Exam 2 - Chapter 7

Question 1

cell vs plasma membrane

Answer 1

cell membrane is any membrane of the cell.

plasma membrane is the outermost membrane of the cell

Question 2

Fluid Mosaic Model

Answer 2

• The “fluid” part refers to the fluidity of the membrane

* The “mosaic” part refers to the various components that make up the membrane

Question 3

Peripheral proteins

Answer 3

associated with one side of the membrane

Question 4

Integral proteins

Answer 4

embedded within the membrane

Question 5

Transmembrane proteins

Answer 5

integral proteins that fully span the membrane

Question 6

Transport proteins

Answer 6

move specific solutes into or out of the cell

Question 7

Enzymes

Answer 7

catalyze a chemical reaction

Question 8

Signal transduction

Answer 8

relay cellular messages

Question 9

Cell-cell recognition

Answer 9

attach two adjacent cells together, recognize “self cells”

Question 10

Intercellular joining

Answer 10

connection between adjacent cells

Question 11

Attachment

Answer 11

to cytoskeleton and extracellular matrix, maintains cellshape and stabilizes the location of membrane proteins

Question 12

Extracellular Matrix

Answer 12

• composed of proteins, other macromolecules, and fluids secreted by the cells
• Functions to stabilizes the structure of tissues and protects and supports the plasma membrane

Question 13

Selective Permeability

Answer 13

• Some molecules can pass the plasma membrane freely if they are small,uncharged, non-polar, and/or hydrophobic
• Gases like O2 and CO2
• Hydrophobic lipids
• Water (less freely)
• But ions, most polar molecules, and large molecules cannot

Question 14

Passive Transport

Answer 14

• fueled by kinetic energy
• molecules move down their concentration gradient
• concentration gradient serves as a form of potential energy

Question 15

Diffusion

Answer 15

spontaneous spreading of molecules down their concentration gradient from an area of higher concentration to an area of lower concentration, fueled by kinetic energy

Question 16

Diffusion Factors

Answer 16

• Mass – heavier molecules tend to diffuse more slowly, lighter molecules tend to diffuse more quickly •Temperature – higher temperatures increase diffusion rate, lower temperatures decrease diffusion rate
• Extent of the concentration gradient – the greater the difference in concentration the greater the diffusion rate, the smaller the difference in concentration the slower the diffusion rate
• Density of solvent, solubility of solute, distance molecules must travel

Question 17

Osmosis

Answer 17

diffusion of water across a selectively permeable membrane, water moves down its concentration gradient from an area of higher free water to an area of lower free water, fueled by kinetic energy

Question 18

Osmosis Factors

Answer 18

•Osmosis occurs when there is a concentration gradient of water across a semipermeable membrane •Water moves down its concentration gradient equalizing water and solute concentrations on either side of the membrane

Question 19

Tonicity

Answer 19

the ability of an extracellular solution to cause a cell to gain orlose wate

Question 20

Osmolarity

Answer 20

a solutions total solute concentration

Question 21

Isotonic

Answer 21

equal solute concentrations in ECF and ICF, no net movement of water

Question 22

Hypotonic

Answer 22

solute concentration of ECF is lower than solute concentration of ICF, water moves into cell

Question 23

Hypertonic

Answer 23

solute concentration of ECF is higher than solute concentration of ICF, watermoves out of cell

Question 24

Facilitated diffusion

Answer 24

solute binds to transport protein and moves across membrane down its concentration gradient from an area of higher concentration to an area of lower concentration, fueled by kinetic energy

Question 25

Channel proteins

Answer 25

always open or gated, like a “door” that opens only to specific molecules

Question 26

Carrier proteins

Answer 26

pick up specific moleculeson one side of the membrane and releases it onto the other side of the membrane

Question 27

Aquaporins

Answer 27

water based channels that allow access across the membrane

Question 28

Active transport

Answer 28

Diffusion (small molecules), osmosis (water), facilitated diffusion (ions, polar molecules, smaller biomolecules) movement of molecules against their concentration gradient from an area of lower concentration to an area of higher concentration, fueled by ATP

Question 29

Protein Mediated Active Transport

Answer 29

transport protein (carrier protein) pumps a solute against its concentration gradient, from an area of lower concentration to an area of higher concentration, fueled by ATP

Question 30

Vesicle Transport

Answer 30

use of a vesicle to transport large particles or bulk substances into or out of the cell without actually passing through the membrane, requires ATP

Question 31

Exocytosis

Answer 31

use of a vesicle to move materials out of the cell

Question 32

Endocytosis

Answer 32

use of a vesicle to move materials into the cell

Question 33

Phagocytosis

Answer 33

movement of solids

Question 34

Pinocytosis

Answer 34

movement of fluids

Question 35

Receptor mediated endocytosis

Answer 35

targeted endocytosis

Question 36

Passive transport

Answer 36

Protein mediated active transport, vesicle transport