Cell Phys Exam 3 (Module 9-13)

0.0(0)
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/132

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

133 Terms

1
New cards

functions of mitochondria

ATP production, cell death, calcium homeostasis, amino & fatty acid metabolism, aging, immunity

2
New cards

beta oxidation

fatty acid metabolism

3
New cards

mitochondrial matrix

contains mitochondrial genome, ribosomes, and metabolic enzymes

4
New cards

positive charge of MTS is attracted to negative charge of matrix

why must the matrix be negatively charged?

5
New cards

mitochondrial inner membrane

contains electron transport chain

6
New cards

mitochondrial outer membrane

contains channels that transport proteins from cytosol into mitochondria

7
New cards

endosymbiosis

mitochondria were an ancient bacterium that was engulfed by an ancient primitive archaeal cell

8
New cards

proteome

the complete set of proteins that make up a specific organelle

9
New cards

1%

what percentage of total mitochondrial proteins is encoded by the genome?

10
New cards

99%

percentage of mitochondrial proteins encoded by nucleus

11
New cards

mitochondrial genome

encodes for some of the subunits of the electron transport chain

12
New cards

F, it only codes for SOME, the rest come from the nucleus

T/F: The mitochondrial genome encodes for all of the subunits of the electron transport chain.

13
New cards

T

T/F: Proteins have sorting signals to target them to specific cell locations

14
New cards

signal sequences

can be found at the edge or within proteins; very specific due to having specific arrangements & compositions of amino acids that are recognized by specific proteins to bring them to the organelle

15
New cards

after the entire genome is translated

when do mitochondrial proteins enter the mitochondria?

16
New cards

cytosolic ribosomes

responsible for post-translational translocation

17
New cards

free cytosolic & ER-bound

what types of ribosomes translate proteins?

18
New cards

Green Fluorescent Protein

fluorophore that glows in the presence of blue light; used to find localization signals on proteins; attaching targeting sequence will bring it to where that protein is going to

19
New cards

aequorin

bioluminescent protein that gives off blue light

20
New cards
  1. specific mitochondrial targeting sequences

  2. specific transporters

what does mitochondrial protein import involve?

21
New cards

mitochondrial matrix targeting sequence

Located at N-terminus of matrix protein; amphipathic helix; must be at beginning of protein sequence; only cleavable

22
New cards

mitochondrial inner membrane sequence

has non-cleavable transmembrane segment & cleavable targeting sequence

23
New cards

T

T/F: It is possible to have only non-cleavable internal sorting sequences in a protein

24
New cards

mitochondrial outer membrane sequence

has non-cleavable internal sorting sequences

25
New cards

TOM (Translocase of the Outer Membrane) complex

recognizes all nuclear encoded mitochondrial proteins through multiple receptors; only recognizes targeting sequence of outer membrane proteins; located in outer mitochondrial membrane; INDIRECTLY inserts protein into outer membrane

26
New cards

SAM complex

DIRECTLY inserts nucl. encoded mitochondrial proteins into outer membrane through mediation of the TOM complex

27
New cards

TIM22 (translocase of the inner membrane) complex

inserts nucl. encoded mitochondrial proteins into inner membrane

28
New cards

TIM23 complex

dimer; the transporter that brings proteins into the matrix and the inner mitochondrial membrane

29
New cards

OXA complex

inserts mito encoded mitochondrial proteins into inner membrane

30
New cards

mitochondrial targeting sequence

MUST be the first amino acid sequence in the protein

31
New cards

TOM40

central channel that proteins pass through

32
New cards

TOM20 & TOM22

the receptors recognizing matrix proteins with a MTS (mitrochondrial targeting sequence)

33
New cards

TOM20

recognizes hydrophobic side

34
New cards

TOM22

recognizes positively charged side

35
New cards

TIM50

first receptor to bind incoming matrix protein as it passes thru TOM40

36
New cards

until the stop-transfer sequence is recognized

when an inner membrane protein reaches the TIM channel, it will travel thru until when?

37
New cards

cytosolic hsp70

makes sure protein is linear1

38
New cards

mitoHSP70

chaperone that binds incoming MTS of matrix protein and pulls it in

39
New cards

peptidase

what cleaves MTS?

40
New cards

mitochondrial and nuclear genomes

encode mitochondrial inner membrane proteins

41
New cards

2

there must be how many import pathways for inner membrane proteins?

42
New cards

Path A

import pathway for nuclear encoded mito inner membrane proteins

43
New cards

nuclear encoded mito inner membrane proteins

have MTS & a hydrophobic stop-transfer sequence

44
New cards

Path B

import pathway for mitochondrial-encoded mito inner membrane proteins

45
New cards

through genome and ribosomes

how do mitochondria translate ETC subunit proteins?

46
New cards

OXA1 complex

transports mitochondrial-encoded proteins into inner membrane

47
New cards

OXA1 targeting sequence

contained in mitochondrial-encoded mito inner membrane proteins and found in genome-encoded proteins

48
New cards

T

T/F: All outer membrane proteins come from nuclear genome

49
New cards

F

T/F: TOM complex directly inserts the protein into the outer membrane

50
New cards

T

T/F: SAM complex directly inserts an outer membrane protein into the outer membrane

51
New cards

nucleus

largest organelle; contains chromatin (DNA)

52
New cards

nuclear envelope

double membrane (outer & inner); selective transport of molecules in & out of nucleus; contains nuclear pores

53
New cards

nuclear pores

used to transport molecules between nucleus & cytoplasm

54
New cards

nuclear lamina

on the inner side of the inner membrane; support structure

55
New cards

nucleolus

major site of ribosome biogenesis

56
New cards

nuclear envelope outer membrane

contiguous (merged) w/ ER

57
New cards

passive diffusion

Process by which molecules move across a cell membrane from an area of higher concentration to an area of lower concentration without the use of energy

58
New cards

active diffusion

molecules move across membrane from high to low concentration using ATP

59
New cards

passive

proteins smaller than 40 kDa can move in & out of the nuclear pore via ___ diffusion

60
New cards

active

larger proteins move in & out of the nuclear pore via ___ diffusion

61
New cards

terminal structures

extend on either end of nuclear pore

62
New cards

docking

attachment of proteins to the nuclear pore; energy independent

63
New cards

transport thru nuclear pore

requires energy, is selective & requires regulation

64
New cards

nuclear localization sequence

dictates nuclear import; sorting sequence that targets proteins to nucleus

65
New cards

basic residues of NLS

Arginines/R & Lysines/K

66
New cards

necessary

proteins would only go to cytoplasm & not nucleus without NLS

67
New cards

sufficient

NLS can drive localization to the nucleus by putting it w/ GFP

68
New cards

importins

recognize NLS (localization)

69
New cards

exportins

recognize NES (export)

70
New cards

GTPases

control whether a protein is imported or exported

71
New cards

guanine nucleotide exchange factor (GEF)

exchange GDP for GTP

72
New cards

T

T/F: every protein w/ a NES inherent has an analyze sequence because an analyze sequence is required for import

73
New cards

ran GTPase

GTP bound in nucleus

74
New cards

ran GTPase during import

allows release of cargo from importin in nucleus

75
New cards

ran GTPase during export

binding needed for exportin to bind NES-containing cargo proteins

76
New cards

ran GAP

causes ran GTPase to hydrolyze GTP to GDP which releases cargo; located in cytoplasm

77
New cards

key to ran GTPase regulation

location of ran GAP and GEF

78
New cards

ran GEF

in nucleus; needed to have an active ran GTPase to release cargo from importin and to bind export cargo

79
New cards

Ntf2

used to get ran GDP back into the nucleus after GTP hydrolysis

80
New cards

dual-localized protein

function can be same or different in each cellular compartment

81
New cards

mitochondrial unfolded protein response (UPRmt)

protein has both MTS and NLS; transcriptional GEP reporter is used to study activity & experimented in worms

82
New cards

nucleus

all mitochondrial chaperones & proteases are expressed in the ___

83
New cards

ATFS-1

transcription factor that regulates genes that repair mitochondria; during mitochondrial stress it increases expression of chaperones & proteases; has a nuclear export sequence

84
New cards

import into matrix requirements

ATP hydrolysis & membrane potential

85
New cards

TIM9 & TIM10

chaperones that assist w/ insertion of outer membrane proteins into the outer membrane

86
New cards

F: it is only for ran-GDP

T/F: Ntf2 goes back to the cytoplasm for repeated nuclear import of Ran-GTP

87
New cards

weaker membrane potential, less ATP & less mitochondrial import

why does the electron transport chain not work for stressed mitochondria?

88
New cards

F: healthy mitochondria can fuse to unhealthy ones to help out

T/F: mitochondria cannot fuse together

89
New cards

F: ATFS-1 will be degraded because it’s no longer needed

T/F: Healthy mitochondria will import ATFS-1 and store it for later use

90
New cards

F: there is a possibility not to express it when stressed

T/F: A worm will not express fluorescent green only when not stressed

91
New cards

cytoskeleton functions

  • Cell support and shape

  • Cell motility

  • Cell polarity

  • Cell engulfment

  • Cell migration      

  • Wound healing

92
New cards

T

T/F: Cytoskeletal components are all protein polymers

93
New cards

characteristics of actin

  • ubiquitous

  • highly conserved

  • abundant

  • multiple isoforms

  • polarized

  • has longitudinal & lateral bonds to strengthen filament

94
New cards

G-actin

units that make up F-actin

95
New cards

plus end of actin filament

where monomers are put on

96
New cards

minus end of actin filament

where subunits fall off

97
New cards

actin monomer

composed of 2 lobes & a cleft; is an ATPase

98
New cards

T

T/F: ATP hydrolysis is not required for polymerization of the actin filament, but instead is used to regulate the filament

99
New cards

3 phases of actin polymerization

nucleation, elongation & steady state

100
New cards

rapid

is actin elongation slow or rapid?