Lecture 11: Moving Molecules

Question 1

Membranes are mainly made up of what?

Answer 1

lipids and proteins; phospholipid bilayer with proteins embedded in it

Question 2

Is the outer part of membrane hydrophobic or hydrophilic?

Answer 2

hydrophilic

Question 3

is the membrane fluid or rigid and what does it mean?

Answer 3

the membrane is fluid; parts of the membrane move around in the membrane as well, this leaves space for stuff to come into the membrane but not everything; meaning it is semi permeable

Question 4

What are the things that cant go in and out of the membrane freely?

Answer 4

things that have a charge and large molecules
examples: water, sugar, ions, proteins

Question 5

What are things that can go in and out of the membrane freely?

Answer 5

oxygen and carbon dioxide

Question 6

What is included in passive transport?

Answer 6

diffusion: simple diffusion, facilitated diffusion, osmosis

Question 7

What is diffusion?

Answer 7

movement of a population of molecules from an area of high concentration to an area of low concentration: DOWN concentration gradient and continues until equilibrium is reached

Question 8

What is an example of something that simply diffuses across the membrane and explain it!

Answer 8

oxygen and if the cell is performing cellular respiration it is constantly using up the oxygen meaning oxygen will constantly be moving into the cell

Question 9

What is facilitated diffusion?

Answer 9

when molecules move down the concentration gradient with the help of a transport protein
- channel/carrier protein

Question 10

What is an example of a thing that uses facilitated diffusion?

Answer 10

Na, Cl

Question 11

What is osmosis?

Answer 11

diffusion of water;water diffuses down the concentration gradient

Question 12

the side that has a higher solute concentration will have a higher or lower water concentration?

Answer 12

lower water concentration

Question 13

What does tonicity mean?

Answer 13

the ability of a surrounding solution to cause a cell to gain or lose water

Question 14

What is a hypertonic solution?

Answer 14

a hypertonic solution is one that has a higher concentration of solutes in the solution vs the inside of the cell WATER LEAVES CELL

Question 15

What is an isotonic solution?

Answer 15

when the concentration of solutes is equal in the surrounding solution and inside the cell, equal flow of water in and out of cell

Question 16

What is a hypotonic solution?

Answer 16

When the surrounding solution has a lower concentration of solutes than the inside of the cell WATER WILL ENTER THE CELL

Question 17

Passive transport vs active transport ball example?

Answer 17

passive transport is like a ball going down the slide with no energy and active transport is ball going up the slide , energy is needed

Question 18

What is active transport?

Answer 18

movement of a population of molecules from a low concentration to a high concentration AGAINST concentration gradient

Question 19

what does active transport need?

Answer 19

selectively permeable membrane, atp, and transport proteins

Question 20

What is a sodium potassium pump?

Answer 20

na + k+ pump: for every one molecule of atp, 3 na ions pumped out and 2 k ions pumped in

Question 21

Bulk transport?

Answer 21

requires lots of energy: move in and out vesicles

Question 22

What is exocytosis vs endocytosis?

Answer 22

exocytosis is movement out of the cell and endocytosis is movement into the cell