Endomembrane System and Bulk Transport Process

Question 1

What does the endomembrane system include?

Answer 1

• Nuclear envelope
  -Endoplasmic reticulum (smooth and rough)
• Golgi apparatus
• vesicles
  -Lyososomes
  -Vacuoles
  -Plasma membrane

Question 2

What is the endomembrane system

Answer 2

A membrane system interconnected by directed physical contact or transfer by vesicles

Question 3

How to move proteins out of the cell

Answer 3

• Synthesise
  -Tag and package
  -Deliver

Question 4

When you move proteins out of the cell by delivering it,

Answer 4

vesicles transport proteins and cause fuse with membrane of organelles/ the cells

Question 5

Synthesis occurs in

Answer 5

the endoplasmic reticulum

Question 6

The endoplasmic reticulum..

Answer 6

is composed of two regions which is the smooth and rough endoplasmic reticulum.

Question 6

Tag and package occurs in

Answer 6

the golgi apparatus

Question 7

First three functions of the smooth endoplasmic reticulum

Answer 7

• Metabolism of carbohydrates
• Lipid synthesis for membranes
• Detoxification of drugs and poisons

Question 8

Second three functions of the smooth endoplasmic reticulum

Answer 8

• Storage of calcium ions used as a signal in the cell
• Extensive smooth endoplasmic reticulum in cells active in these processes
• The amount of smooth endoplasmic reticulum can be increased or decreased to meet demand

Question 9

First Two functions of rough endoplasmic reticulum

Answer 9

• Rough appearance due to ribosomes
• Involved in protein synthesis

Question 10

Second two functions of the rough endoplasmic reticulum

Answer 10

• Secreted and membrane bound proteins enter the lumen which is the interior of the rough endoplasmic reticulum
• and are processed by the rough endoplasmic reticulum and the rest of the endomembrane system for release from the cell or retention on the cell membrane

Question 11

The golgi complex

Answer 11

Series of membrane sacs and associated vesicles

Question 12

Function of the golgi complex

Answer 12

Receives, modifies, sorts and ships proteins arriving from the rough endoplasmic reticulum

Question 13

The golgi complex has polarity.

Answer 13

• Vesicles form endoplasmic reticulum arrive at the cis face
  -Processed vesicles leave at the trans face

Question 14

Glycosylation

Answer 14

• Addition or modification of carbohydrates to proteins
  -Important for secreted or cell surface proteins
• Golgi also produces many polysaccharides which may also be secreted from the cell

Question 15

Sorting proteins

Answer 15

• Adds molecular markers to direct proteins to the correct vesicles before “budding” from the trans face

Question 16

Directing vesicle trafficking 1

Answer 16

• Adds molecular tags to vesicles leaving the trans face to direct them to the correct targets
• The tags are often short proteins exposed on the vesicle surface

Question 17

Directing vesicle trafficking 2

Answer 17

• Tags direct vesicles to lysosomes, or secretory pathways, or to plasma membrane to add to membrane proteins
  -Act as docking sites when they reach their target

Question 18

Artificial vesicles (liposomes) can be used for..

Answer 18

drug and vaccine delivery

Question 19

types of vesicles

Answer 19

Membrane bound (lipid bilayer), cytoplasm filled organelles

Names reflect function:
- Transport
- Secretory
- Vacuoles

Question 20

Exocytosis

Answer 20

Transports material (glycoproteins) out of the cell or delivers it to the cell surface

Question 20

Bulk transport across the plasma membrane

Answer 20

• Exocytosis
  -Endocytosis
• Phagocytosis
• Pinocytosis
  -Receptor mediated endocytosis

Question 21

Two types of exocytosis

Answer 21

• Constitutive exocytosis
  -Regulated exocytosis

Question 22

Constitutive exocytosis

Answer 22

Releases extracellular matrix proteins

Question 23

Regulated exocytosis

Answer 23

Reles hormones and neurotransmitters

Question 24

Endocytosis

Answer 24

The cell takes in molecules and particulate matter at the plasma membrane

Question 25

Phagocytosis

Answer 25

- Cell eating - Uptake of food particles - Forms a phagocytic vacuole which is digested by the lysosomes - In humans this occurs in macrophages

Question 26

Pinocytosis

Answer 26

- Cell drinking - Uptake of extracellular fluid containing various solutes such as protein and sugars - Up takes vesicles is formed with the aid of a coat protein - Up take is non-selective

Question 27

Receptor mediated endocytosis

Answer 27

- Specialised from of pinocytosis - Allows the cell to take up bulk quantities of specific substances which may be present at only low concentrations in the extracellular fluid - Receptor proteins are used to selectively capture the required solute

Question 28

Phagocytic vacuoles fuse with...

Answer 28

lyososomes

Question 29

Lysosomes are

Answer 29

membrane bound organelles made by the rough endoplasmic reticulum and golgi body containing hydrolytic enzymes

Question 30

The interior of a lysosomes is acidic which is required for..

Answer 30

the enzymes to be active

Question 31

What is required for enzymes to be active

Answer 31

The interior of a lysosomes should be acidic

Question 32

Lysosomes degrade..

Answer 32

proteins, lipids, carbohydrates and nucleic acids and release breakdown products into the cell

Question 33

Lysosomes digest and recycle..

Answer 33

unwanted cellular materials

Question 34

Autophagy is important for cell health. What is it?

Answer 34

Lysosomes digest and recycle unwanted cellular materials

Question 35

Lysosomal digestion is also important in..

Answer 35

programmed cell death in which whole cells "intentionally" die

Question 36

Defects in lyososomal enzymes can result in..

Answer 36

lysosomal storage diseases

Question 37

Food vacuoles are involved in..

Answer 37

phagocytosis

Question 38

Why are vacuoles important in plants

Answer 38

- Can perform lysosome like functions - The large central vacuole absorbs water allowing plant cells to grow without a large increase in cytoplasm

Question 39

Vacuoles are usually the..

Answer 39

largest compartment in a plant cell