Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cell and Molecular Biology > Exam 2 > Flashcards

Exam 2 Flashcards

(94 cards)

Start Studying
1
Q

mitochondria structure

A

double membrane system:
outer membrane,
inner membrane,
intermembrane space,
matrix

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

mitochondria outer membrane

A

contains porins (channels highly permeable to small molecules and ions)

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

mitochondria inner membrane

A

cristae, many proteins for oxidative metabolism and metabolite transport

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

mitochondria matrix

A

contains mtDNA and metabolism enzymes

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

mitochondria organization

A

more mitos in high demand tissues and locations, make up dynamic tubular network (fission and fusion)

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

mitochondria fission

A

division into two units;
cell growth and division, cell polarity, eliminating bad mitos

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

mitochondria fusion

A

merging of two or more mitos inner and outer membranes;
increase energy production, buffering bad mitos, alleviating oxidative damage

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

mitochondria oxidative metabolism of ___

A

pyruvate, FAs, and AAs

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

mitochondria oxidative metabolism processes

A

TCA/CAC/Krebs,
oxidative phosphorylation

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

mitochondria TCA/CAC/Krebs

A

in matrix;
pyruvate/FAs to acetyl CoA to CO2;
NAD+ and FAD reduced to NADH and FADH2 (carry electrons)

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

mitochondria oxidative phosphorylation

A

cristae of inner membrane;
energy releasing reactions coupled to energy requiring reactions;
NADH and FADH2;
ATP synthase

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

mitochondria oxidative phosphorylation energy releasing reactions

A

electron donors to electron acceptors

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

mitochondria oxidative phosphorylation energy requiring reactions

A

ADP to ATP

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

mitochondria oxidative phosphorylation NADH and FADH2

A

NADH and FADH2 to complex I and II, to III, to IV, to O2;
exergonic (to O2);
released energy drives pumps I, III, IV to pump into intermembrane space creating potential energy as proton gradient

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

mitochondria oxidative phosphorylation NADH

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

mitochondria oxidative phosphorylation FADH2

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

TCA/CAC/Krebs metabolites

A

for growth and cell signaling;
used by mito and cytosolic proteins to form nucleotides, AAs, and FAs and cholesterol; also control gene expression by chromatin and post-translational modifications

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

mitochondria genetics

A

circular dsDNA in nucleoid, polyploid (heteroplasmy), replicate independent from cell division

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

heteroplasmy

A

two or more mtDNA variants exist in same cell

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

mitochondria post-translational protein import

A

majority of mito proteins translated by free ribosomes

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

mitochondria post-translational protein import Tom

A

outer membrane translocase;
translocate N-terminal presequence and internal sequence containing polypeptides;
send to intermembrane space

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

mitochondria post-translational protein import Tim 23

A

inner membrane translocase;
translocate N-terminal presequence containing polypeptides into matrix or inner membrane;
PAM (import motor), MPP (snips presequence), membrane potential, ATP to ADP

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

mitochondria post-translational protein import Tim 22

A

inner membrane translocase;
translocate internal sequence containing polypeptides bound to chaperones to inner membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

mitochondria post-translational protein import Tim 22 chaperones

A

Tim 9 and 10 help stabilize hydrophobic regions of polypeptides going through intermembrane space (Tom to Tim 22 or SAM) (intermembrane space is aqueous like cytosol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
mitochondria post-translational protein import Oxa 1 translocase
inner membrane translocase; for proteins translated inside mitochondria
26
mitochondria post-translational protein import Mim 1
outer membrane translocase; import α helix integral outer membrane proteins; cytoplasm to Mim 1 to laterally transported into outer membrane
27
mitochondria post-translational protein import SAM complex
outer membrane translocase; import ß-barrel integral outer membrane proteins; cytoplasm to Tom to intermembrane space to SAM complex to lateral transport into outer membrane
28
mitochondrial disease
many syndromes/age of onset/severity of diseases; inherited pathological mutations (in mom, every tissue); sporadic pathological mutations (not every tissue); onset/severity depends on level of heteroplasmy (how much mutant vs mtDNA); replacement therapy
29
peroxisome structure
single membrane; dynamic size, number, morphology, and function
30
peroxisome function
major metabolic organelles; 1) lipid synthesis 2) FA oxidation 3) ROS metabolism
31
peroxisome function lipid synthesis
lipids including plasmalogens; R1 and R2 are fatty acid tails; enriched in membranes of brain, cardiac, immune tissues
32
peroxisome function FA oxidation
in peroxisome: fatty acids activated to acyl-CoA shortened to acetyl CoA to acetyl-carnitine; transferred to mito as acetyl-carnitine; in mito: acetyl-carnitine to acetyl CoA to Krebs cycle oxidation to CO2
33
peroxisome function ROS (reactive oxygen species) metabolism
cellular metabolism increases ROS which can cause oxidative damage to macromolecules; ROS metabolizing enzymes decreases ROS levels (such as catalase and SOD)
34
peroxisome biogenesis types
de novo (brand new), division (making new from old)
35
peroxisome biogenesis de novo
ER vesicles bud with PEX transmembrane proteins; cytosolic-derived matrix proteins
36
peroxisome biogenesis de novo transmembrane proteins
V1 vesicle and V2 vesicle (diff PEX proteins) fuse to form peroxisome membrane
37
peroxisome biogenesis de novo matrix proteins
cytosol PEXs recognize peroxisome targeting sequences (on polypeptide) then mediate docking and translocation into peroxisome
38
peroxisome biogenesis division
ER vesicles bud and fuse with peroxisome to grow membrane and add more proteins; peroxisome divides
39
peroxisome disorders
diverse but often very severe, mutations in peroxisome genes (like metabolic enzymes and PEX proteins)
40
cytoskeleton
network of protein filaments plus proteins
41
actin filament structure
actin monomers (G actin) and actin filaments (F actin)
42
actin monomers
G (globular) actin; head to tail interactions
43
actin filaments
F (filamentous) actin; polymers of G actin (dimerize then trimerize then filament); distinct polarity, plus (barbed) and minus (pointed) end
44
actin filament assembly
nucleation, elongation (unbranched), and steady-state (tread milling)
45
actin filament assembly nucleation
profilin activates G actin monomers; nucleators stabilize first actin dimer and promote elongation at + end
46
actin filament assembly nucleation profilin
binds to actin and activates with ATP so it polymerizes better; ADP to ATP
47
actin filament assembly nucleation nucleators
formin dimer for unbranched, Arp2/3 for branched
48
actin filament assembly elongation (unbranched)
profilin/ATP bound actin binds at + end of formin dimer; actin acts as ATPase
49
actin filament assembly elongation (unbranched) actin as ATPase
hydrolysis (ATP to ADP) is activated when actin is incorporated into the filament, ADP-actin dissociates more readily
50
actin filament assembly steady-state/tread milling
ATP-actin joins + end at the same rate that ADP-actin leaves the - end; filament length maintenance
51
actin filament organization is maintained by
capping proteins, filament stabilizing proteins (tropomyosin), cross linking proteins
52
actin filament organization capping proteins and filament stabilizing proteins
maintain actin filament length
53
actin filament organization cross linking proteins
organize actin bundles (parallel arrays, microvilli) and actin networks (orthogonal arrays) between adjacent actin filaments
54
actin at the edge
cytoskeletal proteins and cell cortex
55
cytoskeletal proteins
link actin to plasma membrane; spectrin and ankyrin
56
cytoskeletal protein spectrin
binds actin filaments and phospholipids
57
cytoskeletal protein ankyrin
bind spectrin and transmembrane proteins
58
cell cortex
protein + membrane edge of the cell; coordinates shape, movement, interaction with other cells or environment
59
myosin structure and function
coordinates the activities of actin; prototype molecular motor; dimer; coiled coil tail groups; globular head groups contain all functional domains
60
myosin: prototype molecular motor
most myosins walk from - to + end of F actin using ATP; chemical (ATP) to mechanical (walk) energy
61
myosin: globular head groups functional domains
actin binding; ATP binding; lever arm
62
myosin II mechanism with actin: starting position
after previous round, myosin attached to actin but not bound to ATP
63
myosin II mechanism with actin: ATP
ATP binding, changes head group structure, actin dissociation/cocking of lever arm, ATP hydrolysis, ADP + Pi bound, contact with actin further toward plus end
64
myosin II mechanism with actin: power stroke
Pi released, ADP released, myosin head returns to uncocked position
65
actin-myosin in muscle contraction: myofibrils
rod-like organelles in cytoplasm of muscle fibers (cells); repeated sections of sarcomeres between two Z discs
66
actin-myosin in muscle contraction: A band
thick filaments of myosin overlapping with actin; myosin anchored at M line
67
actin-myosin in muscle contraction: I band
only thin filaments of F actin; plus end anchored to Z disc
68
actin-myosin in muscle contraction: sliding filament model
sarcomeres shorten, bringing Z discs closer; myosin orientation reverses at M line; titin springs hold myosin in place
69
actin-myosin in muscle contraction: regulation of contraction by Ca2+
nerve sends action potential, travels through T-tubules of sarcolemma, Ca2+ release from sarcoplasmic reticulum, binds to troponin bound to tropomyosin which is moved reveals myosin binding sites where myosin head can bind actin
70
actin-myosin in cytokinesis: contractile ring
constricts plasma membrane in two
71
actin-myosin in cytokinesis: regulation of contraction
Ca2+ binds calmodulin causing shape change; calmodulin binds to MLCK; MLCK activates myosin II with Pi
72
microtubule structure smallest unit
heterodimer of α and β tubulin; each encoded by small family of genes; both bind GTP in dimer form; β has GTPase activity; α stimulates β GTPase activity
73
microtubule structure polymer
made up of tubulin heterodimers; protofilaments, long strands of dimers arranged in parallel; centrosome assembles 10-15 protofilaments around hollow core and stabilizes - end; distinct polarity, - end is α, + end is β
74
microtubule assembly and disassembly
GTP dimers bind at + end; GTPase activity; dynamic instability at + end; microtubule associated proteins (MAPs)
75
microtubule assembly and disassembly: GTPase activity
when dimers polymerized hydrolysis is activated; GDP bound tubulin dissociates more readily
76
microtubule assembly and disassembly: dynamic instability
catastrophe and regrowth at the + end
77
microtubule assembly and disassembly: MAPs
microtubule associated proteins (MAPs) regulate + end stability; polymerase accelerates growth; depolymerase promotes shrinkage; CLASP stops shrinkage
78
microtubule growth
when GTP-dimer addition exceeds hydrolysis (GDP-dimer formation)
79
microtubule shrinkage (catastrophe)
when hydrolysis (GDP-dimer formation) exceeds GTP-dimer formation
80
microtubule regrowth (rescue)
when GDP-dimer leaving is stopped allowing GTP-dimer cap formation
81
microtubule organization in prototypical animal cell
microtubules grow and extend from microtubule organizing center (MTOC)
82
microtubule organizing center (MTOC) in animal cells
centrosome; pair of centrioles at center; pericentriolar material
82
MTOC in animals pair of centrioles
9 triplets of microtubules arranged in wheel structure
83
MTOC in animals pericentriolar material
matrix of proteins surrounding centrioles; γ tubulin (gamma) initiates microtubule polymerization; microtubule anchoring proteins hold - ends
84
microtubules in neuron
determine polarity; stable microtubules in axons and dendrites; ends terminate in cytoplasm (not MTOC)
85
stable microtubules in neuron
transport of cargo to the processes; retrograde transport of signals to the cell body (nucleus)
86
ends of microtubules in neuron
terminate in cytoplasm (not MTOC); capped and stabilized by MAPs (MAP1, MAP2, tau); distinct orientation in each process
87
orientation of ends of microtubules in neuron
dendrites polymerize in both directions (+ and - ends both terminate in cytoplasm); axons polymerize anterograde (- ends terminate in cytoplasm)
88
microtubular motor proteins
walk along stable microtubules; two families kinesins and dyneins; homodimers with heavy and light chains
89
microtubular motor proteins: kinesins
move toward + end; carry vesicles anterograde in cell endocytic and secretory pathways
90
microtubular motor proteins: dyneins
move toward - end; carry vesicles retrograde in cell endocytic and secretory pathways
91
microtubular motor proteins: heavy chains
ATPase activity and tubulin binding; hydrolysis changes conformation causing movement
92
microtubular motor proteins: light chains
carry cargo
93
microtubule intracellular organization and transport
microtubule - ends located near nucleus/cell interior; transport of vesicles in endocytic and secretory pathways (kinesins anterograde, dyneins retrograde); without microtubules ER would collapse and gogli unstacking

Cell and Molecular Biology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions