all living things. Cells are so small that you need a microscope to see them.
FC01 CELLS s are tiny building blocks that make up all living things. s are so small that you need a microscope to see them. ANIMAL CELL PLANT CELL This is the control centre of the cell. It contains chromosomes
Connexions module: m46021 1. The Cell Membrane. OpenStax College. Abstract. By the end of this section, you will be able to:
Connexions module: m46021 1 The Cell Membrane OpenStax College This work is produced by The Connexions Project and licensed under the Creative Commons Attribution License 3.0 By the end of this section,
Energy Production In A Cell (Chapter 25 Metabolism)
Energy Production In A Cell (Chapter 25 Metabolism) Large food molecules contain a lot of potential energy in the form of chemical bonds but it requires a lot of work to liberate the energy. Cells need
AP BIOLOGY 2006 SCORING GUIDELINES. Question 1
AP BIOLOGY 2006 SCORING GUIDELINES Question 1 A major distinction between prokaryotes and eukaryotes is the presence of membrane-bound organelles in eukaryotes. (a) Describe the structure and function
7.2 Cells: A Look Inside
CHAPTER 7 CELL STRUCTURE AND FUNCTION 7.2 Cells: A Look Inside Imagine a factory that makes thousands of cookies a day. Ingredients come into the factory, get mixed and baked, then the cookies are packaged.
Cell Structure and Function
CHAPTER 3 CELL STRUCTURE AND FUNCTION Vocabulary Practice cell theory vacuole concentration gradient cytoplasm lysosome osmosis organelle centriole isotonic prokaryotic cell cell wall hypertonic eukaryotic
OSMOSIS AND DIALYSIS 2003 BY Wendy Weeks-Galindo with modifications by David A. Katz
OSMOSIS AND DIALYSIS 2003 BY Wendy Weeks-Galindo with modifications by David A. Katz OSMOSIS Osmosis is the reason that a fresh water fish placed in the ocean desiccates and dies. Osmosis is the reason
Chapter 1: Life Processes
The human body is composed of countless millions of units called cells. In an animal like a human there are many different types of cells, with different structures. They are specialised so that they can
Version 1.0. General Certificate of Education (A-level) June 2011. Biology BIOL1. (Specification 2410) Unit 1: Biology and Disease. Final.
Version 1.0 General Certificate of Education (A-level) June 2011 Biology BIOL1 (Specification 2410) Unit 1: Biology and Disease Final Mark Scheme Mark schemes are prepared by the Principal Examiner and
Cells. Structure, Function and Homeostasis
Cells Structure, Function and Homeostasis Characteristics of Cells Basic unit of life anything alive is made of cells Plasma membrane (skin) that separates them from the environment. Skeletonsfor protection
Chapter 2: Cell Structure and Function pg. 70-107
UNIT 1: Biochemistry Chapter 2: Cell Structure and Function pg. 70-107 Organelles are internal structures that carry out specialized functions, interacting and complementing each other. Animal and plant