Chapter 5 review

Question 1

What is the role of the plasma membrane?

Answer 1

separate intracellular fluid and extracellular fluid
regulate movement in and out of the cell

Question 2

What factors affect membrane fluidity?

Answer 2

unsaturated fatty acids - love water
cholesterol - fewer fluids
inc temperature - inc fluidity

Question 3

What two types of proteins are associated with membranes?

Answer 3

integral and peripheral proteins

Question 4

What are the names of lipids and proteins when they have a carbohydrate attached to them?

Answer 4

Glycolipids & Glycoproteins

Question 5

What are the components of a solution? How would you calculate the concentration of
a solution? What is osmolarity?

Answer 5

Solution: made up of solvents and solutes
Calculate: ___/mol
Osmolarity: concentration of all solute particles in solution

Question 6

Does passive membrane transport require ATP? What are the three types of passive membrane transport?

Answer 6

No ATP
examples: simple diffusion, facilitated diffusion, osmosis

Question 7

What is the definition of diffusion?

Answer 7

when molecules/ions go from an area of a high concentration to a low concentration

Question 8

What are the characteristics of solutes that determine whether or not they can pass across a phospholipid bilayer? Would you expect an amino acid to pass across?

Answer 8

Lipid solubility - must be non-polar
size of molecule
yes an amino acid can cross due to small size

Question 9

What are the two types of facilitated diffusion? What types of solutes, and what two types of proteins are involved? Is any input of energy needed?

Answer 9

Channel mediated diffusion and Carrier mediated diffusion
Carrier mediated: carrier alters shape for transport ex. sugars and amino acids
Channel mediated: substances diffuse through channels
leak channel open, gated channel: controlled by chemical or electrical signals ex. water, ions like salt

NO ENERGY IS NEEDED FOR EITHER

Question 10

Describe simple diffusion

Answer 10

Diffusion of molecules directly though the bilayer
- nonpolar ex gasses, steroid hormones, fatty acids

Question 11

What is the definition of osmosis? When does it occur? What direction does water move in? What is meant by osmotic pressure?

Answer 11

Diffusion of a solvent through a selectively permeable membrane
when: concentration of water differs on two sides of the membrane
Water moves from a more dilute to less dilute solution

Question 12

Why is osmosis important for homeostasis?

Answer 12

distribution of water and fluid ex. healthy indv ECF=ICF

Question 13

At equilibrium can both sides have the same osmolarity but different volumes?

Answer 13

yes

Question 14

Isotonic solutions

Answer 14

Same concentration of non-penetrating solutes inside the cell

Question 15

hypertonic solutions

Answer 15

higher concentration outside than inside of the cell makes cells shrink
ex. salt water

Question 16

Hypotonic solutions

Answer 16

higher concentration inside the cell inside than outside
cells will swell
ex. pure water

Question 17

How does active transport differ from facilitated diffusion?

Answer 17

movement of substances against the concentration gradient or movement of large substances
- ATP required

Question 18

What does active transport require:

Answer 18

membrane protein and energy

Question 19

Two types of active transport?

Answer 19

primary active transport
secondary active transport

Question 20

Primary active transport?

Answer 20

substance binds to a transmembrane protein
hydrolysis of ATP
Phosphorylation of transmembrane protein
protein changes shape
substance goes to other side

Question 21

Describe the sodium-potassium pump

Answer 21

3 sodium 2 potassium in
Atp binds with 3 na
Na binding causes ATP hydrolysis and pump changes shape
Na is released
K+ (potassium binds) and phosphate is released
Potassium in

Question 22

Describe secondary active transport

Answer 22

coupling - one subtance goes against and one goes down
energy through substance going down

Question 23

Symport transport

Answer 23

one direction

Question 24

Antiport transport

Answer 24

both directions

Question 25

What are the two types of vesicular transport?

Answer 25

ways to transport large particles
Endocytosis: substances move inside call
Exocytosis: substances moved outside cell

Question 26

By what 3 mechanisms are materials endocytosed?

Answer 26

Phagocytosis: cells engulf the large particle at once
Pinocytosis: cell gulps tiny fluid
receptor-mediated endocytosis: receptor proteins tell which substances to enter

Question 27

How are proteins exported from the cell, and what is this process called?

Answer 27

Exocytosis - transport to the ECF

Question 28

What are the two types of local signaling and the one type of long distance signaling called?

Answer 28

Local signaling:
paracrine: molecules released by cell acts on nearby cells
synaptic: nerve cell releasing neurotransmitters to a synapse

Long distance:
endocrine: endocrine cells releasing hormones into body fluids

Question 29

Ligands?

Answer 29

signaling molecules that bind to receptors

Question 30

Receptor? what are the 2 types:

Answer 30

Proteins in plasma membrane
- G protein coupled receptors (GPCRs)
- ligand-gated ion channels

Question 31

How do GCPRs work?

Answer 31

Ligand binds to GPCR
Gpcr activated changes shape
G protein binds to GPCR
GTP binds to G protein
G protein leaves GCPR and diffuses alng membrane
G protein binds enzyme and changes enzyme shape
cellular response occurs