ppt 4

Question 1

Cell Membrane Functions:

a. Controls what __ and __ the cell to maintain an internal balance called __.

b. Provides __and __ for the cell

Answer 1

enters
exits
internal balance

homeostasis

protection

support

Question 2

What is the purpose of cellular
transport?

• Homeostasis depends upon __ of materials across the cell membrane.
  – Required materials must pass into the cells so they can be
  utilized.
• Ex. __ and __ for cellular respiration
  – Waste materials must pass out of the cells as they are produced
• Ex. The CO2
  produced as a waste product of __.
• The cell membrane regulates the passage of materials
  into and out of the cell.
  – Needed materials move in
  – Excess materials move out

Answer 2

appropriate movement

materials

oxygen

glucose

cellular respiration

Question 3

Types of Cellular Transport

• Passive Transport: cell does ____.
  1. __
  2. __
  3. __
• Active Transport: cell does __.
  1. __
  2. __
  3. __

Answer 3

not use energy

diffusion
facilitated diffusion
osmosis

use energy

protein pumps
endocytosis
exocytosis

Question 4

Passive Transport:

• cell uses no energy.
• molecules move ___.
• The random motion of molecules occurs along the __; i.e., molecules spread out from an area of __ to an area of __.

Answer 4

randomly

concentration gradient

high concentration

low concentration

Question 5

Types of Passive Transport
1. Diffusion – is the __ of molecules across a __ until they are __.

2. Facilitative Diffusion – diffusion with the help of __.
3. Osmosis – diffusion of __.

Answer 5

spreading out

cell membrane

equally concentrated

transport proteins

water

Question 6

Passive Transport:
1. Diffusion
* Diffusion: __ of particles from an area of __ to an area of __.

• Diffusion continues until all molecules are __ (__is reached).

Molecules will still move but stay spread out (__).

Answer 6

random movement

high concentration

low concentration

evenly spaced

equilibrium

net zero flow

Question 7

Facilitated diffusion: diffusion
of specific particles along the __ (High  Low) with the help of __ found in the __.

Answer 7

concentration gradient

transport proteins

membrane

Question 8

Facilitated diffusion: diffusion
of specific particles along the
concentration gradient (High  Low) with the help of transport proteins found in the membrane.

• Transport Proteins are __–
  they “select” only certain molecules to cross the membrane.
• Transports __ or __ molecules
  that cannot pass through the membrane on their own.
• __ is an example of a molecule that passes into the cell through facilitated diffusion.

Answer 8

specific

larger

charged

glucose

Question 9

Osmosis: diffusion of water
through a __ membrane.
* Water moves from a __
concentration of water to a __
concentration of water.

• Because water is so __ and in
  such __ the cell cannot control its movement through the cell membrane.

Answer 9

selectively permeable

high

low

small

abundance

Question 10

Water moves freely through __.

• Solute too large to move across.

– Solute: what is being __
– Solvent: what __ the solute

• In salt water the _ is the salt and the __is the water

Answer 10

pores

dissolved

dissolves

solute

salt

water

Question 11

Hypotonic Solution
Hypotonic: The solution has a __
of solutes and a __of water than
referent

Answer 11

lower concentration

higher concentration

Question 12

Isotonic Solution

Isotonic: The concentration of solutes in the solution is __ to the concentration of solutes __.

Result: Water moves __ in both directions and the cell remains same size! (__)

Answer 12

equal

inside the cell

equally

dynamic equilibrium

Question 13

How organisms deal with
osmotic pressure

• Bacteria and plants have __ that prevent them from overexpanding. In plants the pressure exerted on the cell wall is called __.
• A protist like the paramecium has contractile vacuoles that collect water flowing in and pump it out to prevent them from over expanding.
• Salt-water fish pump salt out of their specialized gills so they do not dehydrate.
• Animal cells are bathed in blood. Kidneys keep the blood __by removing excess salt and water

Answer 13

cell walls

turgor pressure

isotonic

Question 14

Active Transport

• Requires the cell to use __.
• Actively moves molecules to where they are needed.
• Molecules move __from an area of __ to an area of __.

Answer 14

energy

against the concentration gradient

low concentration

high concentration

(Low  High)

Question 15

1. Protein Pumps -__ that
   require __ to do work

• Example: Sodium / Potassium pumps are important in nerve responses.

Protein changes shape to move
molecules: this requires energy

Answer 15

transport proteins

energy

changes shape

Question 16

2. Endocytosis: taking bulky
   material __ a cell by forming a
   __.

• Uses energy.
• Cell membrane in-folds around food particle.
• “cell eating” forms food __&
  digests food.
• This is how white blood cells
  eat bacteria!

Answer 16

into

vesicle

in-folds

vacuole

Question 17

A cell can import and export large materials or large amounts of material in __ during __ and ___.

• Cells use energy to transport material in __.
• __ is the process of __ material __ the cell.

__is the process of __material __the
cell.

Answer 17

vesicles

endocytosis

exocytosis

vesicles

taking

into

expelling

from

Question 18

Exocytosis: Forces material
out of cell in bulk
* __ surrounding the material __ with __.
* Cell changes shape – requires __

• Ex: __ or __ released from cell

Answer 18

membrane

fuses

cell membrane

energy

hormones

wastes