Chapter 3

Question 0

What are the Major components of a cells membrane?

Answer 0

1) phospholipids
2) cholesterol gives it strength
3) carbohydrates on the outside

Question 1

What are the 3 parts of a cell?

Answer 1

1) plasma membrane- outer boundary of a cell
2) cytoplasm- intercellular fluid
3) nucleus- house genetic info(DNA) of a cell

Question 2

Describe phospholipids:

Answer 2

• Hydrophilic head attached to water

- Hydrophobic tails made up of 2 fatty acid chains.

Question 3

How do substances move across the cell membrane?

Answer 3

They move across actively and passively

Question 4

What is passive transport?

Answer 4

No energy is used from the cell. There are 2 passive processes:

1) diffusion
2) filtration

Question 5

What is active transport?

Answer 5

The cell uses ATP to allow substances to cross the membrane.

Question 6

What is diffusion?

Answer 6

It’s an passive transport. It’s a tendency of molecules or ions to move from an area of high concentration to low concentration. The driving force is kinetic energy.

Question 7

How is the speed of diffusion effected?

Answer 7

It’s effected by the size of molecules and the temperature.
Smaller=faster
Warmer=faster

Question 8

How can ions and molecules cross the cell membrane?

Answer 8

It can cross if it’s:

1) lipid solvable
2) non polar
3) assisted by carrier molecules

Question 9

What is simple diffusion?

Answer 9

Movement of particles from a high concentration to low concentration without an input of energy.

Question 10

What is facilitated diffusion?

Answer 10

Substances move from a high concentration to low concentration without energy input.It’s a type of passive transport process. The transported substance binds to a protein carrier in the membrane and is ferried across. Or it can move through a water filled protein channel.

Question 11

What are the 2 types of channels?

Answer 11

1) leakage channel- it’s always open

2) gated channel- has gates that open and close by chemical or electrical signals

Question 12

What is osmosis?

Answer 12

Diffusion of water through a selectively permeable membrane.

Question 13

What is osmolarity?

Answer 13

Total concentration of all solute particles in a solution.

Question 14

What is tonicity?

Answer 14

Ability oF a solution to change the shape or tone of cells by altering the cells internal water volume.

Question 15

What are the 3 forms of tonicity?

Answer 15

1) isotonic solution
2) hypotonic solution
3) hypertonic solution

Question 16

How does an isotonic solution effect the cell?

Answer 16

It doesn’t because the osmolarity of the solution is equal to the osmolarity of the cell.

Question 17

How does a hypotonic solution effect the cell?

Answer 17

There is a lower concentration of non penetrating solute compared to the cell. Water will move into the cell causing it to swell.

Question 18

How does a hypertonic solution effect the cell?

Answer 18

There is a higher concentration of non penetrating solute than inside the cell. The cell will lose water causing it to shrink.

Question 19

What is active transport?

Answer 19

When the cell uses energy to move solutes across the membrane.solutes are moved from a high concentration to a low concentration.

Question 20

What are the 2 types of active transport?

Answer 20

1) primary active transport- breaks down ATP and turns it into adp
2) secondary active transport- is driven by energy that is stored in ionic gradients created by primary active transport pumps.

Question 21

What is symport system?

Answer 21

It transport 2 substances in the same direction. Either into or out of a cell.

Question 22

What is the antiport system?

Answer 22

The antiport system moves substances in opposite directions.

Question 23

What are the functions of carbohydrates?

Answer 23

The major function is to provide a ready, easily used source of cellular fuel (energy). Most cells can use only a few simple sugars, Glucose is at the top of the “cellular menu”. Glucose is used during oxidation reduction rxns to be broken down and oxidized within cells.