Quiz 2

Question 1

plasma membrane structure and function

Answer 1

structure: lipid bilayer
function: physical barrier, gateway for exchange, communication, and site of attachment

Question 2

transcellular

Answer 2

transport that goes THROUGH the membrane

Question 3

paracellular

Answer 3

transport that goes PARALLEL to the membrane

Question 4

passive transport

Answer 4

materials move down gradient, no energy is required

Question 5

active transport

Answer 5

materials move against gradient, requires energy (ATP)

Question 6

What are the four types of passive flux?

Answer 6

simple diffusion
osmosis
facilitated diffusion
bulk filtration

Question 7

simple diffusion

Answer 7

passive and random motion of molecules in solution
moving from high to low concentration
rapid over short distances
directly related to temp
indirectly related to molecular size and fluid viscocity

Question 8

osmosis

Answer 8

diffusion of water across a selectively permeable membrane
high solute conc.= low H2O conc.
cells with high solute conc. have high osmotic pressures

Question 9

isotonic solution

Answer 9

conc. of solute outside cell=conc inside the cell

Question 10

hypertonic solution

Answer 10

conc. of solute outside cell>conc. inside the cell
water flows out (cell shrinks)

Question 11

hypotonic solution

Answer 11

conc. of solute outside cell<conc. inside the cell
water flows in (cell swells)

Question 12

aquaporins

Answer 12

membrane-transport proteins providing a facilitated pathway for water flow through the membrane

Question 13

facilitated diffusion

Answer 13

“easier diffusion”
movement from high to low conc. through a protein

Question 14

bulk filtration

Answer 14

concentrated movement of large groups of molecules (often including water)
everything moves in the same direction
often occurs in response to pressure

Question 15

Fick’s law (equation)

Answer 15

Jnet=-Ds(dCs/dx)
- jnet= flu
- Ds= diffusion coefficient
- dCs/dx= concentration gradient of solute

Question 16

Fick’s Law says…

Answer 16

flux is PROPORTIONAL to temp, concentration gradient, area, and membrane permeability
flux is INVERSELY proportional to friction, molecule size, fluid viscosity, and membrane thickness

Question 17

Types of Transporters

Answer 17

ion channel
carriers
pumps

Question 18

Ion channels

Answer 18

membrane proteins that, when open, act as a passive conduit for ions through the membrane
cycle between open and closed conformations

Question 19

Ion channels gated by…

Answer 19

leaky
ligand
mechanical “pull”
voltage
some are sensitive to temp-how we detect hot/cold

Question 20

leaky gated

Answer 20

channel randomly opens/closes

Question 21

ligand gated

Answer 21

chemical stimulus opens the channel

Question 22

mechanically gated

Answer 22

mechanical stimulus opens the channel

Question 23

voltage

Answer 23

change in membrane potential opens the channel

Question 24

Carriers/transporters

Answer 24

transport of solutes across a cell membrane
can facilitate active/passive transport

Question 25

mechanistic theme for carriers

Answer 25

conformational changes

Question 26

alternating access model

Answer 26

carriers cycle between multiple conformations in which a solute binding site is accessible on one side of the membrane or the other never an open channel all the way through membrane

Question 27

occlusion state

Answer 27

state where the solute may not access either the inside or the outside

Question 28

Pumps

Answer 28

movement of molecules against concentration gradient

Question 29

Primary Active transport

Answer 29

directly requires ATP movement of one (or more) solutes AGAINST their gradient using chemical energy (ATP)

Question 30

Secondary Active transport

Answer 30

utilizes energy stored in pre-existing conc. gradients movement of one or more solutes down their conc. gradients provides the energy for the movement of other solutes AGAINST their conc. gradients

Question 31

uniport

Answer 31

movement of 1 thing in 1 direction

Question 32

symport

Answer 32

movement of 2+ things in the same direction

Question 33

antiport

Answer 33

movement of 2+ things in different directions

Question 34

Epithelial tissue

Answer 34

appears on surfaces involved in exchange, transport, movement/clearing, protection, secretion, and sensation

Question 35

two types of secretion

Answer 35

duct (exocrine)- outside body ductless (endocrine)- inside body

Question 36

merocrine

Answer 36

secretory products secreted by vesicular exocytosis most common form, often continuous ex. sweat and saliva

Question 37

apocrine

Answer 37

partial cellular breakdown (fragmentation) cytoplasm and vesicular contents secreted ex. milk and underarm sweat

Question 38

holocrine

Answer 38

entire cell lost with secretion stem cells divide to replace lost cells ex. oil glads

Question 39

types of intercellular junctions

Answer 39

tight junctions adhering junctions desmosomes gap junctions

Question 40

tight junctions

Answer 40

"gatekeeper" prevent substances from moving between cells encircle cells near apical surface

Question 41

adhering junctions

Answer 41

actin-filament based systems encircle cells immediately adjacent to all its neighbors located deep to the tight junctions

Question 42

desmosomes

Answer 42

tie cells together allow bending and twisting do not encircle cell provide resistance to stress

Question 43

gap junctions

Answer 43

protein channels that allow rapid communication between cells

Question 44

Connective tissue forms

Answer 44

connective tissue proper (loose and dense) supporting connective tissue fluid connective tissue

Question 45

connective tissue consists of...

Answer 45

specialized cells protein fibers ground substance

Question 46

extracellular matrix is made up of...

Answer 46

protein fibers ground substance

Question 47

muscle tissue function

Answer 47

contract (shorten) when stimulated to create movement

Question 48

three types of muscle tissue

Answer 48

skeletal- multinucleated + striated cardiac- striations + intercalated discs smooth- no striations

Question 49

nervous tissue function

Answer 49

communication and control of the body

Question 50

two types of nervous tissue

Answer 50

neuron- nerve cells capable of initiating/conducting electrical activity neuroglia (glia)- cells that support neurons