Unit III

Question 1

What are the functions of cell membrane

Answer 1

Controls what enters and exits the cell to maintain an internal balance

Provides protection and support for the cell

Question 2

The internal balance inside the cell that cell membrane maintains is called

Answer 2

Homeostasis

Question 3

Some membrane contains proteins called

Answer 3

Membrane proteins

Question 4

The phosphate head of the cell membrane is ________, and the fatty acid tails is __________.

Answer 4

Polar, non-polar

Question 5

Allows a molecules in and keeps other molecules out

Answer 5

Selectively permeable

Question 6

In 1972 they proposed that the membrane is a mosaic of proteins dispersed within the bilayer with only the hydrophilic regions exposed to water.

Answer 6

S.J Singer and G. Nicolson

Question 7

70% of cell membrane proteins part and parcel of membrane structure

Answer 7

Integral proteins

Question 8

Lei transfer substances against concentration/ electrical gradient

Answer 8

Pumps

Question 9

Opened and closed by gates

Answer 9

Channel proteins

Question 10

It involved in transport of substances

Answer 10

Carrier proteins

Question 11

It takes place in membrane reaction

Answer 11

Enzyme proteins

Question 12

They bear appropriate sites for recognition of specific ligands

Answer 12

Receptor proteins

Question 13

They are bound to the surface of the membrane

Answer 13

Peripheral proteins

Question 14

Other functions of cell membrane

Answer 14

Transport
Enzymatic activity
Signal transduction
Cell to cell recognition
Intercellular joining
Attachment to the cytoskeleton and extracellular matrix (ECM)

Question 15

Carbohydrates covalently bonded to lipids

Answer 15

Glycolipids

Question 16

Membrane carbohydrates covalently bonded to proteins

Answer 16

Glycoproteins

Question 17

__________ molecules such as hydrocarbons can dissolve in the lipid bilayer and passed through the membrane rapidly

Answer 17

Hydrophobic or nonpolar molecules

Question 18

__________ molecule such as sugars do not cross the membrane easily

Answer 18

Polar molecules

Question 19

It allows passage of hydrophilic substances across the membrane

Answer 19

Transport proteins

Question 20

Transport proteins that have hydrophilic channel that certain molecules or ions can use as a tunnel

Answer 20

Channel protein

Question 21

Channel proteins that facilitate the passage of water

Answer 21

Aquaporins

Question 22

Transport proteins that bind to molecules and change shape to shuttle them across the membrane

Answer 22

Carrier proteins

Question 23

Two types of transport mechanism

Answer 23

Active transport
Passive transport

Question 24

What are the two types of active transport

Answer 24

Primary transport
Secondary transport

Question 25

What are the four types of passive transport

Answer 25

Simple diffusion Facilitated diffusion Osmosis Bulk flow filtration

Question 26

The tendency for molecules spread out evenly into the available space

Answer 26

Diffusion

Question 27

The region along which the density of a chemical substance increase or decrease

Answer 27

Concentration gradient

Question 28

The diffusion of a substance across a biological membrane that uses no energy to make it happened

Answer 28

Passive transport

Question 29

What are the factors that influence diffusion rates

Answer 29

Distance Molecular size Temperature Steepness of concentration gradient Membrane of surface area

Question 30

Two types of diffusion across membranes

Answer 30

Simple diffusion Channel mediated diffusion

Question 31

Lipophilic substances can enter cells easily because they diffuse through the lipid portion of the membrane

Answer 31

Simple diffusion

Question 32

It is used by irons very small water-soluble compounds. Much more complex than simple diffusion.

Answer 32

Channel mediated diffusion

Question 33

The diffusion of water across a selectively permeable membrane

Answer 33

Osmosis

Question 34

The ability of a surrounding solution to cost a cell to gain or lose water

Answer 34

Tonicity

Question 35

It is a solution are solute concentration is the same as the inside of the cell. No net water movement across the plasma membrane has happened

Answer 35

Isotonic solution

Question 36

A solution where solute concentration is greater than that inside the cell where the cell loses water

Answer 36

Hypertonic solution

Question 37

A solution are solute concentration is less than that inside the cell where the cell gains water

Answer 37

Hypotonic solution

Question 38

In a hypotonic solution animal cells become ________, while plant cells become _________.

Answer 38

Lysed, Turgid (normal)

Question 39

In a isotonic solution animal cells become ___________, while plant cells become _________.

Answer 39

Normal, Flaccid

Question 40

In a hypertonic solution animal cells become _________, while plant cells become ___________.

Answer 40

Shriveled, Plasmolyzed

Question 41

It uses energy to move solutes against their gradients

Answer 41

Active transport

Question 42

Give one type of active transport system

Answer 42

Sodium-potassium pump

Question 43

It is the fault age difference across a membrane

Answer 43

Membrane potential

Question 44

To combined forces that drive the diffusion of ions across a membrane

Answer 44

Electrochemical gradient

Question 45

The effect of the membrane potential on the ions movement

Answer 45

Electrical force

Question 46

It is a transport protein that generates voltage across a membrane

Answer 46

Electrogenic pump

Question 47

It is the main electrogenic pump of plants, fungi, and bacteria

Answer 47

Proton pump

Question 48

It is a couple transport by a membrane protein

Answer 48

Cotransport

Question 49

It occurs when active transport of a solute in directly drives transport of other solutes.

Answer 49

Cotransport

Question 50

It occurs by exocytosis and endocytosis. It requires energy

Answer 50

Bulk transport

Question 51

Large molecules such as polysaccharides and proteins cross the membrane in the bulk via

Answer 51

Vesicles

Question 52

Transport vesicles migrate to the membrane, fused with it, and realistic intense. Many secretory cells use this to export their products

Answer 52

Exocytosis

Question 53

The cell takes in macromolecules by forming vesicles from the plasma membrane. It is the reversal of exocytosis.

Answer 53

Endocytosis

Question 54

What are the three types of endocytosis

Answer 54

Phagocytosis Pinocytosis Receptor mediated endocytosis

Question 55

It is also called as cellular eating

Answer 55

Phagocytosis

Question 56

Pinocytosis is also called as

Answer 56

Cellular drinking