Week 4

Question 1

Plasma membrane

Answer 1

Border of the cell.

Question 2

What does the plasma membrane look like?

Answer 2

It appears as pair of dark parallel lines when viewed with an electron microscope.

Question 3

Does a plasma membrane have both intracellular and extracellular faces? True or false

Answer 3

True

Question 4

What are the three functions of the plasma membrane?

Answer 4

Defines cell boundaires
Governs interactions with other cells
Controls passage of materials in and out of the cell

Question 5

98% of membrane molecules are?

Answer 5

Lipids

Question 6

The heads of phospholipids are?

Answer 6

Hydrophilic ( water-loving) Polar

Question 7

The tails of phospholipids are?

Answer 7

Hydrophobic (water-fearing) nonpolar

Question 8

Cholesterol

Answer 8

20% of the membrane lipids.
It holds phospholipids still and can stiffen the membrane.

Question 9

Glycolipids

Answer 9

5% of the membrane lipids
Phospholipids with short carbohydrate chains on the extracellular face.
Contributes to glycocalyx- carbohydrate coating on the cell surface.

Question 10

Membrane proteins

Answer 10

Are common protein molecules that are attached to, or associated with the membrane of a cell or an organelle.

Question 11

Integral proteins

Answer 11

Is a protein that is permanently attached to the biological membrane.

Question 12

Peripheral proteins

Answer 12

Adhere to one face of the membrane and usually tether to the cytoskeleton

Question 13

Cilial

Answer 13

A short microscopic hair vibrating structure is found in large numbers on the surface of certain cells. 7-10um long
For example an eyelash

Question 14

Multiple nonmotile cilia location

Answer 14

Found on sensory cells of the nose

Question 15

Ciliopathies

Answer 15

Defects in structure and function of cilia

Question 16

Motile cilia are found where?

Answer 16

Respiratory tract, uterine tubes, ventricles if the brain, ducts to testes.

Question 17

How many Motile cilia are found on each cell

Answer 17

50-200

Question 18

Axoneme

Answer 18

The core of motile cilium

Question 19

How many structures of microtubules does the axoneme have?

Answer 19

9+2

Question 20

Cilia beat freely within a saline layer located where?

Answer 20

The cells surface

Question 21

Chloride pumps pump Cl- into what?

Answer 21

ECF

Question 22

What follows after ECF

Answer 22

Na+ and H2O

Question 23

Where does mucus float?

Answer 23

On top of the saline layer

Question 24

What is the only functional flagellum in humans?

Answer 24

The tail of a sperm cell.

Question 25

Pseudopods

Answer 25

Continually changing extensions of the cell that vary in shape and size.

Question 26

Pseudopods can be used for what?

Answer 26

For cellular locomotion and capturing foreign particles.

Question 27

Plasma membrane and organelle membranes are selectively permeable what does that mean?

Answer 27

They allow some things through but prevent others from passing.

Question 28

Do passive mechanisms require ATP

Answer 28

No.

Question 29

Passive Mechanisms

Answer 29

The random molecular motion of particles provides the necessary energy. filtration, diffusion, osmosis

Question 30

Active mechanisms

Answer 30

Consumes ATP. And is used for two different types of transport Active and Vesicular

Question 31

Carrier

Answer 31

Mediated mechanisms used a membrane protein to transport substances across the membrane

Question 32

Filtration

Answer 32

Particles are driven through the membrane by physical pressure

Question 33

Simple diffusion

Answer 33

The net movement of particles from a place of high concentration to a place of lower concentration

Question 34

Substances diffuse down their concentration gradient do not require a membrane. True or false?

Answer 34

True

Question 35

What are the factors that affect the diffusion rate through a membrane? for simple diffusion.

Answer 35

Temperature Molecular weight The steepness of the concentrated gradient Membrane surface area Membrane permeability pH

Question 36

Osmosis

Answer 36

The net flow of water through a selectively permeable membrane. Moves from higher to lower

Question 37

Some examples of osmotic imbalance.

Answer 37

Diarrhea, constipation, edema

Question 38

Channel proteins in membrane specialized for water passage?

Answer 38

Aquaporins

Question 39

Water can be diffused through the phospholipid bilayer, but osmosis is enhanced by what?

Answer 39

Aquaporins

Question 40

Osmotic pressure

Answer 40

Hydrostatic pressure is required to stop osmosis. Increases the number of nonpermeating solutes

Question 41

Reverse osmosis

Answer 41

The process of applying mechanical pressure to override osmotic pressure allows for water purification

Question 42

Osmolarity

Answer 42

Number if osmoles per liter of solution

Question 43

Tonicity

Answer 43

The ability of a surrounding solution (bath) to affect fluid volume and pressure in a cell.

Question 44

Hypotonic solutions

Answer 44

Causes cells to absorb water and swell. if the cells stay in this solution too long it will cause them to explode and die

Question 45

Has a lower concentration of nonpermeating solutes than intercellular fluid (ICF)

Answer 45

Hypotonic solutions

Question 46

Hypertonic solutions

Answer 46

Causes the cell to lose water and shrivel (crenate)

Question 47

Has a higher concentration of nonpermeating solutes than ICF

Answer 47

Hypertonic solutions

Question 48

Isotonic solutions

Answer 48

Cause no change in the cell volume

Question 49

The concentrations of nonpermeating solutes in the bath and ICF are the same.

Answer 49

Isotonic solution