Ch. 5 Membrane Dynamics

Question 1

ECF

Answer 1

1/3 of body water volume

Blood plasma+interstitial fluid

Question 2

ICF

Answer 2

2/3 of body water volume

Question 3

Diffusion

Answer 3

Movement of solutes down the gradient

-can be simple or facilitated (needs transport protein)

Question 4

Osmosis

Answer 4

Movement of water to equalize solute concentration

-Moves from hypotonic to hypertonic

Question 5

Protein Pump

Answer 5

Direct Active transport

• uses exergonic reaction to drive transport
  ex: Na/K Pump

Question 6

Concomitant Transport

Answer 6

Indirect (secondary) Active Transport
Uses diffusion of another molecule to drive transport
(ex: Na/glucose symporter uses diffusion of Na into the cell to drive import of glucose)

Question 7

Vesicular Transport

Answer 7

Indirect (Secondary) Active Transport
Membrane bound compartments interact at plasma membrane
-Endo- Exo- Phago- cytosis

Question 8

Na/glucose symporter

Answer 8

Indirect (Secondary) Active Transport

Uses diffusion of Na into the cell to drive import of glucose

Question 9

Molarity

Answer 9

Concentration of a solution (moles per liter)

Question 10

Osmolality

Answer 10

Number of osmotically active particles per liter (OsM)

Question 11

Dissociation of Particles

Answer 11

Affects osmolality

1M NaCl=1OsM Na and 1 OsM Cl

Question 12

Osmometer

Answer 12

Measures osmolality

Question 13

Membrane Receptors

Answer 13

Protein Mediated Transport

Lingand binding domain on outside of cell -> triggers response

Question 14

Carrier Proteins

Answer 14

Protein Mediated Transport

Change shape

Question 15

Protein Mediated Transport Devices

Answer 15

• Channel Protein (open and gated)
• Carrier Proteins
• Membrane Receptors

Question 16

Phagocytosis

Answer 16

Actin microfilaments and myosin motor proteins of cytoskeleton change shape of membrane
-Vesicle fuses with lysosomes to degrade contents

Question 17

Exocytosis

Answer 17

-Increase in intracellular Ca
-Rabs facilitate plasma membrane docking
SNARES facilitate membrane fusion

Question 18

Endocytosis (receptor-mediated)

Answer 18

Receptor and clathrin coated pits trigger formation of vesicle

Question 19

Endocytosis (caveolae)

Answer 19

Involve lipid rafts, receptors, and caveolins

• caveolins create caveolus shape
• viral infections

Question 20

Hypercholesterolemia

Answer 20

Receptor-mediated cholesterol transport (endocytosis) with too few receptors

Question 21

Apical Membrane

Answer 21

Faces inside of organ

-microvilli increase surface area for more transport proteins

Question 22

Basolateral Membrane

Answer 22

Faces ECF

-separated from apical membrane by tight junctions

Question 23

Types of Epithelial Transport

Answer 23

Paracellular transport
Transcytosis movement
Transcellular transport

Question 24

Paracellular Transport

Answer 24

Epithelial Transport

-movement of molecules b/w cells

Question 25

Transcytosis Movement

Answer 25

Epithelial Transport

-Through cells via vesicles

Question 26

Transcellular Transport

Answer 26

Epithelial Transport

-Movement through cells uses transport proteins

Question 27

Electrical cell-cell communication

Answer 27

Action potentials

Neurotransmitters

Question 28

Chemical cell-cell communication

Answer 28

• Local mediators
• Gap junctions
• Autocrine and paracrine signals diffuse through ECF to nearby cells
• Hormones

Question 29

Range of RMP

Answer 29

-65mV to -85mV

neurons are at -70mV