Brainscape's Knowledge GenomeTM

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


See full index

Chapter 1 pathology > chapter > Flashcards

chapter Flashcards

1
Q

architectural planning

A

noncoding regions

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

what are thefive major classes of functional non–protein- coding sequences in the human genome

A

1.Promoter and enhancer
2.Noncoding regulatory RNAs
3.telemeres and centromeres
4.Mobile genetic elements/transposons
5.chromatin structures

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

percentage of human genome that does not encode proteins

A

dark matter, 1.5%

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

Noncoding regulatory RNAs

A

micro-RNAs (miRNAs) and long noncoding RNAs (lncRNAs)

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

A major component of centromeres

A

satellite DNA

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

The two most common forms of DNA variation in the human genome are

A

single nucleotide polymorphisms (SNPs) and copy number variations (CNVs)

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

are variants at single nucleotide positions and are almost always biallelic

A

SNPs

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

Heterochromatin

A

dense, inactive

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

Euchromatin

A

disperse and active

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

are repetitive nucleotide sequences that cap the termini of chromatids and permit repeated chromosomal replication without deterioration of genes near the ends.

A

telomeres

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

can be visualized only during mitosis

A

Chromosomes

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

act as the locus for the formation of a kinetochore protein complex that regulates chromosome segregation at metaphase

A

centromeres

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

are noncoding regions of DNA that initiate gene transcription; they are on the same strand and upstream of their associated gene

A

Promoters

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

can modulate gene expression over distances of 100 kb or more by looping back onto promoters and recruiting additional factors that drive the expression of pre–messenger RNA (mRNA) species

A

Enhancers

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

may be useful markers if they
happen to be coinherited with a disease-associated polymorphism as a result of physical proximity

A

SNPs

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

are a form of genetic variation consisting of different numbers of large contiguous stretches of DNA

A

CNVs

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

heritable changes in gene expression that are not caused by variations in DNA sequence

A

epigenetics

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

T/F
alterations in DNA sequence cannot by themselves explain the diversity of phenotypes in human populations

A

True.
e.g. classic genetic inheritance cannot explain differing phenotypes in monozygotic twins

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

differentiated cells have distinct structures and functions that arise as a result of lineage- specific gene expression programs. Such cell type–specific differences in transcription and translation depend on

A

epigenetic factors

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

_______consist of DNA segments 147 bp long that are wrapped around a central core structure of highly conserved low molecular weight proteins called ________

A

nucleosome, histone

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

T/F
only the regions that are “unwound” are available for transcription

A

True

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

T/F

Histones are static

A

False. Histones are not static, but rather are highly dynamic

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

covalent alterations

A

methylation, acetylation, or phosphorylation

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

carry out over 70 different histone modifications generically denoted as “marks.”

A

Chromatin writer” complexes

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

what are your covalent modifications

A

Histone methylation
Histone acetylation
Histone phosphorylation
DNA methylation
Chromatin organizing factors

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

lysines and arginines modified

A

Histone methylation

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

whose modifications tend to open the chromatin and increase transcription. In turn, these changes can be reversed by histone deacetylases (HDACs), leading to chromatin condensation

A

Histone acetylation

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

Serine residues can be modified by

A

Histone phosphorylation

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

modification that typically results in transcriptional silencing

A

DNA methylation

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

believed to bind to noncoding regions and control long-range looping of DNA

A

Chromatin organizing factors

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

T/F
Unlike genetic changes, many epigenetic alterations (e.g., histone acetylation and DNA methylation) are reversible and amenable to therapeutic intervention

A

True

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

These genomic sequences are transcribed but not translated.

A

Micro-RNA and Long Noncoding RNA

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

do not encode proteins; they modulate translation of target messenger RNAs (mRNAs)

A

miRNAs

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

Generation of microRNAs (miRNAs) and their mode of action in regulating gene function.

A

miRNA transcribed-> pri-miRNA-> pre-miRNA-> mature double-stranded RNA

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

cleave or repress translation of mRNA, resulting in posttranscriptiontional silencing.

A

RISC

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

mechanisms used by lncRNAs modulate gene expression

A

gene activation
gene supression
promote chromatin modification
assembly of protein complexes

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

is transcribed from the X chromosome and plays an essential role in the physiologic X chromosome inactivation

A

XIST
-XIST itself escapes X inactivation but forms a repressive “cloak” on the X chromosome from which it is transcribed, resulting in gene silencing.

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

These are linked genetic elements that endow prokaryotes with a form of acquired immunity to phages and plasmids

used for gene editing

makes it possible to selectively edit mutations that cause hereditable disease, or—perhaps more worrisome—to just eliminate less “desirable” traits.

A

1) clustered regularly interspaced short palindromic repeats (CRISPRs)
2) Cas9 nuclease.

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

CELLULAR HOUSEKEEPING Involves

A

a. Plasma Membrane: Protection and Nutrient Acquisition
b. cytoskeleon
c. cell-cell interaction
d. ER and Golgi apparatus

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

normal housekeeping functions of the cell are compartmentalized within membrane bound intracellular organelles because?

A

a. potentially injurious degradative enzymes or toxic metabolites can be kept at usefully high concentrations without risking damage to more delicate intracellular constituents
b. maintain low pH and high calcium intracellular environment
c. maintain polarity

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

New proteins destined for the plasma membrane or secretion are physically assembled in

A

RER and Golgi

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

proteins intended for the cytosol are synthesized on

A

free ribosome

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

is used for steroid hormone and lipoprotein synthesis and modification of hydrophobic compounds into water-soluble molecules for export.

A

Smooth endoplasmic reticulum (SER)

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

are “disposal” complexes that degrade denatured or otherwise “tagged” cytosolic proteins

A

Proteasomes

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

They are the site of senescent intracellular organelle breakdown (a process called autophagy) and where phagocytosed microbes are killed and catabolized.

A

Lysosomes

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

contain catalase, peroxidase, and other oxida-
tive enzymes

generate hydrogen peroxide

A

Peroxisomes

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

Movement—of both organelles and proteins within the cell, as well as the entire cell in its environment—is accomplished by

A

cytoskeleton

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

cytoskeleton is composed of

A

a. filamentous actin (microfilaments)
b. keratins (intermediate filaments)
c. microtubules

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

are essential to generation and maintenance of cell polarity

A

cytoskeleton

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

Loss of polarity could lead to?

A

disrupt vectorial transcellular transport in the intestine or renal tubule

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

😤sites of synthesis of heme
😀generate atp
🥹contain important sensors of cell damage to initiate apoptosis
😝last only 10 days
🫣from maternal side

A

mitochondria

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

😜fluid bilayers of amphipathic phospholipid
😓have hydrophobic lipid tails that interact with each other
😚remarkably heterogeneous

A

Plasma membrane

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

🔫inner membrane leaflet
🔫serve as electrostatic scaffold

A

Phosphatidylinositol

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

can be hydrolyzed by phospholipase C to generate intracellular second signals like diacylglycerol and inositol trisphosphate.

A

polyphosphoinositides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

normally restricted to the inner face where it confers a negative charge

when flippedit becomes a potent “eat me” signal during programmed cell death (e.g., apoptosis)

cofactor in blood clotting

A

Phosphatidylserine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

located on the extracellular face of plasma membrane

contribute to including inflammatory cell recruitment and sperm-egg fusion.

A

Glycolipids and sphingomyelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

The plasma membrane is liberally studded with a variety of proteins and glycoproteins involved in

A

(1) ion and metabolite transport
(2) fluid-phase and receptor- mediated uptake of macromolecules
(3) cell-ligand, cell-matrix, and cell-cell interactions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

In general, proteins associate with the lipid bilayer by one of four mechanisms.

A
  1. integral or transmembrane proteins
  2. synthesized on free ribosomes
  3. Proteins anchored by glycosylphosphatidylinositol (GPI)
  4. Peripheral membrane protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Many plasma membrane proteins function as large complexes; these may be aggregated either under the control of

A
  1. chaperone molecules in the RER
  2. lateral diffusion in the plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Membrane Transport

A

Passive Diffusion
Carriers and Channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Small, nonpolar molecules like O2 and CO2 readily dissolve in lipid bilayers and therefore rapidly diffuse across them. they transport through

A

Passive Diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

effective barrier to the passage of larger polar molecules (>75 Da); at 180 Da, for example, glucose is effectively excluded.are also impermeant to ions due to their charge and hydration.

A

Plasma membrane/lipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

in tissues responsible for significant water movement (e.g., renal tubular epithelium), thes special integral membrane proteins serves as transmembrane channels

A

aquaporins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

These transporters that move ions, sugars, nucleotides, etc., frequently have exquisite specificities, and can be either active or passive. For example, some transporters accommodate glucose but reject galactose.

A

Carriers and Channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

create hydrophilic pores, which, when open, permit rapid movement of solutes (usually restricted by size and charge)

A

Channel proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

bind their specific solute and undergo a series of conformational changes to transfer the ligand across the membrane; their transport is relatively slow.

A

Carrier proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

are used when concentration gradients can drive the solute movement; activation of the channel opens a hydrophilic pore that allows size-restricted and charge-restricted flow.

A

Channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

are required when solute is moved against a concentration gradient; this typically requires energy expenditure to drive a conformational change in the carrier that facilitates the transmembrane delivery of specific molecules.

A

Carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

T/F
active transport of certain solutes (against a concentration gradient) is accomplished by carrier molecules (NEVER channels) at the expense of ATP hydrolysis or a coupled ion gradient.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Endocytosis of receptor-ligand pairs often involves

A

clathrin-coated pits and vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

involves membrane invagination to engulf large particles and is most common in specialized phagocytes (e.g., macrophages and neutrophils)

A

Phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

can mediate transcellular transport in either apical-to-basal or basal-to-apical directions, depending on the receptor and ligand.

A

Transcytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

causes net movement of water out of cells
extracellular salt in excess of that in the cytoplasm

A

hypertonicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

may be denoted pinocytosis (“cellular drinking”) or phago- cytosis (“cellular eating”)

A

endocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

T/F
Generally, phagocytosis is restricted to certain cell types (e.g., macrophages andneutrophils) whose role is to specifically ingest invading organisms or dead cell fragments.

A

True

76
Q

proteins that spontane- ously assemble into a basket-like lattice which helps drive endocytosis

A

clathrin

77
Q

In this process, proteins synthesized and packaged within the RER and Golgi apparatus are concentrated in secretory vesicles, which then fuse with the plasma membrane to
EXPEL their contents

A

exocytosis

78
Q

is the movement of endocytosed vesicles between the apical and basolateral compartments of cells

A

Transcytosis

79
Q

two types of endocytosis

A

Caveolae-mediated endocytosis
Receptor-mediated endocytosis

80
Q

are noncoated plasma membrane invaginations associated with GPI-linked molecules

A

Caveolae

81
Q

is the major structural protein of caveolae, which, like membrane raft

enriched in glycosphingolipids and cholesterol

A

caveolin

82
Q

Internal- ization of caveolae along with bound molecules and associated extracellular fluid is called

cellular sipping

A

potocytosis

83
Q

Receptor-mediated endocytosis.

A

clathrin-coated pits

84
Q

The vesicles then rapidly lose their clathrin coating and fuse with an acidic intracellular structure called the

A

early endosome

85
Q

Defects in receptor-mediated transport of LDL underlie

A

familial hypercholesterolemia

86
Q

gives the cell its ability of cells to adopt a particular shape, maintain polarity, organize intracellular organelles, and migrate depends on an intracellular scaffold of structural proteins

A

Cytoskeleton

87
Q

three major classes of cytoskeletal proteins

A
  1. Actin microfilamentsare 5- to 9-nm diameter fibrils
  2. Intermediate filaments are 10-nm diameter fibrils
  3. Microtubules are 25-nm-thick
88
Q

use G-actin

abundant cytosolic protein in cells

control cell shape and movement

responsible for other functions that depend on actin contraction including vesicular transport, epithelial barrier regulation, and cell migration.

A

Actin microfilaments and myosin

89
Q

form ropelike polymers and do not usually actively reorganize like actin and microtubules

tensile strength

bear mechanical stress

link desmosomes and hemidesmosomes

A

intermediate filament

90
Q

characteristic tissue-specific patterns of intermediate filament

A

Vimentin-mesenchymal cells
Desmin-muscle cells
Neurofilaments-neuronal axon
Glial fibrillary acidic protein- glial cells
Cytokeratins- epithelial cells
Lamins-nuclear lamina, define nuclear shape

91
Q

composed of nonco-
valently polymerized α- and β-tubulin dimers organized into hollow tubes

Serve as mooring lines for molecular motor proteins that use ATP to translocate vesicles

Mediate sister chromatid segregation

Form the core of primary cilia

A

Microtubules

note: mutations in the proteins of the primary cilia complex lead to forms of polycystic kidney disease

92
Q

two varieties of these motor proteins of microtubules

A

kinesins and dyneins

93
Q

motor protein actin microfilament

A

myosin

94
Q

3 types of cell-cell jun tions

A

Occluding junctions (tight junctions)
Anchoring junctions (adherens junctions and desmosomes)
Communicating junctions (gap junctions)

95
Q

seal adjacent epithelial cells together

restricts the paracellular (between cells) movement of ions

boundary that separates apical and baso- lateral membrane domain to maintain polarity

A

Occluding junctions (tight junctions)

96
Q

mechanically attach cells—and their cytoskeletons—to other cells or the ECM

are formed by homotypic extracellular interactions between transmembrane glycoproteins called CADHERINS, on adjacent cells

A

Anchoring junctions

97
Q

are often closely associated with and beneath tight junctions

associated with intracellular actin microfilaments

A

adherens junctions

note: lost of E-cadherin explains the discohesive invasion pattern of some gastric cancers and lobular carcinomas of the breast

98
Q

cadherins are linked to intracellular INTERMEDIATE filaments, allowing extracellular forces to be mechanically communicated

A

desmosomes

99
Q

the transmembrane connector proteins are called integrins

attach to intermediate filaments

endothelium in the bloodstream or cardiac myocytes in a failing heart

A

hemidesmosomes

100
Q

permit the diffusion of chemical or electrical signals from one cell to another.

critical role in cell-cell communication

cardiac myocytes allow cell-to-cell calcium fluxes

A

Communicating junctions (gap junctions)

101
Q

is the site for synthesis of all transmembrane proteins and lipids for plasma membrane and cellular organelles, including the ER itself.

the initial site of synthesis for secreted proteins.

A

endoplasmic reticulum (ER)

102
Q

assist in folding and retaining proteins in the ER until the modifications are complete and the proper conforma- tion is achieved.

A

Chaperone molecules

103
Q

a codon deletion leads to the absence of a single amino acid (Phe508) which results in its misfolding, ER retention and catabolism and therefore reduced surface expression.

A

CFTR protein in cystic fibrosis

104
Q

From the RER, proteins and lipids destined for other organelles or extracellular export are shuttled into the ?

A

Golgi apparatus

105
Q

Golgi can be recognized as a ___________ on simple hematoxylin and eosin stains

A

perinuclear hoff

106
Q

the ____ is relatively sparse and primarily exists as the transition zone

be particularly conspicuous in cells that synthesize steroid hormones

A

SER

note: In muscle cells, specialized SER called sarcoplasmic reticulum is responsible for the cyclic release and sequestration of CALCIUM ions that regulate muscle contraction and relaxation

107
Q

responsible for catabolism of long-chained fatty acids.

A

peroxisomes

108
Q

include proteases, nucleases, lipases, glycosidases, phosphatases, and sulfatase

containing
roughly 40 different acid hydrolases

A

Lysosomes

109
Q

three pathways of lysisomes

A
  1. fluid-phase or receptor-mediated endocytosis
  2. autophagy
  3. Phagocytosis
110
Q

play an important role in degrading cytosolic proteins

A

Proteasomes

111
Q

evolved from ancestral prokaryotes

contain their own DNA

are encoded by both nuclear and mitochondrial DNA

X-linked, autosomal, or maternally inherited

constantly undergoing fission and fusion

undergoes mitophagy

regulating apoptosis

A

Mitochondria

112
Q

mitochondrial functions

A

Energy generation

intermediate metabolism

cell death

113
Q

parts of mitochondria

A

Inner membrane- core matrix space that harbors the bulk of the enzymes of the glycolytic and tricarboxylic acid cycles

Outside the inner membrane/intermembrane space- site of nucleotide phosphorylation

114
Q

summry of oxidatvie metabolism

A

mitochondria oxidize substrates to CO2, transferring the high-energy electrons from the original molecule (e.g., sugar) to molecular oxygen. Oxidation of various metabolites drives proton pumps that transfer H+ from the core matrix into the intermembrane space. As the H+ ions flow down their electrochemical gradient and out of the intermembrane space, the energy released is used to generate ATP.

115
Q

the brown fat that allows rapid substrate oxidation without ATP synthesis that allows tissues with high levels of UCP-1 to generate heat (nonshivering thermogenesis)

A

thermogenin

116
Q

increase uptake of glucose and glutamine and switch to aerobic glycolysis, a phe- nomenon called the_____. each glucose molecule is catabolized to lactic acid (even in the presence of adequate oxygen), generating only two net ATP molecules but “spinning off” intermediates

A

Warburg effect

117
Q

External cellular injury (toxin, ischemia, trauma) can damage mitochondria, inducing the formation of

A

mitochondrial permeability transition pores in the outer membrane, making atp generation impossible.

118
Q

integrate intracellular proapoptotic and antiapoptotic effector signals to generate a final “go” or “no go” signal for apoptosis.

A

Mitochondria
this happens when permeability transition happens and release cytochrome C into the cytoplasm

119
Q

The signals that most cells respond to can be classified into several groups. these are

A

Danger and pathogens
Cell-cell contacts
Cell-ECM contacts
Secreted molecules.

120
Q

Signaling pathways based on the spatial relationships

A

Paracrine signaling-
Autocrine signaling-cell affect itself
Synaptic signaling-transmitters
Endocrine signaling-mediator released to the bloodstream

121
Q

signal that is conveyed is transmitted to the cell via these specific receptor protein

A

Intracellular receptors
Cell-surface receptors

122
Q

are generally transmembrane proteins with extracellular domains that bind activating ligands.

A

Cell-surface receptors

123
Q

Depending on the receptor, ligand binding can cell surface receptors can:

A

-Open ion channels
-Activate an associated GTP-binding regulatory protein
(G protein).
-Activate an endogenous or associated enzyme
-Trigger a proteolytic event

124
Q

associated receptors are typically involved in signaling that drives cellular proliferation; proteolytic or conformation changes are common features of multiple pathways (e.g., Notch, Wnt, and Hedgehog)

A

G protein–coupled receptors and tyrosine kinase– associated receptors

125
Q

The interaction of a cell-surface receptor and its ligand can activate signaling through

A

1.ligand-induced clustering of the receptor (receptor cross-linking)
2. inducing a physical change in receptor structure

note: Either mechanism results in a conformational change in the cytosolic tail of the receptor

126
Q

Signal Transduction Pathways

A
  1. Receptors associated with kinase activity
  2. G-protein coupled receptors (GPCRs)
  3. Nuclear receptors
  4. (Receptor proteins of the Notch family, Wnt protein ligands,Frizzled family receptors)
127
Q

Modular Signaling Proteins, Hubs, and Nodes

A

• Enzyme activation (or inactivation).
• Nuclear (or cytoplasmic) localization of transcription
factors (see later).
• Transcription factor activation (or inactivation).
• Actin polymerization (or depolymerization).
• Protein degradation (or stabilization).
• Activation of feedback inhibitory (or stimulatory) loops.

128
Q

play a key role in organizing intracellular signaling pathways

A

Adaptor proteins

129
Q

T/F
Most signal transduction pathways ultimately induce durable effects on cellular function by modulating gene transcription; this occurs through the activation and/or nuclear localization of transcription factors

A

True

130
Q

large multiprotein enzymatic complex that is responsible for RNA synthesis.

A

RNA polymerase

131
Q

stimulate the activity of signaling pathways and genes that augment cell survival, growth, and division.

A

Growth factors

132
Q

Growth factors bind to specific receptors and, ultimately, influence expression of genes that:

A

• Promote entry into the cell cycle.
• Relieve blocks on cell cycle progression (thus promoting
replication).
• Prevent apoptosis.
• Enhance synthesis of components (nucleic acids, proteins,
lipids, carbohydrates) required for cell division.

133
Q

sources::Activated macrophages, salivary glands, keratinocytes, many other cells

function: Mitogenic for many cell types; stimulates epithelial cell migration; stimulates formation of granulation tissue

A

Epidermal growth factor (EGF)

134
Q

Mesenchymal cells

Stimulates proliferation of endothelial cells; increases vascular permeability

A

Vascular endothelial growth factor (VEGF)

135
Q

Activated macrophages, keratinocytes, many other cells

Stimulates proliferation of hepatocytes and many other epithelial cells

A

Transforming growth factor-α (TGF-α)

136
Q

Fibroblasts, stromal cells in the liver, endothelial cells

Enhances proliferation of hepatocytes and other epithelial cells; increases cell motility

A

Hepatocyte growth factor (HGF) (scatter factor)

137
Q

Platelets, macrophages, endothelial cells, smooth muscle cells, keratinocytes

Chemotactic for neutrophils, macrophages, fibroblasts, and smooth muscle cells; activates and stimulates proliferation of fibroblasts, endothelial cells, and other cells; stimulates ECM protein synthesis

A

Platelet-derived growth factor (PDGF)

138
Q

Macrophages, mast cells, endothelial cells, many other cell types

Chemotactic and mitogenic for fibroblasts; stimulates angiogenesis and ECM protein synthesis

A

Fibroblast growth factors (FGFs) including acidic (FGF-1) and basic (FGF-2)

139
Q

Platelets, T lymphocytes, macrophages, endothelial cells, epithelial cells, smooth muscle cells, fibroblasts

Chemotactic for leukocytes and fibroblasts; stimulates ECM protein synthesis; suppresses acute inflammation

A

Transforming growth factor-β (TGF-β)

140
Q

Fibroblasts

Stimulates keratinocyte migration, proliferation, and differentiation

A

Keratinocyte growth factor (KGF)

141
Q

by virtue of their proliferative effects, gain-of-function mutations convert them into onco- genes that lead to unfettered cell division and can be precur- sors to malignancy

A

proto-oncogenes

142
Q

recepter that is overexpressed in a subset of breast cancers.

A

ERB-B2 receptor

143
Q

has mitogenic effects on hepatocytes and most epithelium including biliary, lung, kidney, breast, and skin.

A

Hepatocyte Growth Factor (HGF).

144
Q

acts as a morphogen in embryonic development

A

HGF

145
Q

is frequently overexpressed or mutated in tumors, particu- larly renal and thyroid papillary carcinomas.

A

MET

146
Q

is the major angiogenic factor after injury and tumors

A

VEGF-A

147
Q

are involved in embryonic vessel development

A

VEGF-B and PlGF

148
Q

stimulate both angiogenesis and lymphatic development (lymphangiogenesis).

A

VEGF-C and VEGF-D

149
Q

is the most important inducer of VEGF production

A

hypoxia

150
Q

is highly expressed in endothelium and is the most important for angiogenesis

A

VEGFR-2

151
Q

increased levels of soluble VEGFR-1 (also known as s-FLT-1) in pregnant women may cause

A

preeclampsia (hypertension and proteinuria)

152
Q

has the most widespread distribution and is commonly referred to simply as TGF-β

A

TGF-β1

153
Q

TGF-β signaling has multiple—and often opposing—effects, depending on the tissue type and any concurrent signals. Agents with such multiplicity of effects are called

A

pleiotropic

154
Q

stimulates the production of collagen, fibronectin, and proteoglycans and inhibits collagen degradation

for scar formation

drives fibrosis in lung, liver, intestines, and kidneys

inhibiting lymphocyte proliferation and activity of other leukocytes

A

TGF-β

155
Q

ECM functions as a

A
  1. Mechanical support
  2. Regulator of cell proliferation
  3. Scaffolding for tissue renewal
  4. Foundation for establishment of tissue microenvironments
156
Q

The ECM occurs in two basic forms:

A

interstitial matrix and basement membrane

157
Q

occupies the spaces
between stromal cells within connective tissue and between parenchymal epithelium and the underlying supportive vascular and smooth muscle structures in some organs.

A

Interstitial matrix.

158
Q

what are found in your BASEMENT MEMBRANE

A

• Type IV collagen
• Laminin
• Proteoglycan

159
Q

what is in the INTERSTITIAL MATRIX

A

• Fibrillar collagens
• Elastin
• Proteoglycan and hyaluronan

160
Q

Components of the Extracellular Matrix

A
  1. Fibrous structural proteins (collagens and elastin)
  2. Water-hydrated gels (proteoglycans and hyaluronan)
  3. Adhesive glycoproteins
161
Q

types of collagen

A
  1. Fibrillar collagens (type 1,2,3,5)
  2. Nonfibrillar collagens (type 4)
162
Q

Genetic defects, including collagen and lysyl hydroxylase mutations, cause diseases such as

A

osteogenesis imperfecta and certain forms of Ehlers-Danlos syndrome

note: lysyl hydroxylase, is dependent on vitamin C, explaining why children with ascorbate deficiency have skeletal deformities and why individuals of any age with vitamin C deficiency heal poorly and bleed easily.

163
Q

The ability of tissues to elastically recoil and return to a baseline structure after physical stress is conferred by

important in cardiac valves and large blood vessels, which need to accommodate recurrent pulsatile flow, as well as in the uterus, skin, and ligaments.

A

elastin

164
Q

confer resistance to compressive forces; in joint cartilage, proteo- glycans also provide a layer of lubrication between adjacent bony surfaces

A

Proteoglycans and Hyaluronan

165
Q

The sequence of events that results in cell proliferation is called the cell cycle; it consists of

A

G1 (gap 1), S (DNA synthesis), G2 (gap 2), and M (mitotic) phases; quiescent cells that are not actively cycling are in the G0 (gap 0) state

166
Q

a major constituent of basement membrane

A

laminin

167
Q

a major constituent of basement membrane

A

laminin

168
Q

a major component of the interstitial ECM

A

fibronectin

169
Q

Cell cycle progression is chaperoned by proteins called

A

cyclin

170
Q

the checkpoint that monitors DNA integrity before irreversibly committing cellular resources to DNA replication.

A

G1-S

171
Q

the restriction point insures that there has been accurate genetic replication before the cell actually divides.

A

G2-M

172
Q

If the genetic derangement is too severe to be repaired, cells either undergo apoptosis or enter a nonreplicative state called

A

senescence

173
Q

Enforcing the cell cycle checkpoints is the job of

A

CDK inhibitors (CDKIs)

174
Q

have the dual property of being able to self renew and to give rise to differentiated cells and tissues.

A

Stem cells

175
Q

cells that can give rise to the full range of differentiated tissues

A

totipotent

176
Q

only have the capacity to replace damaged cells and maintain cell populations within the tissues where they reside.

A

adult stem cells

177
Q

Under conditions of homeostasis, stem cells are main- tained by self-renewal, which can involve two types of cell division:

A
  1. Asymmetric division
  2. Symmetric division
178
Q

occurs when both daughter cells retain self-renewal capacity

A

Symmetric division

179
Q

refers to cell replication in which one
daughter cell enters a differentiation pathway arise to mature cells, while the other remains undifferentiated

A

Asymmetric division

180
Q

two varieties of stem cells

A
  1. Embryonic stem (ES)
  2. tissue stem cells
181
Q

are the most undifferentiated.
They are present in the inner cell mass of the blastocyst, have virtually limitless cell renewal capacity

A

Embryonic stem (ES)

182
Q

also called adult stem cells, are found in intimate association with the differentiated cells of a given tissue.

A

Tissue stem cells

183
Q

what protects the tissue stem cells by forming microenvironments?

A

stem cell niches

184
Q

cells continuously replenish all the cellular elements of the blood as they exit the circulation, senesce, or are otherwise consumed

A

Hematopoietic stem cells

185
Q

These are multipotent cells that can differentiate into a variety of stromal cells including chondrocytes (cartilage), osteocytes (bone), adipocytes (fat), and myocytes (muscle).

A

mesenchymal stem cells

186
Q

pluripotent stem cells can develope into

A

pancreatic islet cells
Hematopoietic cells
Cardiomyocytes
Neurons
Hepatocytes

note: The pluripotent cells of the inner cell mass, known as ES cells, can be induced to differentiate into cells of multiple lineages.

ES: from fertilized blastocyst

187
Q

total volume and number per cell of mitochondria

A

22%, 1700/cell

Chapter 1 pathology (1 decks)

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