Movement In + Out of Cells

Question 1

solute

Answer 1

a substance that can be dissolved

Question 2

solvent

Answer 2

a substance that does the dissolving

Question 3

solution

Answer 3

when the solute has dissolved and is no longer distinguishable from the solvent (a uniform mixture)

Question 4

intracellular

Answer 4

w/in a cell

Question 5

extracellular

Answer 5

outside of a cell

Question 6

intercellular

Answer 6

between cells (interstitial)

Question 7

What are types of PASSIVE processes?

Answer 7

diffusion, facilitated diffusion, osmosis, filtration

Question 8

What is a passive process?

Answer 8

a process that doesn’t require energy needed by the cell

Question 9

What is diffusion?

Answer 9

• is the mvmt of molecules (ions + water) from HIGH to LOW concentration
• oxygen enters the cell
• carbon dioxide leaves the cell
• occurs by simple diffusion through the lipid layer of the cell membrane

Question 10

What is facilitated diffusion?

Answer 10

• diffusion w/ the aid from carrier proteins
• glucose enters the cell

Question 11

What is osmosis?

Answer 11

• mvmt of water through a semipermeable membrane from LOW to HIGH solute concentration (high solvent to low solvent)
• water constantly moves in and out of the cell

Question 12

What is osmotic pressure?

Answer 12

amt of pressure necessary to stop the flow of water across the membrane

Question 13

What is filtration?

Answer 13

• substances are forced through a membrane by hydrostatic pressure, small solutes pass through, larger molecules don’t
• important in kidney function*

Question 14

What are active processes?

Answer 14

processes that need energy from the cell

Question 15

Examples of active processes

Answer 15

endocytosis, exocytosis, active transport

Question 16

Endocytosis

Answer 16

materials taken into the cell

Question 17

What are examples of endocytosis?

Answer 17

phagocytosis, pinocytosis, receptor-mediated

Question 18

Phagocytosis

Answer 18

• “cell eating”
• cell membrane extends around solid particles
• some WBCs and macrophages are phagocytic

Question 19

Pinocytosis

Answer 19

• bulk phase
• “cell drinking”
• cell membrane extends around fluid droplets
• important in absorptive cells in the small intestine

Question 20

Receptor-mediated

Answer 20

• specialized membrane receptors bind to substances entering the cell
• enzymes, insulin, hormones, iron + cholesterol enter the cell this way

Question 21

Exocytosis

Answer 21

• materials exit the cell
• waste products are excreted
• useful products are secreted into the extracellular space
• hormones, neurotransmitters, and mucus are released from the cell this way

Question 22

Active transport

Answer 22

• mvmt of molecules from LOW to HIGH concentration w/ the aid of carrier proteins

Question 23

What is an example of active transport?

Answer 23

• sodium-potassium pump (a pump w/in cells)
• most ions + AAs move INTO cells this way

Question 24

Hypotonic

Answer 24

• extracellular fluid is LESS concentrated than intracellular fluid
• RBCs placed in a hypotonic solution gains water through osmosis which results in the cell bursting (hemolysis)

Question 25

Hypertonic

Answer 25

• extracellular fluid is MORE concentrated than intracellular fluid
• RBCs placed in a hypertonic solution LOSES water through osmosis which results in cremate (shrivel)

Question 26

Isotonic

Answer 26

• concentrations are equal
• RBCs remain unchanged in isotonic solution because osmotic pressures are equal