Cell Organelles Flashcards Preview

MCM Exam 2 > Cell Organelles > Flashcards

Flashcards in Cell Organelles Deck (24)
Loading flashcards...
1

The endoplasmic reticulum consists of what?

Cisternae

Tubules

Vesicles

2

What is the cytoplasm divided into by the ER.

The luminal or cisternae compartment

The cytoplasmic or cytoplasmic compartment

3

What types of cells have a lot of rough ER?

Cells that secrete protein.

 

(eg: Pancreatic exocrine cells v Liver Hepatocytes / 60 v 35)

4

Where does protein modification and assembly occur?

Where do these proteins go?

Rough ER

Some proteins are sorted for intracellular use and others for outside of the cell (collagen, cell membrane proteins)

5

How do ribosomes attach to the RER?

Under the guidance of the amino acid sequence, they are synthesizing. This is called the signal sequence.

6

What side of the Golgi Apparatus do proteins usually go in to?

The cis side.

7

What does the smooth ER do?

Glycogen metabolism

Lipid Synthesis

Phospholipid Synthesis

Detoxification

Steroidogenesis

Calcium regulation

8

What is the structure and purpose of the Golgi Apparatus?

Stacks of cisternae, which have a cis face facing the ER and trans face facing towards plasma membrane or nucleus

 

PTM of proteins and lipids, as well as trafficing

9

How much Nick Cage could a Nick Cage chuck if a Nick Cage could Nick Cage Nick Cage?

A Nick Cage amount of Nick Cages.

10

What does the smooth ER produce?

Polysaccharides & oligosaccharides

Sphingomyelin and glycosphingolipids

Also modifies carbs on glycoproteins and proteoglycans and provides post-translational changes.

 

 

11

What are lysosomal enzymes marked with in the Golgi apparatus?

Mannose-6-phosphate

12

In what way do materials in the Golgi Apparatus move?

Either way, retrograde or anterograde

13

What are those products moved to the lysosome from the Golgi Apparatus or membrane coated in?

What substance from the exterior is often brought to lysosomes?

Clatherin

Cholesterol

14

What do COP-coated vesicles direct themselves to?

COPII-coated vesicles?

COP I = Between Stacks and from GA to ER

COPII = From ER to GA

15

Describe endocytosis

Clathrin surrounds the receptors and adaptin to form a clatherin coated vesicle

Dynamin surrounds the neck of the coated pit, causing the vesicle to pinch off from the membrane.

16

What do lysosomes contain? How do they help the cell?

50-60 hydrolytic enzymes functional at acidic pH. 

The monomeric subunits  produced can escape into the cytoplasm through specific transporters and be reused.

17

How do primary lysosomes form?

In the GA lysosomal enzymes are phosphoralated with mannose-6-phosphate.

These bind to M6P receptor which cause the clatherin coated transport vehicle to be lost.

The enzymes are then stored in a primary lysosome

M6P receptors are returned to GA.

18

Differences in primary versus secondary lysosomes?

Primary - No digestive events, Homogenous, inactive enzymes

Secondary - Digestive enzymes, heterogeneous, active enzymes

19

What fuses to form the lysosome?

What is the hallmark of this event?

Fusion of transport vehicle and endosome

Lowering of pH to 5.5

20

What is the cause of Familial hypercholesterolmia?

Mutation in LDL receptor (incapable binding, binding at reduced capacity, incapable of internalization.)

 

Marked by elevation of LDL

Can cause atherosclerotic plaques

21

What is the function of peroxisomes?

synthesis and degradation of hydrogen peroxide

ß -oxidation of long-chain fatty acids

bile acid and cholesterol synthesis

detoxify alcohol
 

22

What are peroxisome disorders known as?

Zellweger spectrum disorders

The worst of which is Zellweger syndrome which is the absence or reduced number of peroxisomes in cells. Usually death within the first year of life.

23

How do high energy cells pack mitochondria versus others?

Much more packed, such as between myofibrils in high energy cells.

24

What causes the mitochondrial DNA diseases?

Mutations in the mt DNA that affect function (sometimes)

Also caused by mutations in the nuclear DNA which products may be imported into the mitochondria.