Endomembrane system and bulk transport processes

Question 1

Membrane is made up of…

Answer 1

phospholipids

Question 2

Phospholipid

Answer 2

Main component of a membrane. They are a type of lipid molecule. Hydrophilic head and hydrophobic tail.

Question 3

Nuclear envelope

Answer 3

Double-layered membrane that encloses the nucleus. Function- small holes in membrane allow for content to move in and out of nucleus between the cytoplasm.

Question 4

Endoplasmic reticulum

Answer 4

membranous network in eukaryotic cells. rER (with ribosomes) sER (without ribosomes).

Question 5

Golgi body

Answer 5

organelle made up of stacks of flat membranous stacks that modify, store and send products of the ER and can synthesis some products (carbs).

Question 6

Vesicles

Answer 6

a membranous sac in cytoplasm of cell. Transports substances between ER and golgi body

Question 7

Lysosomes

Answer 7

membrane bound, digestive organelle. Contains hydrolytic enzymes (breakdown in acidic env.) Breakdown lipids, proteins, nucleic acids and release products into cell.

Question 8

Vacuoles

Answer 8

Membrane enclosed vesicles derived from rER and golgi body. Has diff. functions.

Question 9

Plasma membrane

Answer 9

membrane of lipids and proteins that surrounds the cytoplasm of cell or encloses vacuole.

Question 10

Smooth ER

Answer 10

associated with the production and metabolism of fats and steroid hormones.

Question 11

Rough ER

Answer 11

involved in protein production, folding, quality control and dispatch.

Question 12

Golgi body functions

Answer 12

Receives, modifies, sorts and ships proteins arriving from the rER. Has polarity; cis (face) and trans (face)

Question 13

Glycosylation

Answer 13

Addition or modification of carbs to proteins.

Question 14

Sorting proteins

Answer 14

Add molecular ‘tabs’ to direct proteins to their correct vesicle before exciting from trans face of golgi.

Question 15

Directing vesicle trafficking

Answer 15

`Add molecular ‘tabs’ to proteins leaving the trans face to direct them to correct targets. e.g to lysosome or secretory pathways.

Question 16

Relationship between golgi body and ER

Answer 16

Golgi body receives proteins made in rER and transports them to required areas of cell via trans face

Question 17

Exocytosis

Answer 17

Transports materials outside of cell (glyco (sugar) proteins to cell surface.

Question 18

Constitutive exocytosis

Answer 18

‘Ongoing’. Releases extracellular matrix proteins (‘goop’ that surrounds the cell’)

Question 19

Regulated exocytosis

Answer 19

Releases hormones and neurotransmitters.

Question 20

Endocytosis

Answer 20

cell “eating” process. Forms a phagocytic vacuole that is digested by lysosome.

Question 21

Phagocytosis

Answer 21

Phagocytes ingest or engulf other cells. Forms phagocytic vacuoles.

Question 22

Pinocytosis

Answer 22

Cell ‘drinking’ process. Uptake of extracellular fluid containing various solutes like proteins and sugars. It is non-selective.

Question 23

Receptor-mediated endocytosis

Answer 23

specialized form of pinocytosis. It is selective. Allows cell to uptake bulk quantities of wanted solutes.

Question 24

Lysosome function

Answer 24

Use interior acidic environment to breakdown substances. They digest and recycle unwanted cellular materials (autophagy).

Question 25

Central vacuole function

Answer 25

Large membrane enclosed organelle present in plant cells. Maintains tugor pressure of plant, plays a limited storage role, and is capable of intracellular digestion.

Question 26

Ribosome

Answer 26

ribosomal RNA and protein molecules that initiate protein synthesis.

Question 27

Phagocytes

Answer 27

Cells that ingests and destroys harmful substances to the cell.