Chapter 7 - Cell Membrane

Question 1

Cell Membrane

Answer 1

boundary between inside and outside of Cell

Question 2

Phospholipid Bilayer

Answer 2

double layer of a molecule made of a phosphate group, glycerol, and 2 lipids

Question 3

Amphipathic

Answer 3

A molecule with hydrophilic and hydrophobic ends

Question 4

Which part of the phospholipid is hydrophobic and which is hydrophilic?

Answer 4

Lipid - hydrophobic (repells water)

Phosphate - Hydrophilic (attracted to water)

Question 5

What method did we use to study and learn more about the cell membrane with?

Answer 5

Freeze-Fracture method

Question 6

Fluid Mosaic Model

Answer 6

The Cell membrane is flexible and fluid while also being made up of many different parts

Question 7

How does temperature impact the fluidity of the cell membrane?

Answer 7

Colder temps make the membrane more ridged

Question 8

What is the role of cholesterol in the cell membrane?

Answer 8

Cholesterol functions as a buffer to the changes caused by temperature variation

Question 9

What two general categories of proteins form on or through the cell membrane?

Answer 9

Integral Proteins - Through the membrane

Peripheral Proteins - attached to, but not full width of membrane

Question 10

What are the 6 functions of cell membrane proteins we discussed in class?

Answer 10

1. Transport
2. Enzymatic Activity
3. Signal Transfer (transduction)
4. Cell-cell recognition
5. Intercellular joining
6. Attachment to cytoskeleton

Question 11

Glycolipids and Glycoproteins

Answer 11

Lipid or protein with a carbohydrate chain attached; Used for cell to cell recognition

Question 12

Selective Permeability

Answer 12

Allows for some substances to pass through while others are not allowed

Question 13

Passive Transport

Answer 13

Movement of substances across the Cell membrane without energy

Question 14

Diffusion

Answer 14

Movement of substances across the cell membrane from higher to lower concentrations (example CO2 and O2)

Question 15

Facilitated Diffusion

Answer 15

Movement of substance across the cell membrane from higher to lower concentrations via a transport protein

Question 16

Channel protein

Answer 16

tunnel though the cell membrane to assist in transport

Question 17

Aquaporins

Answer 17

Channel proteins specifically to move water in and out of the cell

Question 18

Carrier Protein

Answer 18

Transport protein that changes shape to allow substances to move across the membrane

Question 19

Osmosis

Answer 19

Facilitated Diffusion of water molecules

Question 20

Isotonic Solution

Answer 20

Solution with the same concentration of solutes as the cell (equilibrium)

Question 21

Hypertonic Solution

Answer 21

Solution with a higher concentration of solutes than the cell (water leaves the cell)

Question 22

Hypotonic Solution

Answer 22

Solution with a lower concentration of solutes than the cell (Water enters the cell)

Question 23

Active Transport

Answer 23

movement of substance across the cell membrane from low to high concentrations, via carrier proteins, and with the help of ATP

Question 24

Sodium-Potassium Pump

Answer 24

3 Sodium (Na) out of cell, 2 Potassium (K) into cell

Active Transport that creates a electric differential across cell membrane

Question 25

Electrogenic Pump

Answer 25

Active transport that generates a voltage across the cell membrane (ie. NA-K pump and Proton pump)

Question 26

Cotransport

Answer 26

An active transport run in part or whole by a separate active transport

Question 27

Exocytosis

Answer 27

Releasing of substances out of cell by a vesicle fusing with the cell membrane then opening up

Question 28

Endocytosis

Answer 28

Cell taking in substances by engulfing them

Question 29

Phagocytosis

Answer 29

“eating” of large particles by being engulfed (white blood cells “eating” foreign substances in body.

Question 30

Pinocytosis

Answer 30

“Drinking” from outside of cell by engulfing a liquid

Question 31

Receptor-Mediated Endocytosis

Answer 31

Bulk consumption of specific substances that have bound to receptors; limiting the undesired substances