1.4

Question 1

***imported by membrane transport

Answer 1

glucose, hormones, ions

Question 2

exported by membrane transport

Answer 2

enzymes, hormones, waste products toxic to cell and substances in need of secretion

Question 3

types of passive transport

Answer 3

simple diffusion, faciliated diffusion, osmosis

Question 4

diffusion

Answer 4

the movement of particles down a concentration gradient, as a result of random motion of particles, though a partially permeable membrane

Question 5

***diffusion is affected by factors:

Answer 5

1. temperature
2. SA of membrane
3. size of particles
4. concentration gradient of diffusing particles

Question 6

simple diffusion

Answer 6

occurs in a gas or liquid medium, only requires a concentration gradient, random movement of molecules, goes from high to low concentration; if a molecule is too big or charged, it cannot pass though the phospholipid bilayer by simple diffusion and needs faciliated diffusion

Question 7

facilitated diffusion

Answer 7

requires channel or carrier proteins, across the plasma membrane, from high to low concentration; size and shape of those proteins determine what substances can cross the membrane

Question 8

***voltage gated

Answer 8

proteins open and close with change in electrical potential to control movement of potassium ions

Question 9

osmosis

Answer 9

the passive movement of water molecules from a region of low solute concentration to a region of a high solute concentration across a partially permeable membrane; water moves from hypotonic to hypertonic solution

Question 10

solutes

Answer 10

particles that are dissolved in water (don’t move during osmosis)

Question 11

solvent

Answer 11

water

Question 12

***osmolarity

Answer 12

a measure of the solute concentration; concentration of a solution in terms of mol/dm^3 of solution

Question 13

hypertonic solution

Answer 13

higher concentration of solutes

Question 14

hypotonic solution

Answer 14

lower concentration of solutes

Question 15

isotonic solution

Answer 15

concentration of solutes is equal between the two solutions

Question 16

if in hypotonic solution

Answer 16

cell swells up, because of osmotic uptake of water

Question 17

if in isotonic solution

Answer 17

no net movement of water

Question 18

if in hypertonic solution

Answer 18

cell shrinks because of osmotic loos of water

Question 19

active transport

Answer 19

the movement of particles across membranes against concentration gradient, from a region of low concentration to one of a higher concentration, requiring energy in the form of ATP; carried out by globular proteins (pump)

Question 20

where is active transport being used

Answer 20

roots of plants, epithelial cells of the small intestine (glucose)

Question 21

axon

Answer 21

part of a neuron that conveys messages rapidly from one body part to another in nerve impulse; it has high K ions concentrations on the inside and high Na ions concentration on the outside

Question 22

nerve impulse

Answer 22

rapid movements of sodium and then potassium ions across axon membrane

Question 23

***steps of active transport of Na and K in axons

Answer 23

1. when the pump is open to the inside of axon, 3 Na ions enter the pump and attach to their binding sites
2. ATP donates a phosphate group to the pump
3. the previous stage causes the protein to change shape expelling Na ions to the outside
4. 2 K ions from the outside enter and attach to their binding sites
5. the binding of K ions leads to the release of the phosphate group which causes pump to change shape again so that it is only open to the inside of the axon
6. K ions are released inside
7. Na ions can now enter and bind to the pump again

Question 24

***how are K channels built

Answer 24

4 protein subunits with a narrow pore between them that allows K ions to pass in either direction, net negative charge inside the axon and net positive charge outside

Question 25

***facilitated diffusion in potassium axons

Answer 25

1. K dissolves, becomes bonded to a shell of H2O molecules and becomes too large to pass through the pore 2. bonds between K+ and H20 Are broken and bonds form temporarily between K+ and a series of amino acids in the narrowest part of the pore 3. after K+ passed though this part of pore, it can become associated with H2O again -at stage during nerve impulse - more positive charges are inside and that's when channels open!!!

Question 26

endocytosis

Answer 26

active transport allowing particles to enter the cell, amoeba nd paramecium use it for food uptake

Question 27

phagocytosis

Answer 27

uptake of pathogens by endocytosis, using phagocytic vacuole and lysosomes for digestion

Question 28

pinocytosis

Answer 28

uptake of fluids by endocytosis

Question 29

to form a vesicle

Answer 29

a small region of membrane is pinched off (carried out by proteins using ATP)

Question 30

exocytosis

Answer 30

release of particles by active transport

Question 31

excretion

Answer 31

any undigested remains of the microbe that are not useful to the cell are excreted outside the cell

Question 32

***secretion

Answer 32

proteins synthesized by ribosomes on rER are first passed to Golgi apparatus via vesicles, where they are processed and packaged being released in vesicles that in turn fuse with the plasma membrane for secretion outside the cell

Question 33

role of vesicle for the growth of a cell

Answer 33

area of plasma membrane needs to increase - vesicles carrying proteins from rER fuse with membrane, each time increasing it by small amount

Question 34

estimation in osmolarity in tissues formula

Answer 34

( (final mass - initial mass) / initial mass ) x 100

Question 35

***dependent variable

Answer 35

percent change in mass (mass taken before and after it's been bathed in solutions)

Question 36

***independent variable

Answer 36

concentration of NaCl - minimum 5 different concentrations

Question 37

***control variables

Answer 37

number of trials, size of the plant tissue, time in solution, age of the plant tissue, same temperature

Question 38

***protein channels

Answer 38

have hydrophilic pores that allow passage of ions

Question 39

***carrier proteins

Answer 39

conformational change enables translocation

Question 40

hydrolysis

Answer 40

releases one P group and a lot of energy