Membranes

Question 1

Name the membrane component: diffuses quickly and faces the same plane as the membrane

Answer 1

Phospholipids

Question 2

Name the Membrane Component: diffuses slowly, and faces the same plane as the membrane.

Answer 2

Lipids & Proteins (think lipid rafts)

Question 3

Name the Membrane Component: requires flipases to diffuse to the opposite side of a membrane

Answer 3

Phospholipids

Question 4

What are Lipid Rafts made of?

Answer 4

cholesterol & proteins

Question 5

What enzyme allows phospholipids and lipids to flip to face the other side of a membrane, and thus keep them diffusing easily and quickly to even out their concentration all over the membrane?

Answer 5

flipases

Question 6

Why do phospholipids move to areas of the membrane where they’re least concentrated?

Answer 6

they’re diffusing

Question 7

What region of the membrane is made of: proteins, carbohydrates, and phospholipid heads?

Answer 7

the hydrophilic membrane region

Question 8

The ___ ____ membrane creates hydrophilic planes in and outside of cells.

Answer 8

fluid mosaic

Question 9

The membrane is ___ ____.

Answer 9

Selectively Permeable

Question 10

Name the two main types of fatty acids in membranes.

Answer 10

Saturated (each carbon holds as many hydrogens as possible) and Unsaturated (double or triple bonds take the place of where some hydrogens could be bonded to carbons)

Question 11

Why are unsaturated fatty acids harder to “stack” and therefore less solid at room temperature?

Answer 11

their double bonds create a “kink” in the hydrocarbon chain that makes it harder to stack them

Question 12

Adding saturated fatty acids make a membrane ___ fluid, while adding unsaturated fatty acids make the membrane ___ fluid.

Answer 12

less ; more

Question 13

Which type of fatty acid would have a higher melting point?

Answer 13

saturated fatty acids

Question 14

Fatty acids play a role in energy storage by being converted to ___ molecules.

Answer 14

triglyceride

Question 15

What are triglyceride molecules made of?

Answer 15

3 fatty acids attached to a sugar (glycerol) backbone

Question 16

How are triglycerides changed into glycerophospholipids for insertion into membranes?

Answer 16

a fatty acid chain is removed so a negatively charged phosphate group can be added

Question 17

Name the parts of a phospholipid (technically called a glycerophospholipid!)?

Answer 17

2 fatty acids ; 1 glycerol ; 1 phosphate

Question 18

What membrane lipid stabilizes the membrane in extreme heat, and gives it fluidity in the cold?

Answer 18

cholesterol

Question 19

What are the three main types of fats found in the membrane?

Answer 19

Sphingolipids (1) ; Cholesterol (2) ; and Waxes (3)

Question 20

____ ____ can activate or deactivate transporters for facilitated diffusion and active transport.

Answer 20

Membrane Receptors

Question 21

Name 3 primary roles of cholesterol

Answer 21

steroid synthesis ; stabilizing the cell membrane ; increasing cell membrane fluidity

Question 22

What lipids are derived from sphingosine?

Answer 22

sphingolipids

Question 23

Phospholipids have __ less fatty acids than triacylglycerol.

Answer 23

1

Question 24

What type of fat increases rigidity in plant cells membranes by stabilizing the hydrophobic region of the cells’ membranes?

Answer 24

waxes

Question 25

What are waxes composed of?

Answer 25

a long fatty acid chain with a long chain ester

Question 26

Name the 4 types of sphingolipids found in a cell membrane?

Answer 26

ceramides, sphingomyelin, cerebrosides, and gangliosides

Question 27

Where do sphingolipids differ from phospholipids (region)?

Answer 27

in their hydrophilic region (they have an ester long chain instead of a sugar and phosphate)

Question 28

What is the point of sphingolipids?

Answer 28

to yield biologically important (necessary) lipids: ceramides, sphingomyelin, cerebrosides, and gangliosides

Question 29

Name the 4 major molecular components of the cell membrane.

Answer 29

Proteins ; Carbohydrates ; Membrane Receptors ; Cell-Cell Junctions

Question 30

___ (a major membrane component) are important for forming biofilms and cell membrane communication and messaging.

Answer 30

carbohydrates

Question 31

Name the 3 major types of membrane proteins.

Answer 31

Integral Proteins (Transmembrane & Embedded, I think?) and Peripheral (Membrane Associated)

Question 32

Are transmembrane and embedded proteins both integral proteins?

Answer 32

idk ask

Question 33

What type of membrane protein is Cytochrome C? (Hint: it's vital for making ATP)

Answer 33

it's a membrane-associated (peripheral) protein

Question 34

What type of membrane protein is Cytochrome C Oxidase?

Answer 34

Membrane-Associated (peripheral) protein

Question 35

What type of membrane protein goes through both ends of a membrane, and likely carries out tasks on both sides?

Answer 35

Transmembrane Proteins

Question 36

What type of membrane protein is an Aquaporin?

Answer 36

transmembrane protein

Question 37

What kind of membrane protein is the Sodium-K Pump?

Answer 37

transmembrane protein

Question 38

What kind of membrane proteins are chloride channels?

Answer 38

transmembrane proteins

Question 39

What kind of membrane protein is found on the outer edges of the membrane and is not associated with the membrane's interior?

Answer 39

Membrane-Associated (Peripheral) Proteins

Question 40

What kind of membrane protein can associate with the interior or exterior of a cell membrane, but not both?

Answer 40

Embedded Proteins

Question 41

What kind of membrane protein are prostaglandin syntheses 1 and 2? (Hint: these make the proteins that cause smooth muscle contraction in the outer bilayer.)

Answer 41

Embedded Proteins

Question 42

Why are membrane carbohydrates generally hydrophilic?

Answer 42

they tend to have lots of oxygen molecules

Question 43

What types of carbohydrates tend to attach to proteins on extracellular surfaces?

Answer 43

membrane carbohydrates

Question 44

True / False: membrane carbohydrates form the cell coats found in biofilms, which compose plaques on our teeth?

Answer 44

True!

Question 45

True / False: Blood types come from surface carbohydrates!

Answer 45

true!

Question 46

___ (membrane component molecule) can be recognized by both the immune system and microbes.

Answer 46

True!

Question 47

Name the 3 types of cell-cell membrane junctions.

Answer 47

Gap Junctions (1) ; Desmosomes (2) ; and Tight Junctions (3)

Question 48

In __ diffusion, permeable (?) substances follow their concentration gradients across the membrane.

Answer 48

Simple Diffusion (a type of passive transport)

Question 49

In ___ diffusion, energy could be supplied by concentration gradients or entropy changes, but NOT ATP.

Answer 49

Simple Diffusion

Question 50

Can water move along it's own concentration gradient?

Answer 50

yes

Question 51

What is Osmosis?

Answer 51

diffusion of water

Question 52

When the solute concentration is equal inside and outside of a cell, what kind of state is the cell in?

Answer 52

Isotonic

Question 53

True / False: If the environment around a cell is hypotonic, then that cell has a lower water concentration than it's surroundings.

Answer 53

True!

Question 54

True / False: If the environment around a cell is hypertonic, then that cell has a higher water concentration than it's surroundings.

Answer 54

True!

Question 55

____ ____ (pi) is the driving force behind osmosis.

Answer 55

Osmotic Pressure (Pi)

Question 56

Is Osmotic Pressure (Pi) a colligative property?

Answer 56

Yes

Question 57

What is the formula for Osmotic Pressure (Pi)?

Answer 57

``` Pi = iMRT i = Van't Hoff Factor (number of particles that dissociate into solution) because Osmotic Pressure is a colligative property M = Molarity R = Ideal Gas Constant T = Temperature in Kelvin ```

Question 58

How can you quickly tell which solution of ions will have the highest or lowest ionic pressure?

Answer 58

the solution that dissociates into the most ions with the highest molarity will have the highest ionic pressure

Question 59

___ ___ uses membrane proteins to transport molecules that are otherwise impermeable to the membrane.

Answer 59

Facilitated Diffusion

Question 60

The ___ ___ of the cell membrane is too high for large / polar / charged molecules to pass through it freely so that a membrane protein is needed to help these across.

Answer 60

Energy Barrier

Question 61

What type of transport could move ions across a membrane without the input of energy?

Answer 61

Facilitated Diffusion ; sodium ions are impermeable, so you need a protein to transport them

Question 62

What is Simple Diffusion in reference to solute transport across membranes?

Answer 62

small, non polar molecules (like diatomic oxygen and carbon dioxide) are able to diffuse across the membrane according to their concentration gradients.

Question 63

In what type of transport does water move down it's own concentration gradient across the membrane through specialized proteins? Hint: water always moves aganst the concentration gradient of solute.

Answer 63

Osmosis

Question 64

Water always moves (with / against) the concentration gradient of the solute.

Answer 64

AGAINST

Question 65

For ___ ___ the solute still moves across the membrane down it's concentration gradient (no ATP is used), but needs to travel through a protein channel or a carrier protein because it is impermeable to the membrane.

Answer 65

Facilitated Diffusion

Question 66

Symport and Antiport are two processes associated with what kind of solute transport across membranes?

Answer 66

Secondary Active Transport

Question 67

What is Symport?

Answer 67

a type of secondary active transport in which the particles being moved are moving in the same direction across the membrane

Question 68

What is Antiport?

Answer 68

a type of secondary active transport in which the particles are moving in opposite directions across the membrane

Question 69

What are the two types of active transport?

Answer 69

Primary Active Transport: uses ATP Secondary Active Transport: uses one molecule flowing down it's concentration gradient to fuel transporting another molecule going against it's concentration gradient

Question 70

EX: Na+ ions are flowing down their concentration gradient through a membrane protein, that uses this flow to move in an amino acid against it's concentration gradient (in the opposite direction of the sodium ions). What type of transport is this?

Answer 70

Secondary Active Transport: the Na+ concentration gradient fuels the amino acid going against it's own gradient.

Question 71

What is the driving energy source behind secondary active transport, since ATP cannot be used to fuel it?

Answer 71

the entropy change of allowing a solute to go with it's concentration gradient (same driving force as facilitated diffusion and passive transport!)

Question 72

What is Primary Active Transport? What proteins does it typically use?

Answer 72

a type of active transport (moves solute against it's concentration gradient) using ATP as it's fuel ; typically done using transmembrane ATPases (the membranes that accomplish this are called this???)

Question 73

What is Secondary Active Transport?

Answer 73

a type of active transport (moves solute against it's concentration gradient) using the energy from the entropy change of ANOTHER molecule flowing down (with) it's concentration gradient

Question 74

What's our quick and dirty way to see what solute has the most osmotic pressure?

Answer 74

look at it's molarity and the number of ions it will dissociate into, that quantity (roughly multiplied) is directly proportional to osmotic pressure!!

Question 75

Osmosis is driven by ___ ___.

Answer 75

Osmotic Pressure

Question 76

While passive transport is driven by entropy change, what drives active transport? (in terms of energetic quantities)

Answer 76

enthalpy and temperature

Question 77

Facilitated Diffusion transports impermeable solute across membranes using what two proteins?

Answer 77

Protein Channels: can be open or closed in response to diverse signals Carrier Proteins: work like revolving doors so that a solute enters from one side, and the protein shuts behind it before opening it's other side to let the solute exit

Question 78

What is the Occluded State? Hint: it applies to Carrier Proteins.

Answer 78

the occluded state is when the protein is not open to either side. this state occurs in between letting the protein enter and letting it exit. Remember, revolving door.

Question 79

True / False: gong down one's concentration gradient creates more disorder (S) and is therefore favorable.

Answer 79

hell yasss

Question 80

True / False: as temperature increases so does the rate of passive transport!

Answer 80

True

Question 81

Delta G is negative and positive for what kinds of transport, respectively?

Answer 81

delta G is negative for favorable processes, no energy input, spontaneous = Passive Transport Delta G is positive for non spontaneous processes, need energy input, non spontaneous = Active Transport

Question 82

White blood cells eating pathogens is exocytosis or endocytosis? Specify.

Answer 82

endocytosis, specifically phagocytosis

Question 83

Neurotransmitter release at the synapse is an example of exocytosis or endocytosis?

Answer 83

Exocytosis

Question 84

There are tow main reasons that a cell would choose endo/exocytosis for transport. Name them

Answer 84

the particles being transported are: - too big to be transported by a protein - too big of a quantity to effectively transport any other way

Question 85

What is Pinocytosis?

Answer 85

the cell is getting fluids and dissolved compounds

Question 86

What is Phagocytosis?

Answer 86

pac man ; cells eats solids

Question 87

Do phagocycotis and pinocytosis use vesicles?

Answer 87

yes ; vesciles are necessary for this process