* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 4 Cells and Their Environment
Survey
Document related concepts
Cell nucleus wikipedia , lookup
Cytoplasmic streaming wikipedia , lookup
Extracellular matrix wikipedia , lookup
Membrane potential wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cell culture wikipedia , lookup
Cell growth wikipedia , lookup
Signal transduction wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell membrane wikipedia , lookup
Transcript
Chapter 4 Cells and Their Environment Section 1 Passive Transport I. Diffusion 1. Cells maintain ___________ by controlling the movement of substances across their cell membrane. 2. Cells use __________ to transport some substances across the cell membrane. Other substances move across the ___________ _____________ without any use of energy by the cell. A. Random Motion and Concentration 1. _____________ ____________ movement across the cell membrane that does not require energy. Ex. __________ (see figure 1) 2. _____________ ___________ - a difference in the concentration of a substance across a space. Ex. ________________________________ _______________________________________________ Illustrate 3. Equilibrium – ________________________________________ ______________________________________________________ Ex. __________________________________________. Illustrate B. Movement of Substances 1. ________________ of a substance in a solution also move around randomly. 2. If there is a concentration gradient in the solution, the ________ _____________________________________________________ _____________________________________________________. 3._________________ - is the movement of a substance from an area of high concentration to an area of lower concentration caused by the random motion of particles of the substance. Illustrate 4. Many substances, such as molecules and ions dissolved in the _________ and in the fluid outside cells, _____________________________________ ______________________________________. Illustrate 5. Substances must be able to pass across the ___________________ for diffusion to take place. 6. The cell membrane is _________________________ to substances. 7. Why can certain substances move across the cell membrane and others can’t?______________________________________________________ ____________________________________________________________ ____________________________________________________________ II. Osmosis 1. __________________________ are small and can diffuse through the cell membrane. 2.____________ - is the diffusion of water through a selectively permeable membrane. Illustrate 3. Like other forms of ________________, osmosis involves the movement of a ________________________________________________________. 4. If the solutions on either side of the cell membrane have different concentrations of dissolved particles, they will also have ________________ ______________________________________________________________. 5. Osmosis will occur as free water molecules move into the solution with the ______________________________________________________________. 6. The direction of water movement across the cell membrane depends on the relative concentration of free water molecules in the ____________________ ________________________________. 7. There are 3 possibilities for the direction of water movement. a. Hypertonic Solution – when the fluid outside the cell has a _________ __________________________________________________________ __________________________________________________________ The cell _______________. Illustrate b. Hypotonic Solution – if the fluid outside the cell cell has a _________ __________________________________________________________ __________________________________________________________ The cell _________________. Illustrate c. Isotonic Solution- if the cytoplasm and the fluid outside the cell _____ __________________________________________________________ __________________________________________________________ This results in no net movement of water across the cell membrane and the cell stays the same size – a ________________ There is no change in ________ ____________. Illustrate 8. If left unchecked, the swelling caused by a hypotonic solution could cause a ______________________________. 9. What do plant cells have that prevent the cell from expanding too much? ___________________________________ III. Crossing the Cell Membrane 1. __________________________________ can pass across the cell membrane when aided by transport proteins. 2. Transport proteins called ____________ for ions and polar molecules. 3. Each channel allows only a _________________________ __________________________________________________ Illustrate A. Diffusion Through Ion Channels 1. Ions such as ___________________________ are involved in many important ___________________. Ex. _________________ _____________________________________________________ 2_______________________________ – a transport protein through which ions can pass. This is a type of _______________ ___________________. No use of _____________is required because ions move down their concentration gradient. B. Electrical Charge and Ion Transport 1.The movement of a _____________________________, such as an ion, across the cell membrane is influenced by the particles ______________________________________________ charge. 2. The inside of a typical cell is _________________________ with respect to the outside of the cell. Opposite charges attract and like charges ___________________. Illustrate 3. A more _____________________ charged ion outside the cell is more likely to diffuse into the cell. C. Facilitated Diffusion 1. ______________________________ – a transport protein that can bind to a specific substance on one side of the cell membrane, carry the substance across the cell membrane, and _____________ _____________________________________________________. 2. Facilitated diffusion – _______________________________ __________________________, such as amino acids and sugars – down their concentration gradient. This is a type of passive transport. Draw figure 4 page 80.