Exam #1: Cell Biology V

Question 1

COPI

Answer 1

• Coating-Protein I
• Golgi (Trans)–>ER
• Retrograde

Question 2

COPII

Answer 2

• Coating Protein II
• ER–> Golgi (Cis)
• Anterograde

Question 3

Clathrin

Answer 3

• Plasma membrane into the cell

- Trans Golgi–> out of the cell

Question 4

SNAREs

Answer 4

Mediate vesicular transport by recognizing one another

Question 5

t-SNARE

Answer 5

• Target SNARE

- Allows the vesicle to recognize its target domain

Question 6

v-SNARE

Answer 6

• Vesicular SNARE

- E.g. synaptotagmin & Synaptophysin

Question 7

What is the function of retrograde transport?

Answer 7

• Maintain membrane balance
• Transport of SNARE proteins back to ER
• Correction of Mis-sorting/ Delivery

Question 8

What is the role of SNARE proteins in neurotransmission?

Answer 8

• Secretory vesicle recognition

- Release of NT

Question 9

Botulinum Toxin

Answer 9

• Eliminates t-SNARE (proteolysis)
• Prevents neurotransmission/ NT release
• Causes paralysis of muscle

Question 10

What are the two organelles that have two plasma membranes?

Answer 10

• Mitochondrion

- Nucleus

Question 11

Cristae

Answer 11

• Foldings of the mitochondrion

- Contain ATP Synthase & enzymes of oxidative phosphorylation

Question 12

What can you tell about a mitochondrion that has a large number of cristae vs. a cell that has few cristae?

Answer 12

More cristae= produces more ATP/ has a higher ATP need

Question 13

What cell type has no mitochondria?

Answer 13

RBC

Question 14

Mitochondrial Matrix

Answer 14

• Space that the cristae project into
• Contains matrix granules
• Contains mitochondrial DNA
• TCA cycle enzymes
• Beta-oxidation enzymes

Question 15

Outer Mitochondrial Membrane

Answer 15

More permeable

Question 16

Inner Mitochondrial Membrane

Answer 16

• Less permeable
• Control the hydrogen ion gradient
• Electron transport, ATP synthase…etc. contained here
• CO & cyanide poisoning

Question 17

What two organelles are involved in the synthesis of steroid hormones?

Answer 17

• Mitochondrion

- sER

Question 18

What five complexes are involved in the transport of proteins into the mitochondria?

Answer 18

• TOM
• TIM 22
• TIM 23
• SAM
• OXA

Question 19

What confers acidophilic striations at the light microscope level?

Answer 19

• Mitochondria in palisades (picket-fence)

- Very abundant mitochondria involved in hydrogen ion transport

Question 20

Tubular Cristae

Answer 20

Hallmark features of mitochondria that are associated with steroid hormone synthesis

• Testis, ovaries, adrenal cortex
• Closely associated with lipid droplets containing cholesterol

Question 21

How is the synthesis of steroid hormones described?

Answer 21

Ping-pong process

Question 22

MERRF

Answer 22

• Myoclonic Epilepsy with Ragged Red Fibers
• Mitochondrial Disorder
• Light microscope= red mitochondira w/ Gomori Trichrome Stain
• EM= “parking lot” inclusion
• Symptoms include involuntary jerking/ twitching, seizures, & gait disturbances
• Maternally inherited

Question 23

Myoclonus

Answer 23

• Hiccups

- Sleep Jerk

Question 24

What happens to the shape of the mitochondria in response to alcoholic cirrhosis?

Answer 24

Odd-shaped in response to injury

Question 25

What are the functions of the peroxisome?

Answer 25

1) Beta-oxidation of FFAs 2) Plasmalogen Synthesis 3) Regulate Hydrogen Peroxide 4) Kill Pathogens 5) Oxidize Ethanol

Question 26

Plasmalogens

Answer 26

- Abundant type of phospholipid found in myelin | - Very important for development

Question 27

Zellweger Syndrome

Answer 27

- Disease state caused by defective import of peroxisomal enzymes

Question 28

Thin Filaments

Answer 28

- Actin | -

Question 29

Intermediate Filaments

Answer 29

- Very diverse class of cytoskeletal elements

Question 30

Thick Filaments

Answer 30

- Myosin

Question 31

Microtubule

Answer 31

- Hollow structure - Made of tubulin dimers that polymerize - Can exist independently in the cytoplasm - May assemble into doublets

Question 32

Dynein

Answer 32

- ATPase associated with microtubules - Allows microtubules to be motile and become cilia & flagella - Also microtubule motor that transports material from the positive end to the negative end

Question 33

What are the functions of microtubules?

Answer 33

1) Support the cytoplasm 2) Organelle Support 3) Cell division 4) Motility of cilia & flagella 5) Long-range transport of vesicles

Question 34

Kinesin

Answer 34

- Microtubule motor - Transports from negative end (nucleus) to positive end - E.g. neurotransmitters