DSA Organelles

Question 1

The outer boundary of cells is the _

What are its functions?

Answer 1

Plasma Membrane

Protective barrier, Transportation, Signaling

Question 2

This organelle contains the genome.

It is the principial site for what?

Answer 2

Nucleus

DNA and RNA synthesis

Question 3

This consists of the cytosol and cytoplasmic organelles

Answer 3

Cytoplasm

Question 4

What is the difference between the two types of Endoplasmic Reticulum (ER)?

What is it involved with?

Answer 4

• Rough ER has ribosomes attached to it, Smooth ER has no ribosomes
• Protein and Lipid synthesis, Protein folding, and Calcium storage

Question 5

This organelle is stacks of disc like compartments

What is it involved with?

Answer 5

Golgi Apparatus

Post-Transitional Changes and Protein Trafficking

Question 6

Functions of the Mitochondria

Answer 6

Making ATP

Signaling

Cell Differentiation

Cell Death

Question 7

This organelle contains digestive enzymes that degrade organelles and biomolecules

Answer 7

Lysosomes

Question 8

This organelle has small vesicular compartments that contain enzymes used in oxidation reactions

Answer 8

Peroxisomes

Question 9

The cell is divided into 3 Topological categories

Answer 9

• Nucleus and cytosol
  
  • ​Communicate through nuclear pore complex
• Organelles in secretory and endocytic pathways (ER, Golgi Apparatus, Endosomes, Lysosomes)
  
  • ​Communicate though vesicles
• Mitochondria

Question 10

Topologically Equivalnet Organelles

What allows the lumen of these compartments to communicate with each other and with the cell exterior?

Answer 10

Membrane budding and fusion

Question 11

The ER divides the cytoplasm into two compartments

Answer 11

Luminal (cisternal compartment) & Cytoplasmic (cytosolic compartment)

Question 12

Rough ER

What makes this organelle unique from Smooth ER?

What type of cells have lots of RER?

Answer 12

Presence of ribosomes

Cells that make secreted proteins

Question 13

The mechanism by which secretory proteins are directed to the ER is explained by the _

Answer 13

Signal sequence

Question 14

Most proteins exit the RER in vesicles transported to where?

Answer 14

Cis portion of the Golgi apparatus

Question 15

Smooth ER

Different from RER in what two ways?

Important functions include?

It is abundant in cells that make what?

Answer 15

Lacks ribosomes and has tubular cisternae

Lipid & Phospholipid Synthesis, Detoxification

Cells that make steroids or lipids

Question 16

Golgi Apparatus

What are the two distinct faces and what structures do they face?

Answer 16

Cis-Golgi (entry face) is adjacent to ER

Trans-Golgi (exit face) points toward plasma membrane

Question 17

Golgi Apparatus Functions

Answer 17

• CHO modification attached to glycoproteins and proteoglycans
• Poly- and oligosaccharide synthesis
• Sphingomyelin and glycosphingolipid synthesis
• Sorting Secretory Products
  
  • Ex: Marking lysosomal enzymes with M6P
• Packaging/Storing Secretory products into secretory granules/vesicles

Question 18

Vesicular transport mechanism involves two types of coated vesicles:

_ transport products from Golgi apparatus to lysosomes or products from the exterior of the cell to the lysosomes

_ transport products between stacks of Golgi apparatus and from the ER to the Golgi apparatus

Answer 18

Clathrin-Coated Vesicles

COP-Coated Vesicles (Coat Protein)

Question 19

Clathrin-Coated Vesicles

Which pathways are they involved with?

What surrounds the neck of the invaginated coated pit, causing the neck of the vesicle to pinch off from the PM?

Answer 19

Exocytosis/Secretory and Endocytosis pathways

Dynamin

Question 20

Lysosomes

Organelle that contains 50-60 hydrolytic _ that are capable of breaking down proteins, CHO, lipids, and nucleic acids

Answer 20

Enzymes most active at acidic pH

Question 21

What do Lysosomes have that maintain acidic intralysosomal environment?

Answer 21

ATP-dependent H+ pump

Question 22

What are Primary Lysosomes? Secondary Lysosomes?

Answer 22

• Primary: Storage site of lysosomal hydrolases
  
  • No digestive events, inactive enzymes, homogenous
• Secondary: Engage in catalytic process
  
  • Digestive, active enzymes, Heterogenous

Question 23

What are 3 pathways for intracellular degradation?

Answer 23

Phagocytosis (Cell/Particle)

Autophagy (Damaged organelle)

Receptor mediated endocytosis (Macromolecules)

Question 24

How are lysosomes formed?

How do early endosomes mature into late endosomes?

What is the important change in endosome maturation?

Answer 24

Fusion of transport vesicle with endosome (contain molecules taken up by endocytosis)

Clathrin components recycled and early endosomes mature into late endosomes (precursor of secondary endosome)

Lowering of internal pH to 5.5

Question 25

Peroxisomes contain number of enzymes that form _ which is immediately broken down by _

What is its function?

Answer 25

• Hydrogen Peroxide broken down by Catalase
• Functions:
  
  • Hydrogen Peroxide Synthesis/Degradation
  • B-Oxidation of LCFAs
  • Bile Acid and Cholesterol Synthesis
  • Detoxify Alcohol

Question 26

Peroxisome biogenesis disorders that are caused by defects in the assembly of the peroxisome

Answer 26

Zellweger Spectrum disorders

Question 27

Mitochondria make up _% of the cytoplasmic volume

How can mitochondrial diseases arise?

Answer 27

20%

Mutation in the mtDNA that affect mitochondrial function or mutations in genes of nuclear DNA whose products are imported as mitochondria proteins

Question 28

Mitochondrial diseases are sometimes caused by mutations in the _ that affect mitochondrial function

Answer 28

Mitochondrial DNA