Chapter 5: Cell Transport

Question 1

What are the parts of a membrane?

Answer 1

1. Lipids
2. Proteins
3. Carbohydrates
4. Cholesterol

Question 2

What do the lipids do in the cell membrane?

Answer 2

phospholipids (selectively permeable) - lets some stuff pass and others are denied

Question 3

What do proteins do in the cell membrane?

Answer 3

act like a door to let in big molecules

Question 4

What do carbohydrates do in the cell membrane?

Answer 4

act as identifiers

Question 5

What does cholesterol do in the cell membrane?

Answer 5

keeps the consistency of the membrane consistent when the temperature changes

Question 6

What do cell membranes do?

Answer 6

help maintain homeostasis controlling what substances may enter or exit the cell

Question 7

What is passive transport?

Answer 7

some molecules can enter the cell without any input of ATP (energy); molecules move from high to low concentration; go with the concentration gradient

Question 8

What are the 3 kinds of passive transport?

Answer 8

1. Diffusion
2. Facilitated diffusion
3. Osmosis

Question 9

What is diffusion?

Answer 9

the movement of molecules in an area of high concentration to low concentration.

Question 10

What is the concentration gradient?

Answer 10

the difference in the concentration of molecules across a distance

Question 11

At what point will molecules stop diffusing?

Answer 11

when they reach equilibrium

Question 12

What is equilibrium?

Answer 12

the equal concentration of molecules throughout

Question 13

What is let in through the cell membrane?

Answer 13

small, polar molecules (like O2 and CO2)

Question 14

What is stopped at the cell membrane?

Answer 14

large (glucose C6H12O6), non-polar molecules (lipids) like ions Na+ Cl-

Question 15

What is facilitated diffusion?

Answer 15

a process by which large molecules must enter the cell via a carrier protein (happens to glucose)

Question 16

What determines what molecule a carrier protein transports?

Answer 16

shape

Question 17

How are ion channels triggered to open?

Answer 17

stretching the membrane, electrical signals, or chemical in the cytoplasm

Question 18

What is osmosis?

Answer 18

the passive transport of water across a membrane

Question 19

What causes osmosis?

Answer 19

when particles cannot move to reach equilibrium, the water will move to equalize the ratio between the number of particles and the number of water molecules

Question 20

What’s the rule for salt and water?

Answer 20

wherever salt is, water will follow

Question 21

What are the 3 directions of water movement?

Answer 21

1. Hypotonic
2. Hypertonic
3. Isotonic

Question 22

What is hypotonic movement?

Answer 22

more solutes (salt) inside the cell than outside the cell; water will flow in; cell’s volumes increases

Question 23

What is hypertonic movement?

Answer 23

more solutes (salt) outside the cell than inside the cell; water flows out of the cell; cell’s volume decreases

Question 24

What is isotonic movement?

Answer 24

solutes (salt) are equal inside and outside the cell; water flows equally; volume stays the same

Question 25

What is turgor pressure?

Answer 25

happens in a hypotonic environment where plants bring water into their roots and the water adds pressure to the cell wall

Question 26

What is cytolic pressure (cytolisis)?

Answer 26

happens when animal cells are in hypotonic environments and the cell swells so much that it bursts (pressure from the cytoplasm)

Question 27

What is plasmolic pressure (plasmolysis)?

Answer 27

happens when animal cells are in a hypertonic environment and when water flows out of the cell, it is crushed by the external pressure

Question 28

What do contractile vacuoles do?

Answer 28

they are a specialized organelle that pumps out extra water; a part of organisms in a hypotonic environment (water is flowing in them all the time) so that they don't explode

Question 29

What is active transport?

Answer 29

happens when cells need to move materials from an area of low concentration to high concentration, which requires ATP (against concentration gradient)

Question 30

What are pumps?

Answer 30

transport proteins that pump materials against the concentration gradient

Question 31

What is an example of a pump?

Answer 31

sodium-potassium pump: 3 Na go in, 2 K come out

Question 32

Why do pumps need to be shielded from the lipid tails?

Answer 32

polarity

Question 33

What is exocytosis?

Answer 33

process by which substances in the cell are released by a vesicle; once the golgi has modified the protein, it will create a vesicle that will move through the cytoplasm and then become a part of the membrane, releasing the substance

Question 34

What is endocytosis?

Answer 34

process by which substances enter the cell

Question 35

What are the 2 types of endocytosis?

Answer 35

1. phagocytosis - solids enter the cell 2. pinocytosis - liquids enter the cell

Question 36

What are phagocytes (cells)?

Answer 36

filled with enzymes and break up bacteria

Question 37

What kind of cell transport are protein channels and ion channels a part of?

Answer 37

facilitated diffusion

Question 38

Which solution would be isotonic for a human cell?

Answer 38

saline

Question 39

Plants' roots are full of

Answer 39

salt

Question 40

Exo- and Endo-cytosis are an example of what kind of cell transport?

Answer 40

active