Cell Organelles DSA

Question 1

The liver haptocyte has a high amount of this membrane

Answer 1

mitochondria inner membrane

Question 2

the pancreatic exocrine cells has a high amount of this membrane

Answer 2

Rough ER membrane

Question 3

What are the 3 topological categories

Answer 3

!) Nucleus and cytosol (communicate through nuclear pore
complex).

2) Organelles in secretory and endocytic pathways (ER, Golgi apparatus, endosomes, and lysosomes) (communicate through vesicles).
3) Mitochondria

Question 4

what allows compartments to communicate with each other and cell exterior

Answer 4

fusion and budding

Question 5

What compartments does the ER divide the cytoplasm into?

Answer 5

1) The luminal or cisternal compartment.

2) The cytoplasmic or cytosolic compartment

Question 6

Rough ER imp functions

Answer 6

1) Proteins are modified &
Ribosomes assembled
2) Segregation of proteins for intracellular use and
3)Export from the cell (collagen, cell membrane proteins)

Question 7

how are secretory proteins directed to the ER?

Answer 7

signal sequence

Question 8

proteins that exit RER in vesicles travel to which portion of Golgi

Answer 8

cis portion

Question 9

how does the smooth ER differ from rough ER?

Answer 9

• Lacks ribosomes

- Tubular cisternae

Question 10

Functions of smooth ER

Answer 10

• Glycogen metabolism
• Lipid synthesis
• Phospholipid synthesis (other membranes)
• Detoxification
• Steroidogenesis
• Calcium regulation
• abundant in cells that make steroid or lipids

Question 11

what are functions of the Golgi complex?

Answer 11

• Modification of carbohydrates attached to glycoproteins and proteoglycans
• Polysaccharide & oligosaccharide synthesis
• Synthesis of sphingomyelin and glycosphingolipids
• Sorting secretory products
• Packaging & storing secretory products into secretory granules or vesicles

Question 12

what does the golgi complex mark lysomal enzymes with

Answer 12

mannose-6-phosphate (M6P)

Question 13

the golgi dissembles during _____ and reassembles in _____

Answer 13

mitosis/meisosi and interphase

Question 14

clathrin coated vesicles

Answer 14

transporting products from the Golgi apparatus to lysosomes or products from the exterior of the cell to lysosomes (like cholesterol)

Question 15

COP (coat protein) I coated vesicles

Answer 15

transporting products between stacks of the Golgi apparatus

Question 16

COP II coated vesicles

Answer 16

transporting products from the endoplasmic reticulum to the Golgi apparatus

Question 17

what mediates clathrin binding to vesicular membrane

Answer 17

adaptin

Question 18

in COP coated vesicles what leads to vesicle budding

Answer 18

coatomer

Question 19

In COP coated vesicles what leads to disassembly of the vesicle coat

Answer 19

hydrolysis bound GTP changes ARF to GDP-bound leading to disassembly of the vesicle coat before the vesicles fuses with a target membrane

Question 20

what causes the neck of a clatherin coated vesicle to be pinched off?

Answer 20

dynamin

Question 21

what mediates clathrin binding to vesicle membrane?

Answer 21

adaptins

Question 22

at what pH are lysosomes most active?

Answer 22

acidic pH

Question 23

what is the lysosomal sorting pathway?

Answer 23

1) synthesis of lysomal enzyme
2) phosphorylation of lysosomal enzymes (mannose 6-P (M6P)
3) inter-golgi transporting vesicles
4) binding of lysosomal enzymes to M6P receptors
5) clathrin coated transporting vesicle
6) clathrin coat is lost. M6P receptor is recycled in Golgi and lysomal enzymes soared in primary lysosome

Question 24

how to lysosomes maintain an acidic environment?

Answer 24

AtP-dependent H+ pump

Question 25

primary lysosomes

Answer 25

- the storage site of lysosomal hydrolases - No digestive events - Homogeneous - Inactive enzymes

Question 26

secondary lysosomes

Answer 26

- engaged in a catalytic process - Digestive enzymes - Heterogeneous - Active enzymes

Question 27

what are the 3 pathways for intracellular degradation

Answer 27

1) phagocytosis 2) autophagy 3) receptor mediated endocytosis

Question 28

how are lysosomes formed

Answer 28

- from the fusion of transport vesicle with endoscope | - early endoscopes mature to late endoscopes (precursors to secondary lysosomes)

Question 29

what is an imp change in endosome maturation?

Answer 29

lower of internal ph to 5.5

Question 30

Familial hypercholesterolemia

Answer 30

- Mechanism of cholesterol uptake is disrupted - Characterized by elevation of LDL, the predominant cholesterol transport protein in the plasma - Primary defect is mutation in gene encoding the LDL receptor - High levels of LDL lead to atherosclerotic plaques

Question 31

peroxisomes

Answer 31

-found in cytoplasm -contains a number of enzymes that forms hydrogen peroxide (immediately broken down by catalase) functions •synthesis and degradation of hydrogen peroxide •ß -oxidation of long-chain fatty acids •bile acid and cholesterol synthesis •detoxify alcohol

Question 32

Zellweger spectrum disorder

Answer 32

- peroxisome biogenesis disorder - defects in assembly of peroxisome - defect in any 1 of 12 genes - most serious= absent or reduced number of peroxisomes in cells - present at birth, no cure, usually death in first year of life

Question 33

which organelles originated from bacteria?

Answer 33

mitochondria and chloroplast | -adapted to generate and harness energy

Question 34

are mitochondria more or less dynamic in high energy cells?

Answer 34

less dynamic | -can pack tightly

Question 35

what is the evolution of mitochondria?

Answer 35

-fermenting bacteria to photosynthesis, to cellular respiration

Question 36

changes in mt ___ have been linked to over 200 disease states

Answer 36

tRNAs

Question 37

what does mutations of mt tRNAs prevent?

Answer 37

tRNA aminoacylation

Question 38

what are 2 types of mitochondrial disease

Answer 38

- sometimes caused by mutations in the mt DNA that affect mitochondrial function - Other causes of mt disease are mutations in the genes of the nuclear DNA, whose gene products are imported into as mt proteins as well as acquired mt conditions