Factors affecting membrane structure Flashcards

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1
Q

What are the role of membranes?

A
  • They control the passage of different substances in and out of he cells (and organelles)
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2
Q

What happens if membranes lose their structure?

A
  • They lose control the passage of substances and the cell process will be disrupted.
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3
Q

What happens when temperature is increased?

A
  • The phospholipids will have more kinetic energy and will move more.
  • This makes the membrane more fluid and it begins to lose its structure.
  • If the temperature continues to increase, the cell will eventually break down completely.
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4
Q

What happens to loss of the structure of the membrane?

A
  • Increases permeability of the membrane making it easier for the particles to cross it.
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5
Q

CARRIER AND CHANNEL PROTEINS

A
  • They will be denatured at higher temperatures
  • These proteins are involved in transport across the membrane so as they denature, membrane permeability will be affected.
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6
Q

How does cooling and freezing a membrane will affect its structure?

A
  • Freezing affects the membranes lipids, proteins and nucleic acid by changing the hydrophobic and hydrophillic interactions determining the structure and the function
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7
Q

SOLVENTS

A
  • Water, a polar solvent is essential in the formation of the phospolipid bilayer
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8
Q

NON-POLAR tails

A
  • These are orientated away from the water, forming a bilayer with a hydrophobic core
  • The charged phosphate heads interact with the water, helping to keep the bilayer intact
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9
Q

ORGANIC SOLVENTS

A
  • Many organic solvents are less polar than water (e.g. alcohols)
  • Organic solvents will dissolve the membranes, disrupting the cell
  • Alcohols dissolve the membranes of bacteria in wound, killing them and reducing the risk of infection.
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10
Q

LESS CONCENTRATED SOLUTIONS OF ALCOHOL

A
  • They do not dissolve the membranes.
  • Non-polar alcohol molecules can enter the cell membrane & the presence of these molecules between the phospholipids will disrupt the membranes.
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11
Q

What happens when the MEMBRANE IS DISRUPTED?

A
  • It becomes more fluid and more permeable
  • When neuronal membranes are disrupted, nerve impulses are no longer transmitted as normal.
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