MCBM 1- Cell Structure and Function
Questions and Answers 100% Correct
What are ribosomes formed by? What kind of stain will it show up on? Why? - ANSWER -
Formed by multiple protein subunits and rRNA. Basophilic, will show up on a hemotoxylin stain!
Discuss free ribosomes. What kind of proteins do they synthesize? What can free ribosomes do
in regards to protein translation? - ANSWER - Free ribosomes will find RNA and translate
proteins which function in the cytoplasm, nucleus, mitochondria, or are peroxisomes.
They can translate multiple proteins at the same time. Called "Polysomes" (free ribosomes
grouped along a single strand of mRNA).
Discuss bound ribosomes. Where are they bound? What kind of proteins do they synthesize? -
ANSWER - Bound ribosomes are on Rough ER.
Synthesize proteins destined to be secreted, integrated into membranes, or located within
lysosomes.
Discuss Smooth ER. What is its structure? What kind of processes is it involved in? - ANSWER
- It is more tubular in structure.
NO PROTEIN SYNTHESIS
Involved in lipid synthesis, cholesterol synthesis, other steroid synthesis, degredation of toxic
compounds, production of gastric HCL, and sequestration of Ca++ in muscle cells.
Discuss Lysosomes. What are the involved in? What do they contain? - ANSWER - Vesicles are
involved in the breakdown of material taken up from outside the cell or self cellular material
(autophagy).
Contain hydrolytic enzymes and have a low pH.
, What is Tay Sach's disease? - ANSWER - When lysozymes malfunction, they can lead to
lysozomal storage disfunctions which lead to undigested material accumulating in the cell.
What will preferentially stain lysosomes? - ANSWER - Acid-phosphatase
Discuss Rough ER. What is its structure? What kind of processes is it involved in? What is the
significance of Rough ER in respect to glycosylation? - ANSWER - Rough ER is studded on the
surface by membrane bound ribosomes.
It is the site of synthesis of proteins destined for export out of the cell.
Glycosylation starts in rough ER and is continued within the Golgi apparatus.
What is co-translational transport? - ANSWER - This is the process of proteins getting
synthesized, getting fed through pores into the cisternae of the rough ER.
The following is an image of Rough ER. - ANSWER - Note the cristae and mitochondria.
The following is an image of Smooth ER. - ANSWER -
Discuss the cis-cisternae of the Golgi apparatus. What is it close to? What is its function? What
is this relationship called? - ANSWER - Cis cisternae is close to the Rough ER.
They receive vesicles of protein destined for export from the Rough ER.
This transport is called the cis-Golgi network.
Discuss trans cisternae. What is its function? What are the 3 main destinations for vesicles
leaving the trans-Golgi network? - ANSWER - Site where most of the sorting and packaging of
vesicles of mature proteins takes place.
Questions and Answers 100% Correct
What are ribosomes formed by? What kind of stain will it show up on? Why? - ANSWER -
Formed by multiple protein subunits and rRNA. Basophilic, will show up on a hemotoxylin stain!
Discuss free ribosomes. What kind of proteins do they synthesize? What can free ribosomes do
in regards to protein translation? - ANSWER - Free ribosomes will find RNA and translate
proteins which function in the cytoplasm, nucleus, mitochondria, or are peroxisomes.
They can translate multiple proteins at the same time. Called "Polysomes" (free ribosomes
grouped along a single strand of mRNA).
Discuss bound ribosomes. Where are they bound? What kind of proteins do they synthesize? -
ANSWER - Bound ribosomes are on Rough ER.
Synthesize proteins destined to be secreted, integrated into membranes, or located within
lysosomes.
Discuss Smooth ER. What is its structure? What kind of processes is it involved in? - ANSWER
- It is more tubular in structure.
NO PROTEIN SYNTHESIS
Involved in lipid synthesis, cholesterol synthesis, other steroid synthesis, degredation of toxic
compounds, production of gastric HCL, and sequestration of Ca++ in muscle cells.
Discuss Lysosomes. What are the involved in? What do they contain? - ANSWER - Vesicles are
involved in the breakdown of material taken up from outside the cell or self cellular material
(autophagy).
Contain hydrolytic enzymes and have a low pH.
, What is Tay Sach's disease? - ANSWER - When lysozymes malfunction, they can lead to
lysozomal storage disfunctions which lead to undigested material accumulating in the cell.
What will preferentially stain lysosomes? - ANSWER - Acid-phosphatase
Discuss Rough ER. What is its structure? What kind of processes is it involved in? What is the
significance of Rough ER in respect to glycosylation? - ANSWER - Rough ER is studded on the
surface by membrane bound ribosomes.
It is the site of synthesis of proteins destined for export out of the cell.
Glycosylation starts in rough ER and is continued within the Golgi apparatus.
What is co-translational transport? - ANSWER - This is the process of proteins getting
synthesized, getting fed through pores into the cisternae of the rough ER.
The following is an image of Rough ER. - ANSWER - Note the cristae and mitochondria.
The following is an image of Smooth ER. - ANSWER -
Discuss the cis-cisternae of the Golgi apparatus. What is it close to? What is its function? What
is this relationship called? - ANSWER - Cis cisternae is close to the Rough ER.
They receive vesicles of protein destined for export from the Rough ER.
This transport is called the cis-Golgi network.
Discuss trans cisternae. What is its function? What are the 3 main destinations for vesicles
leaving the trans-Golgi network? - ANSWER - Site where most of the sorting and packaging of
vesicles of mature proteins takes place.
