Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Foundations of Medicine > FOM Week 1 > Flashcards

FOM Week 1 Flashcards

1
Q

What is the purpose of the cytoskeleton?

A

Structural strength, transport, movement and directional info

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

What does it mean when a cytoskeleton is dynamic?

A

location and life cycle can alter the protein output and ratios

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

At what end does actin tend to have subunits added to?

A

The plus end, but can have units added to the minus end

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

What important molecule does actin have a binding site for?

A

ATP binds right in the center

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

What are ARPs? What do they do?

A

ARPs for a complex and bind to the minus end of the actin filament, stabilizing it. Filament will then grow rapidly on plus end. They also bind other acting molecules at a 70 degree angle and create a meshwork

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

How do microtubules compare to actin?

A

They are thicker and consist of heterodimers of alpha and beta tubulin subunits 13 protofilaments come together

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

What are the locations of the plus and minus end of a microtubule?

A

Plus end lies in the periphery and the minus end is in the centriole

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

What is the purpose and outcome of the GTP cap on microtubules?

A

GTP cap stabilizes microtubule allowing for growth

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

What happens to a microtubule with a GDP cap?

A

a GDP cap is unstable, the microtubule will begin to shrink GDP encourages curving of the protofilament which can lead to shrinking

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

What can be used to stabilize the minus end of a microtubule?

A

Gamma tubulin

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

What is formin?

A

Dimer that allows actin to grow faster by stabilizing the plus end and adding subunits

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

What is profilin?

A

binds actin to enhance ATP binding and adds actin subunits to the plus end

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

What is cofilin?

A

binds actin and condenses it leading to a shorter and thicker filaments

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

What is a subunit example of a microfilament?

A

actin

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

What are a few subunit examples intermediate filaments?

A

Vimentin (mesenchyme) Glial fibrillary acidic proteins (glia) Neurofilament (neurons) Keratins (epithelia) Nuclear lamin Desmin (muscle)

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

What is a subunit example of microtubules?

A

alpha and beta tubulin

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

What are the common structural properties of fibrillar proteins?

A

Repeating globular subunits and long twisting fibers Building structures for cytoskeleton or ECM Actin tubulin - repeating alpha and beta subunits creating protofilaments

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

What are the common structural properties of integral membrane proteins? What are examples?

A

Surrounded by hydrophobic lipid membrane Inside out distribution of amino acids - hydrophobic amino acids span the membrane and hydrophilic sit outside the membrane Bundles of alpha helicies and beta barrels

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

What are the common structural properties of intrinsically disordered proteins?

A
  1. Not globular 2. Unpredictable secondary structure 3. No hydrophobic core 4. Long repetitive sequences 5. Appear to fold when binding targets 6. Bind wide range of targets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain the characteristics of proteins with similar sequences

A

These are homologs Can have as little as 25% of same seq but have similar function Difference in residues lead to individual characteristics

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

What are the functional classes that proteins can share?

A

Chemical Signaling structure transport storage

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

Provide an example of an isoform and explain what it is.

A

Hexokinase (phosphorylates many sugars) vs glucokinase (phosphorylates just glucose) Isoforms have same general function but subtle differences

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

Can proteins share a common ligand? If so explain.

A

Yes Many proteins can bind ATP and have similar binding sites for this to occur

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

What are two common post-translational modifications?

A

Phosphorylation and proteolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is phosphorylation

A

Protein kinase removes a hydroxyl and the addition of a phosphate group. Can activate or deactivate a protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the characteristics of proteolysis?

A

Proteases cleave the phosphate backbone Create a new N and C terminus Irreversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a characteristic of protein modularity?

A

Mix and match of different classes on one polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a domain?

A

A domain is a part of a polypeptide that may have its own specific function Each domain may have its own characteristics and the function of the whole may not be knocked out by deletion of one domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the types of folding?

A

On purpose or accidential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is an example of a protein unfolding on purpose?

A

Protein digestion in the stomach as well as lysosomal protein degradation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What can happen what a protein is accidentally misfolded?

A

It can be targeted for degradation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is cytoplasmic crowding and what can be a result of it?

A

The cytoplasm is very crowded and proteins can push up against each other possibly leading to protein unfolding. This can expose hydrophilic sidechains that will glomb to other side chains and aggregate together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What factors can cause a protein to denature?

A

pH, Ionic strength, Pressure, Temp, Urea, Osmotic Pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a pathological result of protein unfolding?

A

Amyloid formation can occur when unregulated protein aggregation occurs from different native folding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What factors can enhance folding?

A

Osmolytes, chaperone proteins, and chaperonins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is an osmolyte and what are some examples of osmolytes?

A

Component that affects osmosis Amino acids, polyols (glycerol), methylamines (TMAO), Covalent osmolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is an example of a chaperone protein and what do they do?

A

Heat shock proteins Aid in folding new proteins, help in misfolded proteins and transport across a membrane These bind to smaller sections and aid in folding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the characteristic and functions associated with chaperonin proteins?

A

Much larget than HSPs barrel structure provides inner cavity for protein folding Cytosolic protein Lid shuts on the proteins Proteins can go through chaperonins multiple until desired folding is achieved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the major degredative pathways in a cell?

A

Lysosomes and Proteosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the characteristics of a lysosome?

A

Low pH to unfold protein and acid proteases to degrade the proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the characteristics of a proteosome?

A

Large cytosolic protein and utilizes ubiquitin tagging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How can degradation play a part in a role such as cystic fibrosis?

A

Mutation leads to slower protein folding, and thus the protein is degraded before it can fold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What intermediate filament is characteristic of muscle

A

Desmin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What intermediate filament is characteristic of epithelia?

A

Keratins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What intermediate filament is characteristic of neurons?

A

Neurofilaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What intermediate filament is characteristic of glia?

A

Glial fibrillary acidic protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What intermediate filament is characteristic of mesenchyme?

A

Vimentin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What proteins act to stabilize actin bundles?

A

Fimbrin - tight, doesnt allow myosin to connect creates parallel bundles Spectrin Actinin - allows for myosin creating contractile bundles Filamin dimers- creates and stabilizes actin meshwork

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Why do so few actinopathies exist? Why do the genetic codes of all actin proteins seem to be so closely related?

A

Actin is extremely important and most embryos with actin mutations rarely make it past the 16 cell stage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What protein can stabilize the minus end of a microtubule?

A

Gamma tubulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What two microtubule associated proteins play important roles in neurons?

A

MAP2 and Tau proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Describe the characteristics of a MAP2 protein?

A

Binds adjacent microtubules and allows for correct spacing of microtubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the tole of Tau proteins?

A

These bind microtubules and pack them in tighter bundles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is a Tau tangle and how can it form?

A

Tau tangles occur when the Tau proteins hyperphosphorylate and begin to create amyloids. They are no longer in contact with the MT. This has been linked to CTE and brain injuries

55
Q

What are the characteristics of epidermis bullosa simplex?

A

Mutations of keratin 5 and 14 are weak Disruption of basal layer Critical condition leads to infant death

56
Q

What are the characteristics of epidermolytic hyperkeratosis?

A

Mutation of Keratin 1 and 10 Basal layer unaffected, epidermis affected cause damage to joints

57
Q

What are the characteristics of epidermolytic plantopalmar keratoderma?

A

Mutation of keratin 9 Disruption of epidermis that is restricted to palms and soles

58
Q

All glands are what?

A

EPITHELIAL!!!

59
Q

What are the functions of the epithelium

A

Absorption, secretion, transport, excretion, protection, and sensory reception

60
Q

What are the features of the epithelium?

A

Connected to each other tightly Lie on a basement membrane Form membranes and glands Have a distinct polarity Line all body surfaces, cavities and tubes

61
Q

What are the three polarities an epithelial cell can have?

A

Apical (towards the top) Lateral (Sides) Basal (bottom)

62
Q

What are the characteristics of the apical domain?

A

Microvilli, Cilia, and stereocilia

63
Q

What are characteristics of microvilli and how do we distinguish them?

A

Microvilli are short projections of the luminal membrane This leads to greatly increased surface area These specialized for absorption Actin core Appear as a brushed border on histology slides

64
Q

What are the characteristics of cilia?

A

These have a microtubule core Specialize in motility Inserted into the basal bodies Movement is driven by ATP

65
Q

What are main difference between cilia and microvilli

A

Cilia - microtubule core and aid in movement Microvilli - actin core and aid in absorption

66
Q

What are a few key characteristics of Kartengers Syndrome?

A

It is a PCD Patients experience situs inversus Possibly caused by the dyenin arms missing from microtubules

67
Q

What are the characteristics of stereocilia?

A

Very long microvilli Contain long filamentous actin core Facilitates absorption Found in male epididymis

68
Q

What are the characteristics of the Basal Domain?

A

Basal Lamina/Basement membrane Hemidesmosomes Basal infoldings

69
Q

What are the characteristics and features of the basal lamina?

A

ECM proteins act as an interface between epithelium and supporting tissues Aid in establishing polarity and growth of the epithelial cells Contains the lamina lucidia and lamina densa

70
Q

What is contained within the basement membrane

A

Lamina Reticularis

71
Q

What are the characteristics of hemidesmosomes?

A

Link to epithelial cells in the basal lamina Cell to ECM interactions Link to intermediate filament proteins inside the cell

72
Q

What is an integrin?

A

Transmembrane hemidesmosome linker protein

73
Q

What is bullous phemphigoid

A

Auto-immune disease that attacks BP230 and BP180 (hemidesmosomes) A blistering disease that results from the splitting of the epithelium from the basal lamina

74
Q

What are basal infoldings?

A

High concentrations of mitochondria allow for enhanced cellular traffic

75
Q

What are the parts of the lateral domain?

A

Zonula occludens, Zonula adherens, Desmosomes, and gap junctions

76
Q

What are the characteristics of the zonula occludens?

A

Block passage of luminal contents between cells Acts as a collar on the apical side of the cell Tight junction proteins made of claudin form sealing strands

77
Q

What are the characteristics of the zonula adherens?

A

Adherens junction Lateral adhesions between epithelial cells Through the actin cytoskeleton Where the cell membrane interacts with the actin

78
Q

What are the characteristics of desmosomes?

A

Cadherins and adhesion proteins - join intermediate filament in one cell to another Thought to be a spot weld Meant to withstand a large amount of friction

79
Q

What is pemphigus?

A

Cells lose contact and blisters are formed Involving cadherins Leading to suprabasal blistering

80
Q

What are gap junctions?

A

Lateral junctions comprised of two connexons that allow material to pass though

81
Q

What are the characteristics of glands?

A

They are epithelial cells that have undergone proliferation, migration, and differentiation Specialized to produce fluid secretion Intracellular synthesis of macromolecules Secretory products stored in secretory granules

82
Q

What are characteristics of unicellular glands?

A

Small dense core of secretory granules Nucleus at the basal section of the cell Synthesize and secrete hormones Intestine and respiratory system involvement (ex goblet cells)

83
Q

What are the types of signaling?

A

Autocrine, paracrine, endocrine

84
Q

What is autocrine signaling?

A

self stimulation “cellular masturbation”

85
Q

What is paracrine signaling

A

Signals sent to a nearby protein

86
Q

What is endocrine signaling?

A

Signals sent to the bloodstream for distant targets

87
Q

What are the methods of signaling?

A

Merocrine, apocrine, and holocrine

88
Q

What is merocrine signaling?

A

Conversion of membrane - exocytosis

89
Q

What is apocrine signaling?

A

Secretion includes apical portion of the cell

90
Q

What is holocrine signaling?

A

Involved total loss of the cell

91
Q

What are the types of secretion from glands?

A

Serous - Enzymatic Mucous - mucins

92
Q

What are current diagnostic limitations DNA sequencing?

A

Price, Time, cannot predict efforts of all proteins

93
Q

What is fimbrin?

A

tight, doesnt allow myosin to connect creates parallel bundles

94
Q

What is actinin?

A

allows for myosin creating contractile bundles

95
Q

What is filamin?

A

dimers that create and stabilizes actin meshwork sit on top

96
Q

What connect actin filaments in tight bundles, doesnt allow myosin to connect creates parallel bundles

A

fimbrin

97
Q

What connects actin filaments and allows for myosin to connect creating contractile bundles

A

actinin

98
Q

What is a dimers that creates and stabilizes actin meshwork sit on top?

A

filamin

99
Q

Dimer that allows actin to grow faster by stabilizing the plus end and adding subunits looks like a collar

A

formin

100
Q

binds actin to enhance ATP binding and adds actin subunits to the plus end looks like swinging arms

A

profilin

101
Q

binds actin and condenses it leading to a shorter and thicker filaments

A

cofilin

102
Q

What is the primary structure of a protein and what are its implications and what are the main interacting forces in it?

A

The primary structure is the amino acid sequence, this sequence has a preferred 3D structure and this determines the function of the enzyme. It utilizes peptide bonds that exhibit a partial double bond characteristic

103
Q

What makes up the secondary structure of proteins and what forces are at work?

A

In secondary structure the appearance of alpha helicies and beta sheets begins to happen. This local folding occurs that is stabilized by H-bonding between N-H and C=O groups

104
Q

What is the tertiary structure of a protein and what are the intramolecular forces that drive it?

A

Tertiary structure is the 3 dimensional structure of a protein with incorporation of side chain interactions. Disulfide bridges can form. Hydrophonic interactions cause hydrophobic residues to aggregate to the center of the protein away from the aqueous environment. Ionic bonds, H-bonds, and van Der waals forces are also at work.

105
Q

What is quartnerary structure of a protein and how is this differenct then aggregation? What is a homodimer and what is a heterodimer?

A

Quarternary structure is when a functional protein consists of multiple peptide chains, whereas aggregation is the unregulated grouping of unrelated proteins.

Homodimer- 2 of the same polypeptide chains interacting

Heterodimer- 2 different polypeptide chains interacting

106
Q

How can proteins be in motion?

A

In small proteins side chains can rotate and be flexible.

Larger proteins tend to have hinges that allow them to bend and flex

107
Q

A mutation in this protein leads to Marfan’s syndrome

A

What is fibrillin-1?

Fibrillin-1 forms fibrils in the ECM leading to abnormalities in connective tissue

108
Q

What is a homolog?

A

Proteins that carry a similar sequence

109
Q

What side chains in a protein can be phosphorylated?

A

Serine, tyrosine, or threonine

110
Q

Proteins that are unable to be degraded by the the person are what?

A

These are allergens, they keep their from even after exposure to the various organs of the body

111
Q

How many aggregated proteins are needed to form an amyloid?

A

Amyloids consist of at least 21 proteins aggregated together

112
Q

What specific proteins make up amyloids and what are they resistant to?

A

Trick question: Amyloid protein formation is non-specific. Proteins of different types aggregate together and form extremely stable protein structures. Their stability is demonstrated because they are resistant to proteolysis and autoclave resistant.

113
Q

What are examples of osmolytes?

A

Amino acids-proline, alanine, and taurine

114
Q

What are the roles of heat shock proteins?

A

Fold new proteins

Refold misfolded proteins

Transport across a membrane

Control activities of some proteins

115
Q

Why is SDS-PAGE beneficial for integral membrane proteins?

A

Integral membrane proteins won’t work well (or maybe not at all) on native gel electrophoresis (which separates on protein charge, not size), because they are not soluble. The SDS of SDS-PAGE can solubilize the unfolded forms of integral membrane proteins.

116
Q

What is the G-actin protein and what is its process?

A

The G-actin protein is an actin subunit. It has a plus and minus end and will bind to ATP. When the subunit is attached to the actin filament, the ATP will be hydrolyzed to ADP.

117
Q

What is a key feature associated with intermediate filaments?

A

These will form head to tail coiled dimers

118
Q

What is epidermolysis bullosa and what causes it?

A

In the skin the predominant intermediate filament is keratin. This keratin is linked to the hemidesmosome, which links the cytoskeleton to the ECM. In this disease the keratin is weakened, but the hemidesmosome is strong. Mechanical stress will cause cells to rupture along the basal edge, leaving some of the cell attached to the basal lamina. It is caused by a mutation in keratin 5 and 14 and pts develope blisters shortly after birth

119
Q

What is epidermolytic hyperkeratosis?

A

A mutation in keratin 1 and 10, and these are found in the middle of the epidermis. These cells will separate, but the separation will cause the basal cell layer to stimulate the division of basal cells to produce more tissue, thus the term hyperkeratosis.

120
Q

What is epidermolytic plantopalmar keratodema?

A

A mutation of in keratin 9 gene that damages tissues on the palms of the hands and the soles of the feet. Keratinized skins slough off easier.

121
Q

Fill in this chart

A
122
Q

What is the ARP complex and what does it do?

A

Activation of ARP2 and 3 will form a complex that binds to the minus end of actin, stabilizing it and allowing for the rapid growth of actin. Once bound to the actin it can attach to other existing actin molecules at a 70 degree angle, thus forming an actin meshwork.

123
Q

What is formin and how does it relate to cytoskeletal development?

A

Formin is a dimer that stabilizes the actin bundle making it tighter hugging. It shimmies its way up the actin filament.

124
Q

What is profilin?

A

The profilin has actin monomers bound to it. Essentially this protein complex will bind actin and then stick it onto the plus end of the actin filament. This allows the very rapid elongation of the actin filament.

125
Q

What is cofilin?

A

Cofilin is another protein that cells use to modify the actin filament. If cofilin binds to the actin filament the actin filament will rotate in a smaller distance. The distance from one helix to the next is reduced in the presence of cofilin.

126
Q

What are alpha-actinin and fimbrin and what are the differences between the two?

A

Alpha-actinin is a protein that creates contractile bundles. This has enough space for mysosin II to bind. If the actin filaments are bundled by fimbrin, then there is not enough space for the myosin to bind. This is a way for the cell to control actin myosin interactions.

127
Q

What is filamin and how is it different from ARP?

A

Filamin is a protein that forms a dimer, and helps to stabilize the actin meshwork. This will provide extra strength to the cell. This is when the actin filaments weave over eachother not joining side by side actin filaments.

128
Q

What are the functions of the MAP2 and Tau proteins?

A

MAP2 will bind to adjacent microtubules and allow a greater distance between microtubules. The binding of tau allows the microtubules to be packed into a tighter bundle.

129
Q

What are the features of microvilli?

A

They have a core of actin filaments that insert into the terminal web. They increase the surface area of the apical membrane. They are specialized in absorption

130
Q

Hemidesmosomes link the what to the what?

A

Link the intermediate filament proteins inside the cell to the extracellular matrix proteins of the basal lamina

131
Q

What disease is most likely the cause of this and how does it occur?

A

Bullous phemphigoid. Auto-antibodies to the BP antigens cause the splitting of the epithelium from the basal lamina. The individual keratinocytes remain attached to each other, but the epithelium splits from the basal lamina

132
Q

What is phemphigus?

A

autoantibodies for a type of cadherin (desmoglein) protein attack. This causes suprabasal blistering as basal cells remain attached to basal lamina.

133
Q

What are the 3 methods of secretion?

A
134
Q
A

Foundations of Medicine (79 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions