2. How does the process of diffusion and the structure of the cell membrane help the cell maintain homeostasis? Como afectada la difusion a la membrana celular y la homeostasis ?

3. It’s all about concentration! Todo comienza con la concentracion de una substancia! Concentracion- Cantidad de soluto! Soluto- lo que disuelves solvente- material en el que toma lugar (agua)

4. What is a concentration gradient? ¿Qué es un gradiente de concentración? The difference in concentration between a region of high concentration and a region of lower concentration. La diferencia de concentración entre una región de alta concentración y una región de menor concentración.

5. What is diffusion? Que es difusion? The net movement of particles from where they are more concentrated to where they are less concentrated. Movimiento de las particulas desde un area de mayor concentracion a un area de menor. Concentration-The amount of a substance Concentracion- cantidad de una substancia

6. What is the end result of diffusion? Cual es el resultado de la difusion? The number of particles are now evenly distributed! Como las particulas se mueven constantemente, se mezclan hasta que la distribucion sea uniforme! This is called: Dynamic Equilibrium Esto se llama Equilibrio Dinamico

7. Dynamic Equilibrium

8. An illustration of diffusion:

9. Two Conditions for Diffusion: Para que suceda la difusion: 1)There must be a concentration Gradient. Debe existir una diferencia en la concentracion 2) There must be no barrier blocking the movement of particles. No puede haber una barrera

10. The cell membrane is selectively permeable. It allows some substances to cross the membrane more easily than others and blocks the passage of other substances altogether. La membrana celular es selectivamente permeable. Permite que algunas sustancias cruzen la membrana más facilmente mientras bloquea el paso de otras sustancias.

11. Small molecules are more likely to get through the cell membrane compared to big molecule Moléculas pequeñas tienen más probabilidades de atravésar la membrana célular que la moléculas grandes

12. Cell membranes must help organism maintain HOMEOSTASIS by controlling what substances enter or leave the cells. To stay alive, a cell must exchange materials such as food, water, and waste with its environment. Las membranas celulares debe ayudar a organismo mantener HOMEOSTASIS mediante el control de qué sustancias entran o salen de las células. Para permanecer vivo, una célula debe intercambiar materiales tales como alimentos, agua y residuos con el medio ambiente.

13. What is the main job of the cell membrane? Cell membranes helps organisms maintain _____________ by controlling what substances may enter or leave cells To stay alive, a cell must exchange materials such as food, water, & wastes with its environment HOMEOSTASIS & TRANSPORT

14. Which structure may function in the recognition of chemical signals? Que estructura va a responder a una senal quimica? (1) A (3) C (2) B (4) D The diagram to the right represents a portion of a cell membrane.

15. State one possible reason why molecule A could diffuse across the membrane of the cell but molecule B could not. Porque la molecula A puede pasar a travez de la membrana celular y la B no? Two molecules, A and B, and their distribution inside and outside of a cell are represented in the diagram to the right.