Smartbook Part 2

Question 1

What are key functions carried out by membrane proteins?

Answer 1

cell surface identity markers
Transport ions across the membrane
Receive external chemical messages
chemical reactions on surface of membrane

Question 2

Set a membrane proteins are attached to the surface of the membrane by special molecules, associate strongly with phospholipids, what describes anchoring molecules

Answer 2

They are modified lipid
They have chemical bonding domains that link them directly to the membrane proteins

Question 3

What are the functions carried out by membrane proteins

Answer 3

Receive external chem messages
Attached membrane to cytoskeleton
Connect adjacent cells and hold them together

Question 4

Transmembrane proteins must span the lipid bilayer at least ______ times to be anchored in the interior of the cell membrane

Answer 4

One

Question 5

Membrane proteins can be anchored to the surface of the membrane by attached to the molecule associate strongly with phospholipids an insert into the lipid bilayer. These molecules are

Answer 5

Modified lipids

Question 6

The hydrophobic region of a transmembrane proteins, which extends through the lipid bilayer contacting the nonpolar interior of the membrane, might be composed of what

Answer 6

B pleated sheets containing nonpolar amino acids
A helices containing nonpolar amino acids

Question 7

Transmembrane domain has

Answer 7

Hydrophobic amino acids

Question 8

Different proteins can cross the membrane in diff ways
What is the primary difference between transmembrane protein in terms of how they cross the membrane

Answer 8

Different proteins can cross the membrane a different number of times

Question 9

Transmembrane B-sheets 1040 through a motif through the membrane that allow molecules pass through the membrane. This type of protein is called a

Answer 9

Pore protein

Question 10

Each membrane-spanning region of a transmembrane protein is called a

Answer 10

Transmembrane domain

Question 11

What is the function of transmembrane proteins called reticulons

Answer 11

They can cause a membrane to bend or even form a tube

Question 12

Transport that occurs without a cell expanding any of its own energy is called

Answer 12

Passive transport

Question 13

Describe pore proteins

Answer 13

They transmembrane proteins
They create openings or channels in the membrane that allow specific ions or molecule to pass through
They have extensive non-polar regions that are folded into a beta pleated sheets

Question 14

when the concentration of a substance on one side of the membrane is different from its concentration on the other side of the membrane the substance is said to exhibit a concentration______

Answer 14

Gradient

Question 15

due to the constant random motion of its atoms and molecules a substance will exhibit net movement from a region where it has higher concentration to a region where it has low concentration and net movement is called

Answer 15

Diffusion

Question 16

which of the following transmembrane proteins are likely to be found in the membranes that form tubular structures

Answer 16

Reticulons

Question 17

diffusion is caused by

Answer 17

Constant random motion of all atoms in molecules

Question 18

When the concentration of a substance varies from one region to another, the substance is exhibit a

Answer 18

Concentration Gradient

Question 19

A major barrier to crossing a biological membrane is it the hydrophobic interior of the membrane that repels what kind of molecules?

Answer 19

Polar molecules

Question 20

what is the permeability of a typical cell membrane to a large polar molecule

Answer 20

Very limited permeability

Question 21

Substance that cannot easily crossed by lipid bilayer, can still diffuse across the plasma membrane with the help of what

Answer 21

Specific channel, proteins or carrier proteins

Question 22

oxygen diffuses across the plasma membrane due to what

Answer 22

All oxygen molecules are in constant random motion

Question 23

In cell membranes the interior of the lipid bilayer repels what

Answer 23

Ions
Polar molecules
Hydrophilic molecules

Question 24

Of the two types of transport proteins that mediate facilitated diffusion, ____ proteins actually bind with the sub being transported, while _____ proteins simply provide a hydrophilic space for the substance to move through

Answer 24

Carrier
Channel

Question 25

transport proteins that actually find a specific substance being transported across the membrane are called

Answer 25

Carrier proteins

Question 26

diffusion that is assisted by Chanel proteins or carrier proteins called

Answer 26

Facilitated diffusion