2.Crossing the plasma membrane Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what elements are in lipids

A

CHO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Lipids vs Carbohydrates

A

-Lipids contain a lot less oxygens compared to carbohydrates (lipids have long chains made up of C and H entirely)
-Lipids are non polar and insoluble in water whereas carbohydrates are polar and soluble in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List 3 characteristics of lipids

A

-exist as fats, oils and waxes
-poor conductors of heats
-good insulators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Examples of triglycerides

A

Fats
Oils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Subunits of triglycerides

A

Glycerol and 3 fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what bonds exist within triglycerides

A

ester bond between glycerol and fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is glycerol

A

-Glycerol forms the base of triglycerides
-Contain 3 hydroxyl groups (OH)
-Fatty acids attach to the hydroxyl (OH) groups of glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are fatty acids

A

-Fatty acids are very long molecules
-They can be hundreds of carbons long (usually 10-100)
-They attach to glycerol via there carboxyl group (COOH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Saturated vs Unsaturated fats

A

Saturated fats contain NO double bonds between carbon atoms (hence saturated with hydrogen) whereas unsaturated fats have at least one Carbon carbon double bond.
(mono=one C,C double bond, poly=many C,C double bonds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List any 4 functions of triglycerides

A

-Energy source
-Protection of vital organs
-To prevent evaporation in plants
-To insulate the body
-Forms myelin sheath around the axons of neurones
-metabolic water source (as a result of respiration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what elements are in phospholipids

A

CHO P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

structural components of phospholipids

A

glycerol, 2 fatty acids and a phosphate head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cholesterol function

A

provides stability and flexibility to the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are steroids

A

-steroids are lipid based hormones
-steroids are signalling molecules that cause a response within the body
-lipid based hormones (steroids) are lipid soluble, hence can simply cross the phospholipid bilayer and have an intracellular receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

components of plasma membrane

A

-two sets of phospholipids (label individual components)
-protein channel
-glycolipid
-protein pump
-cholesterol
-glycoprotein
-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are phospholipids arranged in the plasma membrane

A

-polar hydrophilic (water loving) phosphate head faces aqueous solutions
-two non polar/hydrophobic fatty acid tails point towards the centre of the phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

glycoprotein

A

carbohydrate chain (hexagonal shape) attached to protein

18
Q

glycolipid

A

carbohydrate chain (hexagonal shape) attached to PHOSPHOlipid

19
Q

Diffusion

A

the net movement of particles from area of high to low concentration down a concentration gradient.
(passive)

20
Q

Factors that effect the rate of diffusion

A

general factors:
-temperature-particles with greater kinetic energy diffuse faster
-particle size-particles with lower mass move with greater kinetic energy (at the same temperature) and can move through smaller pores in the membrane

Specific to movement across the membrane:
-Concentration gradient-greater the difference in concentration on either side of the membrane, diffusion will occur faster
-Diffusion distance-if the semi permeable membrane is thinner, diffusion will occur faster
-surface area- larger surface area means more particles can move across the membrane simultaneously

21
Q

Fluid mosaic theory

A

-membranes are made up of small components-mosaic
-components are free to move independently of each other-fluid

22
Q

what substances can cross directly through the phospholipid bilayer

A

-Small gases:02,CO2
-Small non polar molecules:urea, ethanol
-Lipid soluble molecules:steroids, vitamin D
-Water

23
Q

How can you measure diffusion

A

using a colorimeter, the more pigment that diffuses out into surrounding fluid, the less light that will get through the liquid (more is absorbed) and hence more diffusion.

24
Q

osmosis

A

Osmosis- the net movement of water molecules from an area of high water/solvent concentration through a partially permeable membrane to an area of low water/solvent concentration.

25
Q

solution

A

solvent + solute

26
Q

solvent

A

water- universal solvent

27
Q

Hypotonic solution

A

-solution lower in solute and higher in water molecules than the solution being compared to

28
Q

Hypertonic solution

A

-solution higher in solute and lower in water molecules than the solution being compared to

29
Q

isotonic solution

A

-two solutions of equal solute concentration
(no net movement of water)

30
Q

animal cell in hypotonic solution

A

cell lyses/becomes lysed

31
Q

animal cell in hypertonic solution

A

cell crenates/ becomes crenated

32
Q

plant cell in hypotonic solution

A

cell is turgid

33
Q

plant cell in isotonic solution

A

cell is flaccid

34
Q

plant cell in hypertonic solution

A

cell is plasmolyzed

35
Q

Facilitated diffusion

A

The net movement of particles from high to low concentration down a concentration gradient using a protein channel

36
Q

Active transport

A

The movement of DISSOLVED substances ACROSS a membrane from low to high concentration using ATP and a protein pump

37
Q

Exocytosis
+eg

A

Bulk movement of large molecules OUT of the cell. Vesicles fuse with the cell membrane and expel their contents out of the cell.
eg release of hormones in glands of the endocrine system

38
Q

Endocytosis

A

Bulk movement of large molecules into the cell. Substances hit the cell membrane triggering the formation of vesicles inside the cell

39
Q

Pinocytosis
+eg

A

Bulk movement of liquids into the cell
eg how paramecium feeds

40
Q

Phagocytosis
+eg

A

Bulk movement of solids into the cell
eg. WBC engulfs a pathogen

41
Q

Phagocytosis steps

A
  1. Phagocyte engulfs pathogen
    -vesicle formed around pathogen (phagosome)
  2. Pathogen destroyed
    -lysosome and phagosome fuse together (phagolysosome)
    -digestive enzymes break down pathogen
  3. Exocytosis occurs
    -Phagolysosome fuses with membrane, removing unwanted cellular material
42
Q

two types of endocytosis

A

pinocytosis
phagocytosis