Mitochondria

Question 1

Label

Answer 1

Question 2

Define cristae:

Answer 2

folds in the inner membrane of the mitochondria that allow for maximal surface area for reactions

Question 3

Cristae are studded with ______including ATP synthase and cytochromes

Answer 3

proteins

Question 4

______have prismatic cristae (for closer packing)

Answer 4

Astrocytes

Question 5

Mitochondrial _______ and _______ typically counterbalance each other. Levels of nutrients and other criteria can tip the balance toward either or.

Answer 5

fusion, division

Question 6

Mitochondria are moved around the cell on _______

Answer 6

microtubules

Question 7

In ion-transporting cells, many mitochondria are often located _______

Answer 7

near basolateral cell membrane infoldings and provide locally needed ATP

Question 8

The electron transport chain takes place on the ____________.

Answer 8

inner mitochondrial membrane

Question 9

Oxidative metabolism of nutrients creates a ________ in the ETC.

Answer 9

proton gradient

Aerobic respiration requires

Oxygen in order to generate ATP. Pyruvate enters the mitochondrion in order to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP, by substrate level phosphorylation, NADH and FADH2.

Question 10

Which complexes pump protons?

Answer 10

Complex I, III, and IV

Question 11

Proton gradient is utilized to generate ______.

Answer 11

ATP

Question 12

Label

Answer 12

Question 13

Once protons are in the intermembrane space, they use a _________ to flow back into the matrix

Answer 13

stationary F₀ channel

Question 14

ATP synthase which rotates as it generates ATP from ADP

Answer 14

F₁

Question 15

From F₁ ATP exits using ________

Answer 15

VDAC (voltage-dependent anion channel). Pyruvate (nutrients) also enter the cell using VDAC.

Question 16

Unique phospholipid of the inner mitochondrial membrane that helps ATP transporter line up to face VDAC

Answer 16

Cardiolipin

Question 17

Proteins have a matrix-targeting sequence (series of AA’s) that is recognized by _________ and ________.

Answer 17

TOM (transport outer membrane), TIM (transport inner membrane)

Question 18

Imports cholesterol into mitochondria so it can undergo the first step in steroid synthesis

Answer 18

STAR Protein

Question 19

Steroid cells have mitochondria with _______shaped cristae.

Answer 19

tubular

Question 20

Maintains intracellular Ca²⁺homeostasis by transporting Ca²⁺ from the cell cytosol into the mitochondrial matrix.

Important for shaping Ca²⁺ signals and the activation of programmed cell death.

Answer 20

MCU (Mitochondria Calcium Uniporter)

Question 21

Matrix granules are rich in ______.

Answer 21

calcium

Question 22

Mitochondria have their own ______, ______, and ______ and even synthesize some of their own proteins

Answer 22

DNA, RNA, ribosomes

Question 23

Mitochondria have [more/fewer] tRNAs than are used by the rest of the cell and follow relaxed pairing rules.

Answer 23

fewer

The genetic code also differs from that found in the rest of the cell.

Question 24

Mitochondrial genes evolve more rapidly than nuclear genes.

Mitochondrial genes are inherited by a non-Mendelian mechanism known as ___________ from mother.

Answer 24

“cytoplasmic inheritance”

Question 25

Mitochondrial numbers within a cell vary depending upon ______ and ______.

Answer 25

energy production, energy needs

Question 26

When intracellular ATP becomes depleted, cells respond by:

Answer 26

• Metabolizing glycogen
• Increasing glucose uptake
• Increasing mitochondrial number and activity to produce more ATP

Question 27

AMP-Activated Protein Kinase (AMPK) activated by:

Answer 27

• Increase in the AMP/ATP ratio
• Starvation (fuel deficiency)
• Increased phosphocreatine

AMPK function as a fuel senor for the cell

Question 28

Activated AMPK alters the ________________and the

Answer 28

function of many proteins, transcription of many genes

Question 29

Regulate the transcription of many mitochondrial genes

Answer 29

NRF-1 and NRF-2

Question 30

Define apoptosis

Answer 30

Programmed cell death

Question 31

Intrinsic apoptosis pathway:

Answer 31

• Cell damage or stress
• Permeability transition pore in the inner mitochondrial membrane opens
• Proton gradient dissipation
• Swelling of the mitochondrion
• Release of several apoptotic factors into the cytoplasm

Question 32

Apoptotic factors released into the cytoplasm:

Answer 32

• Cytochrome C
• Apoptosis-inducing factor (AIF)
• Procaspases

Question 33

Cytochrome c causes activation of the _____________________ by which other caspases are activated

Answer 33

caspase proteolytic cascade

Question 34

A caspase is a

Answer 34

proteolytic enzyme

Question 35

Cytochrome c activation results in _________ and leads to _________

Answer 35

massive protein degradation; destruction of the nuclear lumins

Question 36

Apoptosis-inducing factor (AIF) is translocated to the nucleus and ______________

Answer 36

induces destruction of the chromatin.

Question 37

Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig Disease) is characterized by __________

Answer 37

death of motor neurons of the spinal cord.

It is associated with mitochondrial damage in neurons.

Relatively rare (2/100,000 in population)

Question 38

Inherited form of ALS involves a misfolded enzyme __________ that may block VDAC

Answer 38

superoxide dismutase (SOD)

Question 39

The flow of H+ ions cause a portion of _______ to rotate and simultaneously generate ATP

Answer 39

ATP synthase

Question 40

AMPK Increase the Transcription of ___________

Answer 40

Nuclear Respiratory Factor NRF-1 mRNA

Question 41

AMPK is Required for _________in response to starvation in muscle

Answer 41

mitochondrial biogenesis