Movements Through Cell Membrane

Question 1

passive transport

Answer 1

-Physical process that requires no cellular energy

Question 2

4 examples of passive transport

Answer 2

• Simple diffusion
• facilitated diffusion
• osmosis
• filtration

Question 3

Active transport

Answer 3

Physiological process that requires energy

Question 4

3 examples of active transport

Answer 4

• endocytosis
• exocytosis
• transcytosis

Question 5

Simple diffusion

Answer 5

Movement of substances from regions of higher concentration to regions of lower concentration (no energy required)

Question 6

In what 3 substances does simple diffusion occur?

Answer 6

Oxygen, carbon dioxide, and lipid-soluble substances

Question 7

What is another way to explain going from high concentration to low concentration?

Answer 7

Going down/along the concentration gradient

Question 8

Facilitated Diffusion

Answer 8

Diffusion across a membrane with help of a channel or carrier molecule (no energy required)

Question 9

Phenomenon

Answer 9

Event you observe; either good/bad

Question 10

Saline

Answer 10

salt

Question 11

Osmosis

Answer 11

Simple diffusion; movement of water through a selectively permeable membrane from regions of higher concentration to regions of lower concentration.

Question 12

In what direction does water move during osmosis?

Answer 12

Toward a higher concentration of solutes; (high concentration of WATER to low concentration of WATER)

Question 13

Osmotic Pressure

Answer 13

Ability of osmosis to generate enough pressure to move a volume of water

Question 14

Osmotic pressure _____________ as the concentration of non permeable solutes increases

Answer 14

Osmotic pressure INCREASES

Question 15

Isotonic

Answer 15

Same osmotic pressure

RBC: normal physiological saline (0.85% NaCl)

Question 16

Hypertonic

Answer 16

Higher osmotic pressure

RBC: crenation (i.e., 1.5% NaCl)

Question 17

Hypotonic

Answer 17

Lower osmotic pressure

RBC: hemolysis (i.e., 0.25% NaCl)

Question 18

Filtration

Answer 18

Smaller molecules are forced through porous membranes.

Hydrostatic pressure is important in the body

Question 19

Hydrostatic pressure

Answer 19

Pressure a fluid exerts on the wall of its container

Question 20

Filtrate

Answer 20

Substances you collect after filter

Question 21

Active transport

Answer 21

*Requires energy (ATP)

Carrier molecules transport substances across a membrane from regions of lower concentration to regions of higher concentration

(against concentration gradient)

Question 22

What molecules are usually involved in active transport? (4)

Answer 22

Sugars, amino acids, sodium ions, potassium ions

Molecules the cell really needs

Question 23

Endocytosis

Answer 23

Cell engulfs a substance by forming a vesicle around the substance

Question 24

Receptor-mediated endocytosis

Answer 24

requires the substance to bind to a membrane-bound receptor

Question 25

What are two factors that affect the rate of diffusion?

Answer 25

1. Temperature (warmer=happen faster)

2. Size

Question 26

Exocytosis

Answer 26

Reverse of endocytosis
Substances in a vesicle fuse with cell membrane; contents released outside of the cell

i.e., release of neurotransmitters from nerve cells

Question 27

Transcytosis

Answer 27

Endocytosis followed by exocytosis; transports a substance rapidly through a cell

i.e., HIV crossing a cell layer