Chapter5

Question 1

membranes composed mainly of

Answer 1

phospholipid bilayer 
also contians
-other lipids 
-proteins
-carbohydrates

Question 2

general properties of a phospholipid bilayer

Answer 2

1. self assembling in water
2. individual molecules are not static (fluid mosaic)
3. semi permable

Question 3

phospholipids are permeable to

Answer 3

hydrophillic molecules

small molescules

Question 4

phospholipids are impermeable to

Answer 4

large molecules

ions

Question 5

membrane proteins are held in membrane due to

Answer 5

their hydrophobic and hydrophillic nature

attachment to cytoskeleton

Question 6

membrane proteins

Answer 6

1. enzymes
2. carry signals
3. transport
4. cell recongnition
5. attach membrane to cytoskeleton

Question 7

movement across membranes: passive transport

Answer 7

diffusion- across a membrane-only occurs from an area of high concentration to an area of low concentration
does not require energy from the cell

Question 8

rate of transportation depends on

Answer 8

1. temp
2. concentration gradient
3. the ability to pass through the membrane

Question 9

materials not permeable to phospholipids may

Answer 9

pass through proteins (facilitated diffusion)

Question 10

osmosis

Answer 10

diffusion of water

water moves from an area of a low to high solute( dissolved substance) concentration

Question 11

isotonic

Answer 11

same salt concentration

Question 12

hypotonic

Answer 12

solution with a lower salt concentration

Question 13

hypertonic

Answer 13

solution with a higher salt concentration

Question 14

solutions with different salt concentration can

Answer 14

cause cells to lose or gain water

Question 15

organisms with cell walls can use what in cells to give them structure

Answer 15

water pressure and movement

Question 16

active transport

Answer 16

requires potential energy stored by the cell

Question 17

what is energy

Answer 17

the ability to do work

Question 18

energy is never created or destoryed but

Answer 18

it can be changed from one form to another

Question 19

4 forms energy important to living things

Answer 19

1. heat - living things cant make or convert this to other forms of energy
2. kinetic energy
3. potential energy:
   bonds in molecules, concentration gradients
4. light

Question 20

energy released from chemical reactions (from bonds) is used to:

Answer 20

1. change the shape of proteins
2. move molecules
3. create new bonds

Question 21

ATP

Answer 21

acts as a short term energy storage and transport unit

Question 22

2 types of active transport

Answer 22

1. transport against a concentration gradient
2. transport of impermeable substances
   both are accomplished by membrane bound proteins

Question 23

endosytosis and exocytosis

Answer 23

transport by movement of the membrane

used for bringing large molecules into and out of the cell

Question 24

cells involved in exocytosis have

Answer 24

golgi bodies