Unit 1- The cell membrane Flashcards

1
Q

what is the fluid mosaic model

A

the cell membrane
-lipid bilayer
-proteins within
*not ridgid, lipids and proteins can move laterally

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2
Q

what factors make the phospholipid bilayer FLUID

A

-the fatty acid chains of phospholipids (unstaurated)
-temp (high, more fluid) (cold, less fluid)
-Sterols (cholesterol regulates temp, making sure it doesn’t become too hot not too cold)

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3
Q

what factors make the phospholipid bilayer SEMIPERMEABLE

A

-hydrophobic core prevents hydrophilic structures but allows hydrophobic structures

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4
Q

what are integral proteins

A

proteins that span the lipid bilayer

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5
Q

where are proteins placed within the cell membrane

A
  1. non-polar regions of the protein are in the interior bilayer
  2. polar regions of the protein protrude both sides of the bilayer
    3.
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6
Q

what is a glycolipid

A

lipid with a carbohydrate chain attached to it on the extracellular surface of the cell

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7
Q

what is a glycoprotein

A

a protein with an extra carbohydrate attached to it on the surface of the cell

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8
Q

what are functions of glycoproteins and glycolipids

A

-receptors
-cell recognition
-hormonal responses
-neurotransmission

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9
Q

what are the criteria for passive transport

A

-small nonpolar molecule
-high & low concentration
-no use of chem energy

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10
Q

what are the 4 types of passive transport

A

-simple diffusion
-facilitated diffusion
-osmosis

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11
Q

what is simple diffusion

what can pass through

A

-molecules pass through bilipid layer

-small nonpolar molecules (O2, CO2, N2)
-small polar molecules (H2O, glycerol)

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12
Q

what is facilitated diffusion

A

-molecules move with the help of transportive proteins

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13
Q

what are the two transportive proteins

A

-channel proteins- like tunnels

-carrier proteins- like elevators

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14
Q

what is osmosis

what can pass through

A

-water molecules pass directly through the lipid bilayer or through a pore

-water

*Moves from high concentration to low concentration

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15
Q

how does water move

A

water always moves towards hyper solution (high solute)

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16
Q

what is a hypotonic solution

what happens to the cell

A

-concentration lowwqh outside cell, concentration high inside cell
-water moves into cell

-cell cannot hold that much water to it lyses (bursts)

17
Q

what is a isotonic solution

what happens to the cell

A

-the concentration is the same outside and inside the cell

-the cell stays normal

18
Q

what is a hypertonic solution

what happens to the cell

A

-concentration outside the cell is higher, concentration inside the cell is low

-the cell shrivels

19
Q

what is a diseases relating to defective channel proteins

A

cystic fibrosis

-channel protein does not move chloride ions
-causes thick, sticky, mucus

20
Q

what is a diseases relating to defective carrier proteins

A

cystin urea

21
Q

when does active transport occur

A

when substances must travel against the concentration gradient (travel from lower to higher)

22
Q

what does active transport require

A

-pumps
-energy (ATP)

23
Q

what does ATP stand for

where does it’s energy come from

A

adenosine tri-phosphate

energy stored in bonds connecting phosphate molecules together (Phosphates are super -ve and want to push away from eachother)

24
Q

what is primary active transport

A

-uses ATP to power pumps that move molecules across membrane against the concentration gradient
-positively charged ions

25
what is the electrochemical gradient
difference in electrical potential and difference in concentration gradients
26
what are peripheral membrane proteins
proteins anchored to a phospholipid in one layer of the membrane
27
what do peripheral membrane proteins do
-receptor recognition -cell signaling -carry electrons
28
what is secondary active transport
transport of molecules across the cell membrane using energy other then ATP, energy from the electrochemical gradient
29
what are the stages of secondary active transport
1. sodium ions move low [ ] to high [ ] using a Na/K pump -this creates a build up of Na ions outside the cell creating an electrochemical gradient 2. Na ions want to move high [ ] to low [ ]. They take glucose along
30
what is symport
substances moving through cell membrane pull other substances through cell membrane in SAME direction
31
what is symport
substances moving through cell membrane pull other substances through cell membrane in SAME direction
32
what is anti port
when substances moving through the membrane and pull other substances through the cell membrane the opposite direction