Organelle DSA

Question 1

Golgi Apparatus

1. Structure
2. Function

Answer 1

1. Stacks of dislike compartments

2. Post translational changes in proteins and lipids, Trafficking

Question 2

Mitochondria

1. Structure
2. Function

Answer 2

1. Have outer and inner matrix

2. Make ATP, signaling, cell differentiation, and cell death

Question 3

Lysosomes

1. Structure
2. Function

Answer 3

1. Contain digestive enzymes

2. Degrade organelles and biomolecules

Question 4

Peroxisome

1. Structure
2. Function

Answer 4

1. Small vesicular compartment that contains enzymes

2. Oxidation reactions

Question 5

Three topological categories

Answer 5

1. Nucleus and cytosol—communicate through nuclear pore)
2. ER, Golgi, endosome, lysosome—involved in secretory pathways and communicate through vesicles.
3. Mitochondria

Question 6

Cell that make secreted proteins have many…..

Answer 6

RER! (Ribosomes on the endoplasmic reticulum.

Question 7

Rough Endoplasmic Reticulum

1. Structure
2. Function

Answer 7

1. Parallel sacks of flat elongated cisternae studded with ribosomes
2. Protein modification and assembly, segregation of proteins for internal and external use, export from the cell.

Question 8

Smooth Endoplasmic Reticulum

1. Structure
2. Function

Answer 8

1. Contiguous with RER, but lacks ribosomes and has tubular cisternae.
2. Glycogen metabolism, lipid synthesis, phospholipid synthesis, detox, steroidogenesis, calcium regulation

Question 9

SER is abundant in cells that do what?

Answer 9

Make steroids or lipids

Question 10

Golgi apparatus has two ends…

Answer 10

Entry—CIS, is adjacent to the endoplasmic reticulum.

Exit—TRANS, faces the plasma membrane or the nucleus

Question 11

These types of vesicles transport products from the Golgi apparatus to the lysosome or from the exterior of the cell to the lysosome. The end game here is to get stuff to the lysosome.

Answer 11

Clathrin-coated vesicles

Question 12

This type of vesicle transports products between stacks of the Golgi.

Answer 12

COPI-coated vesicles (COat Protein)

Question 13

This type of vesicle transports products from the endoplasmic reticulum to the Golgi

Answer 13

COPII-coated vesicles

Question 14

Clathrin is used in two pathways

Answer 14

1. Exocytosis/SECRETORY

2. Endocytosis (to the lysosome)

Question 15

What protein is used to “pinch” the vesicle from the membrane

Answer 15

Dynamin

Question 16

What protein allows clathrin to bind to the vesicle membrane?

Answer 16

Adaptin.

Clathrin does not bind directly to the membrane.

Clathrin binds to adaptin which binds to receptor molecules which have bound to cargo on the outside of the cell that need to be brought in.

Question 17

How do lysosomes maintain an acidic enviornment?

Answer 17

ATP-depended H+ pump

Question 18

There are two different kinds of lysosomes. What are they and what is the difference?

Answer 18

1. Primary lysosomes—storage site of lysosomal hydrolases. There are NO digestive enzymes, the contents are HOMOGENOUS, and the enzymes are INACTIVE. (Think about them like they have been freshly made and have not been used yet.)
2. Secondary lysosomes are engaged in a catalytic process. They have ACTIVE DIGESTIVE enzymes and have HETEROGENEOUS contents.

Question 19

What are the 3 pathways for intracellular degradation?

Answer 19

1. Phagocytosis—large particles, such as another cell, are brought into the cell; “eaten”
2. Autophagy—cell components are degraded within the same cell.
3. Receptor mediated endocytosis—larger molecules are brought into the cell via receptors.

Question 20

When are lysosomes formed?

Answer 20

Lysosomes are formed via
Fusion of transport vesicle with endosome.

Early endosomes mature into late endosomes which are precursors to secondary endosomes.

Key step in endosome maturation»>lowering of internal pH to 5.5

Question 21

Is clathrin digested in the lysosome after it has brought molecules into the cell?

Answer 21

No, clathrin is recycled back to the cell membrane.

Question 22

Familiar Hypercholesterolemia

1. Disfunction
2. Possible consequences of Disfunction
3. Clinical marker

Answer 22

1. Mutation in gene that encodes the LDL receptor.
2. • receptor is unable to bind LDL
   • receptor binds at reduced capacity
   • receptor binds normally, but is incapable of internalization.
3. Characterized by elevation of LDL which can lead to atherosclerotic plaques

Question 23

Functions of Peroxisomes (also called Microbodies)

Answer 23

• synthesize and degrade hydrogen peroxide.
• beta-oxidation of long-chain fatty aids
• synthesize bile acid and cholesterol
• detoxifies alcohol

Question 24

Zellweger Spectrum Disorder

Answer 24

Peroxisome assembly disorder

12 genes involved with the proper assembly of peroxisomes—a mutation in any one can cause disorders of the zellweger spectrum

Most serious=Zellweger syndrome—absence or reduced number of peroxisomes in the cell.

Congenital, no cure, death within first year of life.

Question 25

What organelle evolved from bacteria

Answer 25

Mitochondria <3

They even evolved to retain their own DNA

Question 26

Mitochondria make up ____% of the cytoplasmic volume and are often associated with ________.

Answer 26

20% of the cytoplasmic volume

Associated with microtubular cytoskeleton

Question 27

In high energy cells, mitochondria are…

Answer 27

More fixed, less dynamic.

Can pack tightly between myofibrils and around flagellum of sperm cells.

Question 28

Mitochondrial DNA diseases are caused by….

Answer 28

1. Mutations in the mitochondrial DNA that affect the mitochondrial function
2. Mutations of the nuclear DNA whose gene products are imported as mitochondrial proteins.