endomembrane system & bulk transport processes

Question 1

endomembrane system

Answer 1

membrane system interconnected by direct physical contact/transfer by vesicles

Question 2

what is endomembrane system comprised of

Answer 2

nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, vesicles, lysosomes, vacuoles, plasma membrane

Question 3

endoplasmic reticulum (ER)

Answer 3

inside the cytoplasm, comprised of 2 regions; smooth ER sER & rough ER rER

Question 4

sER main function

Answer 4

involved in metabolising carbohydrates, synthesising lipids for membrane detoxifying drugs & poison, storage of calcium ions

Question 5

rER functions

Answer 5

involved in protein synthesis, rough appearance due to ribosomes,

Question 6

Golgi complex structure

Answer 6

series of membrane sacs & associated vesicles

Question 7

Golgi complex function

Answer 7

receives, modifies, sorts and ships proteins arriving from rER

Question 8

Golgi complex polarity

Answer 8

has cis-trans faces

• vesicles from endoplasmic reticulum arrive at cis face
• processed vesicles leave via trans face, facing plasma membrane

Question 9

Golgi complex, glycosylation function

Answer 9

addition/modification of carbohydrates to proteins - determining function of protein

Question 10

Golgi complex, sorting protein function

Answer 10

adds molecular markers that direct proteins to correct vesicles before ‘budding’ from trans face

Question 11

Golgi complex, directing vesicle trafficking function

Answer 11

adds molecular ‘tags’ to vesicles leaving the trans face, directing them to correct targets/locations

Question 12

vesicles

Answer 12

membrane bound (lipid bilayer), cytoplasm/fluid filled organelles

Question 13

transport vesicle function

Answer 13

moving things round the cell
eg. ER —> golgi

Question 14

secretory vesicle function

Answer 14

moving to plasma membrane to fuse w it and release contents

Question 15

vacuole function

Answer 15

vesicle structure of plant cells

Question 16

exocytosis

Answer 16

process of transporting material (glycoproteins) to cell surface or out of cell

Question 17

constitutive exocytosis

Answer 17

release extracellular matrix proteins

Question 18

regulated exocytosis

Answer 18

controlled, signal is needed in order for hormones & neurotransmitters to be released

Question 19

endocytosis

Answer 19

cell takes in molecules and particular matter at cell membrane

Question 20

endo - phagocytosis

Answer 20

cell “eating” , uptake of food particles

Question 21

endo - pinocytosis

Answer 21

cell “drinking”, uptake of extracellular fluid containing various solutes eg proteins & sugars

uptake is non-selective, no control of what ends up in created vesicle

Question 22

endo - receptor-mediated endo

Answer 22

form of pinocytosis, allowing cell to take up bulk quantities of specific substances that may be present at only low concs in extracellular fluid

receptor proteins used to selectively capture and bind to required solute

Question 23

lysosome

Answer 23

membrane-bound organelles made by rER & Golgi body containing hydrolytic enzymes
has acidic interior for enzymes to be active

Question 24

lysosome function

Answer 24

phagolytic (eating) vacuoles fuse with lysosomes in order to degrade proteins, lipids, carbohydrates and nucleic acids, and release these breakdown products into cell

Question 25

autophagy

Answer 25

important for cell health, as it digests & recycles unwanted cellular material. lysosomes do this