Cell membranes Flashcards Preview

Biology Units 1 & 2 Study > Cell membranes > Flashcards

Flashcards in Cell membranes Deck (23)
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1
Q

What is proteins role in the cell membrane?

A

To move large or charged molecules across the membrane

2
Q

What is cholesterols role in the cell membrane?

A

Stability and fluidity

3
Q

What are carbohydrates role in the cell membrane?

A

Makes the cell its attached to recognisable to things outside the cell

4
Q

What is the phospholipid bilayers role in the cell membrane?

A

It provides a barrier between the cytoplasm and outside the cell

5
Q

What is a hypertonic solution?

A
  • Low H2O outside
  • H20 flows out of the cell, pressure drops
  • Cell becomes dehydrated and shrivels up in animals, vacuole shrinks in plants
6
Q

What is a hypotonic solution?

A
  • High H2O outside
  • H2O flows into cells
  • Pressure builds up, cells burst in animals, in plants, they become turgid due to cell wall
7
Q

What is an isotonic solution?

A
  • No change in cell
  • H2O moves in and out at the same rate
  • the H2O concentration outside the cell is equal to the H2O concentration inside the cell
8
Q

What is diffusion?

A

Movement of a solute from a high concentration to low concentration.

9
Q

What is osmosis?

A

Diffusion involving water passing through a selectively permeable membrane. Moving from a high to low concentration

10
Q

What molecules can diffuse across the membrane in diffusion?

A

Oxygen and carbon dioxide

11
Q

What is active transport?

A
  • Involves channel proteins and a source of energy/ ATP
  • Requires ATP to move materials across the cell membrane against the concentration gradient
12
Q

What is facilitated diffusion?

A

Substances are helped across the cell membrane via passive channel molecules. Moves from low to high concentration

13
Q

What substances move across the membrane via facilitated diffusion?

A

larger molecules like sugar, amino acid, nucleotides, charged ions and nutrients

14
Q

What does semipermeable mean?

A

Only lets some things pass and not others

15
Q

What are phospholipids?

A

bulk of membrane, creates barrier between intracellular and extracellular fluid

16
Q

What are the three types of passive transport?

A

Simple diffusion, osmosis and facilitated diffusion

17
Q

What is endocytosis?

A
  • Bulk transport in
  • A cell extenss its plasma membrane around substances and engulfs them, moving the substance into the cell
  • Involves vesticles
18
Q

What is exocytosis?

A
  • Bulk transport out
  • Excreting materials from a cell
  • The materials are packaged in vesicles
  • The cell uses ATP energy
19
Q

What are peripheral proteins?

A

Receptors that binds to marker to receive a hormone or signal to make a reaction within the cell

20
Q

What is a channel protein used in?

A

Facilitated diffusion

21
Q

What is a carrier protein used for?

A

Active transport

22
Q

is the phosphate head of of the phospholipid bilayer hydrophilic or hydrophobic?

A

polar/ hydrophilic

23
Q

are the fatty acid tails of the phospholipid bi layer hydrophilic or hydrophobic?

A

non-polar/ hydrophobic