Cell Bio: Membranous Organells

Question 1

Found in every cell, but the amount may differ depending on the major function of the cell

Answer 1

Membranous organelles

Question 2

Seen in an electron micrograph as a membrane-lined sac

Answer 2

Rough Endoplasmic Reticulum (RER)

Question 3

What is the RER’s outer surface covered with?

Answer 3

Ribosomes

Question 4

What is the RER’s interior region called?

Answer 4

Cisterna

Question 5

What is the membrane of the RER continuous with?

Answer 5

Outer membrane that surrounds the nucleus

Question 6

The RER is present in all cells but where are they particularly abundant?

Answer 6

In cells specializing in protein secretion

Question 7

Proteins synthesized by the RER

Answer 7

• Secretory proteins
• Enzymes of the lysosome
• Proteins that will become part of the membrane proteins of the:
  1. ER
  2. Golgi apparatus
  3. Lysosomes
  4. Plasma membranes

Question 8

Where does post-translational modifications of proteins occur?

Answer 8

Cisternae of the RER

Question 9

Examples of post-translational modifications of proteins

Answer 9

• Folding
• Association of protein subunits

Question 10

Where do the vesicles of the newly synthesized proteins move to?

Answer 10

Membrane of the Golgi

Question 11

What does the golgi do to the newly synthesized protein?

Answer 11

Further modifies

Question 12

Ribosomes are small particles composed of what?

Answer 12

Ribosomal RNA

Question 13

Some ribosomes are attached to what?

Answer 13

RER

Question 14

Ribosomes that aren’t attached to the RER

Answer 14

Free ribosomes

Question 15

What are free ribosomes responsible for?

Answer 15

Formation of proteins used within the cell (various cellular enzymes)

Question 16

Irregular network of smooth channels that appear to be tubular

Answer 16

Smooth Endoplasmic Reticulum (SER)

Question 17

What is SER responsible for?

Answer 17

Synthesis of membrane phospholipids (as well as cholesterol and triglycerides)

Question 18

SER are particularly prominent in cells that do what?

Answer 18

Synthesize steroid hormones

Question 19

SER are found in these type of cells that are exposed to certain drugs

Answer 19

Hepatocytes

Question 20

Enzymes involved in which action is attached to the SER?

Answer 20

Detoxification

Question 21

What is the SER called in muscle cells?

Answer 21

Sarcoplasmic reticulum

Question 22

What is the sarcoplasmic reticulum involved in?

Answer 22

Storage of calcium (necessary for the initiation of muscle contraction)

Question 23

Appear as parallel stack of plate-like membrane compartments

Answer 23

Golgi apparatus

Question 24

Organelle that appears as parallel stack of plate-like membrane compartments

Answer 24

Golgi apparatus

Question 25

Golgi function

Answer 25

**Processing of proteins** that are synthesized on the RER

Question 26

How do the proteins synthesized on the RER reach the golgi?

Answer 26

**Vesicles** containing **secretory products** from the **RER** travel to the **golgi**

Question 27

Where does the addition of carbohydrates to certain AAs (forming glycoproteins) occur?

Answer 27

Golgi

Question 28

What are the proteins modified by the golgi packaged into?

Answer 28

Vesicles or granules

Question 29

Where are the proteins modified by the golgi transported?

Answer 29

Out of the cell (via a signal)

Question 30

What is the plasma membrane constantly doing?

Answer 30

Changing

Question 31

Some vesicles that leave the golgi complex are loaded with digestive enzymes and become incorporated into what?

Answer 31

Lysosomes

Question 32

Membrane enclosed vesicles that contain digestive enzymes

Answer 32

Lysosomes

Question 33

What do lysosomes contain a large number of?

Answer 33

Hydrolases