Chapter 4.3 The Cell In Its Environment

Question 1

what does selectively permeable mean

Answer 1

some substances can pass through the cell membrane while others cannot

Question 2

what is diffusion

Answer 2

the process in which molecules move across the cell membrane from an area of high concentration to low concentration

Question 3

what is osmosis

Answer 3

osmosis is the diffusion of water molecules through a selectively permeable membrane

Question 4

what happens when a freshwater fish is placed in a saltwater acquarium

Answer 4

the high concentration of H20 is in the fish, so the fish’s water molecules will go into the aquarium, causing the fish to shrink

Question 5

What happens when a saltwater fish is placed in a fresh water aquarium?

Answer 5

The high concentration of water molecules is in the aquarium so when the fish is placed in the aquarium the water molecules will go through the fishes cell membrane which will cause the fish to expand.

Question 6

What is passive transport?

Answer 6

Passive transport is the movement of dissolved materials downhill through the cell membrane without using energy

Question 7

What is active transport?

Answer 7

Active transport is the movement of materials through a cell membrane using the cells energy while going uphill.

Question 8

What do transport proteins do?

Answer 8

Transport proteins in the cell membrane pickup molecules outside the cell and carry them in using energy.

Question 9

How does transport by engulfing work?

Answer 9

First the cell membrane encloses on a particle. Once the particle is engulfed the cell membrane wraps around the particle and forms a vacuole within the cell. The cell must use energy in this process.