transport systems

Question 1

what are the main ways to transport

Answer 1

• facilitated diffusion
  -co transport
  -osmosis
  -active transport
  -carrier proteis
  -chanel proteins

Question 2

describe how diffusion works across a membrane

Answer 2

• movement of particles from a conc of high to low
  -passive process- doesn’t use tap

Question 3

describe facilitated diffusen

Answer 3

• amino acids and glucose (polar molecules)
  -using Chanel and carrier proteins
  -passive

Question 4

describe active transport

Answer 4

• low to high agiinst conc gradient
  -using carrier protiens
  -requies hydrolysis of ATP produced during respiration
  -molecule attaches to the carrier protein which has a specific tertiary structure complementary to the specific molecule that is being transported
  -the binding of the molecule to the carrier protein causes it to change shape so that mol can transport through the membrane

Question 5

what factors can decrease the rate of respiration and so active transport

Answer 5

-low of temp
-low o2

Question 6

describe the use of cholesterol in the plasma membrane

Answer 6

-strength to the membrane as restricts movement of phospholipids

Question 7

describe role of protein across membrane

Answer 7

• act as carriers or Chanels

Question 8

describe the co transport

Answer 8

• movement of substances across cell via carrier protein
• the movement of one molecule is dependant on the movement of the other across the membrane
  -involves facilitated diffusion and active transport t

Question 9

list the steps of co transport

Answer 9

1) sodium ions move out of the cell via active transport using ATP
2) this creates a concentration gradient which forces na ions to move back into the cell via co transport protein which is a carrier protein
3) glucose moves into the cell with na through co transport through carrier proteins
4) once glucose is inside , it is used as energy for respiration.

Question 10

explain the role of channel proteins in facilitated diffusion

Answer 10

• only certion ions can pass through eg, amino acids and glucose ions
• they move down the conc grad
  -passive process

Question 11

Explain why ATP is required for active transport but not for facilitated diffusion.

Answer 11

AT- app is required for active transport as moves mols against conc grad

FD pass process where mols are moved down the conc grad

Question 12

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