Ch7

Question 1

Surrounds the cell & separates the inside from the outside of the cell

Answer 1

plasma membrane

• regulates what enters and leaves the cells
• semi-permeable

Question 2

Which parts of the Phospholipid bilayer is hydrophilic & hydrophobic?

Answer 2

phosphate head groups, fatty acid tails

Question 3

Where are proteins embedded in?

Answer 3

the phospholipid bilayer

Question 4

Define integral proteins

Answer 4

proteins spanning the plasma membrane that penetrate the bilayer from one side to the other
*function as receptors, channel proteins, carrier proteins and enzymes

Question 5

Define peripheral proteins

Answer 5

proteins associated with the surface of the plasma membranes that only partially penetrate the bilayer
*function as attachment sites for the cell cytoskeleton and extracellular proteins

Question 6

Define glycoproteins

Answer 6

proteins that face the outside of the cell have sugars attached to them, involved in cell to cell recognition

Question 7

Define glycolipids

Answer 7

phospholipids with sugars attached to phosphate head

Question 8

Define Passive Transport Mechanism

Answer 8

transport across the plasma membrane that requires no energy

Question 9

Define Diffusion

Answer 9

movement of molecules from highly concentrated areas to areas less concentrated

Question 10

What diffuses the easiest through plasma membranes?

Answer 10

gasses such as oxygen, carbon dioxide, nitrous oxide, and carbon monoxide

Question 11

What diffuses readily through the plasma membrane?

Answer 11

lipid soluble molecules such as steroid hormones, cholesterol etc

Question 12

Define Osmosis

Answer 12

diffusion of free water molecules through a plasma membrane (semi permeable) with the help of water channel proteins called Aquaporins

Question 13

What need water molecules bound to them to keep them in solution?

Answer 13

solutes

Question 14

The number of solutes in and out of cells which controls the diffusion of free water molecules across the plasma membrane

Answer 14

tonicity

Question 15

Free water molecules always diffuse from what to what?

Answer 15

a hypotonic environment to a hypertonic environment

Question 16

Animal cells need what solutions? What happens when it is placed in other solutions?

Answer 16

• isotonic solutions
• hypo: lysis/cell pop
• hyper: crenate/shrivel

Question 17

Plant cells need what solutions? What happens when it is placed in other solutions?

Answer 17

• hypotonic solutions, makes them turgid
• iso: flaccid/start to wilt
• hyper: plasmolysis/shrivel inside their cell walls

Question 18

What does Facilitated Diffusion do?

Answer 18

Channel proteins for certain ions & Carrier proteins for certain molecules: molecule outside cell binds to carrier protein in plasma membrane, which causes it to change its conformation (shape) & this releases the molecule inside the cell
*another form of passive transport in which energy is not used

Question 19

Define Active Transport

Answer 19

transport across the plasma membrane that requires energy, needs P in ATP to move molecule from an area of low concentration to an area of high concentration

Question 20

Define Phagocytosis

Answer 20

cell eating

*cells can pull in bacteria, viruses, food particles into vesicles

Question 21

Define Pinocytosis

Answer 21

cell drinking

*cells can pull in extracellular fluid in vesicles

Question 22

Define Receptor-mediated endocytosis

Answer 22

when a molecule binds to a receptor on the cell surface and is internalized via a coated vesicle

Question 23

What molecules make up the plasma membrane in animals?

Answer 23

phospholipids, proteins, glycoproteins, & glycolipids

Question 24

What makes up the cell wall of plants? Bacteria?

Answer 24

• cellulose

- peptidoglycan

Question 25

Define Exocytosis

Answer 25

when a vesicle fuses with the plasma membrane and its contents exits the cell as in secreted proteins