TOPIC VII: Cell Structure and Function Describe the processes that move molecules in living systems and their importance: diffusion, osmosis, and active transport. Include the direction of movement, types of substances moved, and energy that drives each process.

How Cells Communicate

P.R.S Iso- Equal Hypo- Less Than Hyper- More Than Semi- Part

Describe Transport Mechanisms A cell is a busy place; similar to a factory Raw materials are constantly being delivered, products are being made, and waste products are generated. There must be methods for moving substances within as well as in and out of the cell.

Nucleolus –Ribosomes-Proteins Review Cell Parts DNA Storage & Packaging ATP Nucleolus –Ribosomes-Proteins

Homeostasis The tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, regardless of the outside changing conditions. Ex: Body Temperature, Fluids, Sugar Levels.

A lipid bilayer with protein molecules dispersed within it..

Lipid-soluble (non-polar) substances pass through the membrane. Fluid Mosaic Model Polar Non-Polar Lipid-soluble (non-polar) substances pass through the membrane.

Protein channels that provide passage for certain molecules. Low to High ATP

Diffusion - movement of molecules from an area of higher concentration to an area of lower concentration.

What Is Simple Diffusion? https://www.youtube.com/watch?v=VY0mZUDvbH4

When the molecules are even throughout a space - it is called EQUILIBRIUM

Concentration gradient, the difference in the number of molecules between two areas. Equilibrium

How does temp. effect diffusion rate? When the molecules are even throughout a space - it is called EQUILIBRIUM https://www.youtube.com/watch?v=Peg1yaB2bsk How does temp. effect diffusion rate?

Permeability Examples in the room? Permeable- everything Semi-Permeable- somethings Non-Permeable- nothing Examples in the room?

Permeability S e l e c t i v e l y p e r m e a b l e. Non-Permeable.

Osmosis- the diffusion of water through a selectively permeable membrane http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

This is also why you get thirsty after eating something salty. Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is also why you get thirsty after eating something salty.

How Osmosis Affects Cells

Solute – substance to be dissolved Solvent- dissolving liquid Ex: Salt Solvent- dissolving liquid Ex: Water

Osmosis- diffusion of water. Diffusion and Osmosis are both types of PASSIVE TRANSPORT - that is, no energy is required. Osmosis- diffusion of water.

Active Transport: a means of crossing a membrane : requires energy

ACTIVE TRANSPORT this type of transport requires that the cell use energy, because substances are moving against the concentration gradient. ATP Low Conc. High Conc. Active Transport Transport Protein

No Energy Energy LOW to HIGH https://www.youtube.com/watch?v=vKGN_Zhz8AY No Energy Energy LOW to HIGH

Salt is a solute, when it is concentrated inside or outside the cell, it will draw the water in its direction. This is also why you get thirsty after eating something salty. Why do people use salt to preserve food?

-The word "HYPER" means more. -There are more solute (salt) molecules outside the cell, which causes the water to be sucked in that direction. -Cells will shrink.

Endocytosis - cell takes in large particles by engulfing them

Endocytosis - cell takes in large particles by engulfing them

Exocytosis - cell gets rid of particles, opposite of endocytosis

Practice Questions W hat A nswer R eason

1. The cell membrane of the red blood cell will allow water, oxygen, and carbon dioxide to pass through. Because other substances are blocked from entering, this membrane is called A. perforated B. semi-permeable C. non-conductive D. permeable

2. A person with swollen gums rinses his mouth with warm salt water, and the swelling decreases. Which of the following has occurred? A. The swollen gums have absorbed the saltwater solution. B. The saltwater solution lowers the temperature of the water in the gums. C. The salt in the solution has moved against the concentration gradient. D. The water in the gums has moved out due to the high concentration of salt in the solution.

3. Cells need to bring in molecules to carry out cellular processes 3. Cells need to bring in molecules to carry out cellular processes. Often, this requires moving the molecules across the cell membrane against the concentration gradient. How do these molecules get into the cell?  A. passive transport by diffusion B. active transport using ATP  C. passive transport by osmosis D. phagocytosis

4. Sodium-potassium pumps, endocytosis, and exocytosis all involve active transport. Which of the following is a characteristic of active transport? a. It involves facilitated diffusion. b. It requires energy from the cell. c. It relies on vesicles that often function as pumps. d. It moves substances with a concentration gradient

5. Your lungs are constantly exchanging oxygen and carbon dioxide between your body cells and your blood cells by diffusion. As you exercise intensely, your body temperature increases slightly. How does this affect the process of diffusion? a. The rate of diffusion increases due to your slightly higher body temperature b. The rate of diffusion decreases due to your slightly higher body temperature. c. The rate of diffusion is unaffected by changes in temperature. d. Diffusion stops completely during periods of over-exertion

6. Which is an important function of the cell structure in this model? a. Controlling passage of materials b. Packaging cell products for export c. Transferring hereditary material to offspring d. Preventing a cell from bursting due to osmosis

7. Some peeled pieces of apple were placed in distilled water and some in very salty water. The cells in the apple pieces will — a. lose water in both solutions b. gain water in both solutions c. lose water in the distilled water and gain water in the salty water d. gain water in the distilled water and lose water in the salty water

a. phagocytosis b. pinocytosis c. diffusion d. cyclosis 8. The diagram below shows the same type of molecule in area A and area B. With the passage of time, some molecules move from area A to area B. This movement is the result of the process of. a. phagocytosis b. pinocytosis c. diffusion d. cyclosis

Starch turns blue-black in the presence of iodine solution Starch turns blue-black in the presence of iodine solution. A selectively permeable dialysis tube containing a starch solution is placed into a beaker of iodine solution.

9. If the dialysis sac is permeable only to water and iodine, what will the solutions in the beaker and the sac look like after two hours? A. The iodine solution in the beaker will turn blue-black; the starch solution will not change. B. The starch solution in the dialysis sac will turn blue-black; the iodine solution will not change. C. Neither solution will turn blue-black. D. Both solutions will turn blue-black.

10. Which of these processes is demonstrated by the above experiment shown in the diagram? A. Cellular respiration B. Active transport C. Endocytosis D. Diffusion