Intracellular trafficking

Question 1

what 2 places are ribosomes found?

Answer 1

• rough endoplasmic reticulum (RER)
• free in the cytoplasm

Question 2

what ribosomes are responsible for the production of proteins for the nucleus and mitochondria?

Answer 2

made by cytoplasmic ribosomes

Question 3

what ribosomes are responsible for the production of proteins for everything BUT the nucleus and mitochondria?

Answer 3

made by the RER ribosomes

Question 4

what percentage of the total cell volume is the cytosol?

Answer 4

50-60%

Question 5

why don’t proteins destined for the cytosol have any signals?

Answer 5

• made from cytoplasmic ribosomes
• already in the cytosol

Question 6

what do cytoplasmic proteins need in order to interact with other proteins?

Answer 6

• short amino acid sequences
• specific binding domains or regions on their surfaces

Question 7

what percentage of the total cell volume is the mitochondria?

Answer 7

20%

Question 8

what percentage of the total cell volume is the rough ER cisternae?

Answer 8

10%

Question 9

what percentage of the total cell volume is the smooth ER cisternae + golgi cisternae?

Answer 9

6%

Question 10

what percentage of the total cell volume is the nucleus?

Answer 10

6%

Question 11

what percentage of the total cell volume is the peroxisomes?

Answer 11

1%

Question 12

what percentage of the total cell volume is the lysosomes?

Answer 12

1%

Question 13

what percentage of the total cell volume is the endosomes?

Answer 13

1%

Question 14

what is the function of the mitochondria?

Answer 14

to generate energy in the form of ATP through cellular respiration

Question 15

what is the endoplasmic reticulum?
what 3 things is the ER crutial for?

Answer 15

• a network of membranes within eukaryotic cells
• acting as a crucial organelle for protein synthesis, lipid metabolism, and calcium storage

Question 16

what are the 2 forms of endoplasmic reticulum? what is the difference?

Answer 16

• rough ER (RER): with ribosomes for protein processing
• smooth ER (SER): involved in lipid metabolism

Question 17

what are lysosomes?

Answer 17

• A membrane-bound cell organelle that contains digestive enzymes.
• They break down excess or worn-out cell parts.
• They may be used to destroy invading viruses and bacteria.

Question 18

what are peroxisomes?

Answer 18

small, membrane-enclosed organelles that contain enzymes involved in a variety of metabolic reactions, including several aspects of energy metabolism.

Question 19

what are endosomes?

Answer 19

Endosomes are intracellular sorting organelles in eukaryotic cells that transport proteins and lipid

Question 20

what does traffic refer to in cells?

Answer 20

the movement of proteins and lipids within and between cellular compartments