Vascula transport in cells\

Question 1

movement of small substances across membrane

Answer 1

simple diffusion
channels
carrier proteins

Question 2

describe simple diffusion

Answer 2

small non-polar molecules pass directly thru the lemma

Question 3

what moves faster and slower by diffusion

Answer 3

lipophilic substances ( water slow )

Question 4

describe channels & movement by channels

Answer 4

multipass proteins from translemma pores allowing small molecules mainly ions to pass through

Question 5

aquaporins

Answer 5

-proteins channels for water

Question 6

describe carriers and movement by carriers

Answer 6

transmembrane proteins bind to small water solube molecules and transcolate them by conformational changes

Question 7

energy for diffusion, channel and carrier

Answer 7

-substances moves via their own kinetic energy down a conc grad

Question 8

contrast to passive methods

Answer 8

-membrane pumps which r enzymes for active transports that move substances against conc grad with energy form ATP hydrolysis

Question 9

how are large molecules moves

Answer 9

• endocytosis ( into cell )

- exocytosis ( out of cell )

Question 10

3 types of endocytosis

Answer 10

• phagocytois
• pinocytosis
• receptor mediated endocytosis`

Question 11

describe phagocytosis, where prominent and type of substances taken in

Answer 11

• cell extends cytoplasmic and membrane folds called pseudopodia which surround particle and infuse around it engulfing it into cell as phagosome
• engulf bacteria or dead cell remanants
• prominent in macrophages

Question 12

what is phagocytosis dependant on

Answer 12

-cytoskeletal changes

Question 13

describe pinocytosis and use

Answer 13

-small invaginations of cell lemma an dcyto wc fuse and trap ecm fluid and its dissolved paticles. the pit then pinches inward into cell forming pinocytotic vescicle

bulk transport of substances across cell as vescicle can fuse with membrane from other side of cell and relase contents ( transcytosis )

Question 14

receptor mediated describe

Answer 14

-ligands ( susbtances with high affinity for receptors ) bind to receptors ( membrane receptors ) forming receptor ligand complex. when many are bound they aggregate in one membrane region ( attach to adapter protein which then attaches to clathrin coat forming coated pit), invaginate ( due to clathrin ) and pinch off inwardly(due to dynamins which surround and pinch of membrane)

Question 15

fate of endosomes

Answer 15

-Endosomes enters cell as coated vacuole
-coat proteins leave vacuole and are recycled
-endosomes then becomes early endosome ( ligand-receptor complex detaches and vacuole splits into 2 )
-vacuole with receptors recycled
-vacule with ligands is now late endosomes wc will either
1 transcytosis
2 fuse with lysosome