Topic 9 Flashcards

(56 cards)

1
Q

porins

A

proteins that form transmembrane channels permeable to molecules below 10kDA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

cardiolipin

A

phospholipid with four fatty acyl tails synthesized within mitochondria that decrease permeability of mitochondria inner membrane to protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

cristae

A

folds of inner membrane; number varies with energy demands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

95% of human mitochondrial proteins are encoded by…

A

nuclear DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

T/F: Each mitochondria can contain diff. number of DNA molecules

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mitochondrial fission requires

A
  • dna replication
  • rna synthesis
  • membrane generation via phospholipid transfer from ER
  • protein synthesis within mitochondria and protein importation from cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most nuclear encoded mitochondrial proteins are synthesized

A

on free ribosomes in cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

import of mitochondrial matrix and inner membrane proteins

with amino terminal presequence

A

Tom, Tim, Hsp70, MPP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

target proteins to outer compartments

A

internal mitochondrial targeting sequence and internal compartment targeting sequences for intermembrane, outer, and some inner proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Tom complex

A

translocase of outer membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tim complex

A

translocase of inner membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hsp70

A

chaperones that keep proteins unfolded until reaching final destination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

MPP

A

matrix processing peptidase that cleaves targeting sequence following transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tim9, Tim10

A

inter membrane space chaperones; carry protein to Tim 22 channel complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Oxa-translocase

A

within inner membrane for proteins synthesized within matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sorting of proteins containing internal targeting sequences to inner membrane

A

Tim9,Tim10, Oxa-translocase, inner membrane protein eroded by nuclear and mitochondrial DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Sorting of proteins containing internal targeting sequences to inter membrane space and outer membrane

A

Mim1, SAM, outer membrane with alpha-helix transmembrane and beta sheet/barrel transmembrane domains, inter membrane interacting with chaperones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mim 1

A

inserts proteins with a single alpha helical transmembrane domain inserted into outer membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

SAM

A

Sorting and Assembly Machinery for moving proteins from intermembrane to outer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

cytoplasmic phospholipid transfer proteins

A

transfer phospholipids synthesized in ER to mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

catabolism

A

breakdown of large, complex molecules into smaller, simpler molecules with release of chemical energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

ATP

A

captures energy released by catabolism to form phosphoanhydride bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

hydrolysis phosphoanhydride bonds

A

provide energy for most cellular rxns

24
Q

Two sources of Acetyl CoA

A

pyruvate and fatty acids

25
pyruvate
product of glucose breakdown through glycolysis
26
Citric Acid cycle produces ___ molecules of NADH and ___ of FADH2 that are used to make ATP through _____________________ via the electron transport chain
3, 1, oxidative phosphorylation
27
reduction of NAD+
accepts a proton and 2 electrons
28
oxidation of NADH
leases a proton and 2 electrons
29
During oxidative phosphorylation, electrons that enter the electron transport chain from NADH and FADH2 combine with ___ to produce _____.
O2, H2O
30
chemiosmotic coupling
electron transport through electron transport chain is coupled to ATP synthesis
31
chemiosmotic coupling involves storage of energy in a ____________ which is subsequently used to drive ATP synthesis
proton gradient
32
5 protein complexes of electron transport chain
DNA and mitochondrial encoded proteins
33
electron carriers
negatively charged molecules that can transfer a proton
34
coenzyme Q (ubiquinone)
lipid soluble electron carrier (e- carried to complex III)
35
cytochrome c (cyt c)
peripheral membrane protein on outer face of inner membrane (e- carried to complex IV)
36
Describe transport of electrons from NADH down electron transport chain within inner membrane
- e- enter ETC from NADH in complex I - e- transferred to coenzyme Q to complex III - e- transferred from cyt b to cyt c to complex IV - complex IV transfers e- to oxygen
37
Describe transport of electrons from FADH2 down electron transport chain within inner membrane
- succinate produced in citric acid cycle is reduced by succinate dehydrogenase in complex II to generate FADH2 - FADH2 reduced to FAD +H2, donating e- to coenzyme Q - e- transported through complex III and IV driving proton pump
38
complex I and III
transfer 4 protons per pair of e- per complex
39
complex IV
transfer of 2 protons per pair of e-, plus 2 protons combined with O2 to form water
40
electrochemical gradient
pH gradient and electric potential
41
proton motive force
deltaG of ~ -5kcal/mol per proton
42
phospholipid bilayer of the inner membrane is ___________ to ions so protons can cross only through....
impermeable, protein channels
43
complex V
ATP synthase; two subunits (F0, F1)
44
F0
spans inner membrane and forms channel through which protons move
45
F1
catalyzes synthesis of ATP (contains ATP synthase)
46
The flow of protons through ___ drives the rotation of part of ____ , which acts as a rotary motor to drive ATP synthesis.
F0, F1
47
___ protons are required to synthesize 1 ATP
4
48
oxidation of one NAHD yields __ ATP and oxidation of FADH2 yields __ ATP
3, 2
49
Transport of metabolites (ATP from matrix to cytosol, inorganic phosphate and pyruvate into matrix) across the mitochondrial inner membrane relies on...
electrochemical proton gradient
50
brown adipose tissue
predominant in hibernation gland and in newborn infants; higher levels of innervation, vascularization, lipid droplets, and mitochondria
51
thermogenin
uncoupling protein of inner mitochondrial membrane in brown adipose tissue; allows for transport of protons across inner membrane into matrix without going through complex V
52
cyanide
inhibits final e- transfer to oxygen driving all e- transfer to a halt
53
mitochondrial myopathic and neuropathies
-generally affect ETC and can arise through mutations in nuclear or mitochondrial DNA
54
chloroplasts
a plastid
55
peroxisomes
-single membrane organelles of eukaryotic cells -can replicate but no genetic material carry out metabolic functions, particularly oxidation rxns -site of lipid synthesis
56
fatty acid oxidation in plants and yeast only occurs in ________ while FA oxidation in mammals also occurs in the mitochondria
peroxisomes