E2 Chapter 7: Membrane Structure and Function

Question 1

The two staple ingredients in making a cell membrane are

Answer 1

1. Proteins
2. Lipids

Question 2

Basic unit of life

Answer 2

Cells

Question 3

What forms the boundary between interior region and outside region of the cell?

Answer 3

Plasma membrane

Question 4

The interior region contains __________, which is made up of ____________

Answer 4

Cytoplasm; cytosol

Question 5

The phospholipid head is ____________ and _______ water

Answer 5

Hydrophilic; and loves water (polar)

Question 6

The fatty acid tails are __________ and ___________ water

Answer 6

Hydrophobic; hate water (nonpolar)

Question 7

Just like the phospholipid bilayer, membrane proteins are _______________, meaning they contain both hydrophobic and hydrophilic parts

Answer 7

amphipathic

Question 8

The plasma membrane is slightly permeable. This is due to what reasons? (2)

Answer 8

1. Hydrophilic and hydrophobic DO NOT interact
2. The interior of plasma membrane is nonpolar/hydrophobic

Question 9

What is the currently accepted cell model called?

Answer 9

Fluid mosaic model

Question 10

A membrane is held together by ______________, which is weaker than what type of bonding?

Answer 10

hydrophobic interactions; covalent bonding

Question 11

The membrane exhibits ________________ ___________, which is allowing certain things to cross compared to others

Answer 11

Selective permeability

Question 12

What are easy to diffuse across the membrane?

Answer 12

Small nonpolar/hydrophobic molecules

Question 13

What is the diffusion of small nonpolar molecules called?

Answer 13

Simple diffusion

Question 14

Why do certain molecules simple diffuse? (2)

Answer 14

1. Can interact with a hydrophobic interior
2. Can squeeze past the membrane easily

Question 15

What molecules do not diffuse easily?

Answer 15

Hydrophilic/polar molecules
Large molecules

Question 16

Why do certain molecules not pass through the membrane easily?

Answer 16

1. Polar does not readily interact with hydrophobic interior
2. Too big to squeeze through

Question 17

What do polar/large molecules use to enter a cell?

Answer 17

Active transport

Question 18

What type of proteins enable passage of molecules that cannot pass?

Answer 18

Transport proteins

Question 19

Where are transport proteins?

Answer 19

Embedded in lipid bilayer

Question 20

What proteins form a hydrophilic open corridor that only certain polar ions can use to get into the membrane?

Answer 20

Channel proteins

Question 21

Any molecules simply diffusing are moving against/with the concentration gradient?

Answer 21

With; moves DOWN the conc grad

Question 22

The diffusion of free water across a selectively permeable membrane

Answer 22

Osmosis

Question 23

When surrounding a certain cell, will cause the cell to lose water

Answer 23

Hypertonic surroundings

Question 24

When surrounding a certain cell, will cause the cell to gain water

Answer 24

Hypotonic surroundings

Question 25

The passage of molecules/ions down their electrochemical gradient with the assistance of specific transmembrane ptein

Answer 25

Facilitated diffusion

Question 26

Na+ VG channels are examples of what type of protein?

Answer 26

Channel proteins

Question 27

Pumping a solute across a membrane against its gradient takes a lot of energy in a process called

Answer 27

Active Transport

Question 28

A pump that transports sodium out and potassium into the cell AGAINST their gradients

Answer 28

Sodium potassium pump

Question 29

Na+/k+ pump pumps __ K into or out of?

Answer 29

2 K into

Question 30

Na+/K+ pumps __ Na into or out of?

Answer 30

3 Na out of

Question 31

Is the inside of the cell more positive or negative?

Answer 31

Negative

Question 32

The voltage across a whole membrane is called

Answer 32

Membrane potential

Question 33

The diffusion of free water across a selectively permeable membrane, _______________, which actively transports protons (hydrogen ions, ) out of the cell

Answer 33

Proton pump (H+)