Brainscape's Knowledge GenomeTM

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


See full index

BPS Exam Study > Ch1 The Cell > Flashcards

Ch1 The Cell Flashcards

1
Q

Binding site for transcription factors

A

Promoter and enhancer regions

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

RNAs that are never translated but regulate gene expression through a variety of mechanisms . Includes miRNAs and lncRNAs

A

Noncoding regulatory RNAs

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

Non-protein coding sequence that make up more than a third of the genome. Can move around the genome (“jumping genes”) resulting in a variable copy number and positioning even among closely related species

A

Mobile genetic elements (e.g. transposons)

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

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

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
5
Q

Variants at single nucelotide positions; almost always biallelic (i.e. only 2 choices existing at a given site within the population e.g. A or T)

A

Single nucleotide polymorphisms (SNPs)

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

Form of genetic variation consisting of different numbers of large contiguous stretches of DNA

A

Copy number variations (CNVs)

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

Non-coding RNAs that modulate translation of target messenger RNAs.
Action results in post-transcription silencing by cleavage or translational repression of mRNA

A

miRNAs

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

Non-coding RNA that modulates gene expression by several mechanisms including:
A) facilitating TF binding and promoting gene activation
B) bind TF to inhibit transcription
C) promote chromatin modification
D) act as scaffolds for assembly of protein complexes

A

Long non-coding RNAs (lncRNAs)

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

Nonrandom association of alleles of different loci

(e.g. SNPS may be useful markers if co-inherited with a disease associated polymorphism as a result of physical proximity)

A

Linkage disequilibrium

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

Contain catalase, peroxidase, and other oxidative enzymes. Play a specialised role in the breakdown of very long chain fatty acids, generating hydrogen peroxide in the process

A

Peroxisomes

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

“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
12
Q

intracellular organelles containing degradative enzymes that permit digestion of a wide range of macromolecules

A

Lysosomes

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

3 major classes of cytoskeletal proteins

A
  • Actin microfilaments
  • Intermediate filaments
  • Microtubules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

5-9nm diameter fibrils formed from the globular protein actin (G-actin)

A

Actin filaments

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

10nm diameter fibrils that comprise a large and heterogeneous family that includes keratin proteins and nuclear lamins
Predominantly form ropelike polymers that do not usually actively reorganise

A

Intermediate filaments

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

25nm thick fibrils composed of noncovalently polymerised alpha and beta tubulin dimers organised into hollow tubes
Extremely dynamic with + and - ends

A

Microtubules

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

Form the core of primary cilia

A

Microtubules

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

Seal adjacent epithelial cells together to create a continuous barrier that restricts the paracellular movement of ions and other molecules

A

Occluding (tight) junctions

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

Mechanically attach cells and their cytoskeletons to others cells or the ECM

A

Anchoring junctions (adherens junctions and desmosomes)

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

In this form of anchoring junction, the transmembrane adhesion molecules are associated with intracellular actin microfilaments through which they can also influence cell shape and/or motility

A

Adherens junctions

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

In this form of anchoring junction, the cadherins are linked to intracellular intermediate filaments, allowing extracellular forces to be mechanically communicated (and dissipated) over multiple cells

A

Desmosomes

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

In this form of anchoring junction, integrins are the transmembrane connector proteins which attach to intermediate filaments and link the cytoskeleton to the ECM

A

Hemidesmosomes

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

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

A

Communicating (gap) junctions

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

Proteins and lipids destined for other organelles or extracellular transport are shuttled here from the RER

A

Golgi apparatus

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

Relatively sparse in most cells and primarily exists as the transition zone extending from RER to generate transport vesicles that carry newly synthesised proteins to the Golgi apparatus
More conspicuous in cells synthesising steroid hormone (e.g adrenals) or that catabolise lipid soluble molecules (e.g hepatocytes)

A

Smooth endoplasmic reticulum

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

Responsible for sequestering intracellular calcium

A

Smooth endoplasmic reticulum

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

These enzymes are initially synthesised in the ER lumen and then tagged with mannose-6-phosphate (M6P) within the Golgi apparatus

A

Lysosomal enzymes

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

Degrade cytosolic proteins such as denatured or misfolded proteins as well as any other macromolecule whose lifespan needs to be regulated (may proteins are labelled for destruction by ubiquitin)

A

Proteasomes

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

Phenomenon of rapidly dividing cells increasing their uptake of glucose and glutamine and switching to aerobic glycolysis

A

Warburg effect

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

Growth factor produced by activated macrophages, salivary glands, keratinocytes…
Mitogenic for many cell types’ stimulates epithelial cell migration; stimulates formation of granulation tissue

A

EGF

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

Produced by activated macrophages; keratinocytes…
Stimulates proliferation of hepatocytes and many other epithelial cells

A

Transformation growth factor alpha (TGF-a)

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

Enhances proliferation of hepatocytes and other epithelial cells; increases cell motility
Produced by fibroblasts and most mesenchymal cells, endothelial cells, non-hepatocyte liver cells

A

HGF

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

Produced by mesenchymal cells
Increases vascular permeability
Stimulates proliferation of endothelial cells
Maintenance of normal epithelium (highest expression in epithelial cells adjacent to fenestrated epithelium)

A

VEGF

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

Induces fibroblast; endothelial and SMC proliferation and also chemotactic for these cells

A

PDGF

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

Produced by macrophages, mast cells, endothelial cells..
Chemotactic and mitogenic for fibroblasts; stimulates angiogenesis and ECM protein synthesis

A

Fibroblast growth factors (FGFs)

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

Multiple and often opposing effects depending on tissue “pleiotropic”
Stimulates production of collagen, fibronectin, proteoglycans . Inhibits collagen degradation by decreasing MMP activity and increasing TIMP activity (drives scar formation)
Anti-imflammatory cytokine

A

TGF-beta

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

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

2 major constituents of basement membrane

A

Type 4 collagen
Laminin

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

Collagen types I, II, III and V that form linear fibrils stabilised by interchain hydrogen bonding

A

Fibrillar collagens

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

Enzyme responsible for cross-linking of fibrillar collagens and providing tensile strength.
Dependent on vitamin C

A

lysyl hydroxylase

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

Collagen that contributes to structures of planar BM; help regular collagen-collagen interactions; provide anchoring fibrils that maintain structure of stratified squamous epithelium

A

Nonfibrillar collagens

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

confers the ability of tissues to elastically recoil and return to a baseline structure after physical stress

A

Elastin

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

Form highly hydrated compressible gels that confer resistance to compressible forces
Consist of long polysaccharides called glycosaminoglycans (e.g keratan sulfate and chondroitin sulfate)

A

Proteoglycans

44
Q

Function to enforce the cell cycle checkpoints

A

CDK inhibitors

45
Q

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

A

totipotent stem cells

46
Q

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

A

adult stem cells

47
Q

2 types of cell division used by stem cells for self renewal

A
  • asymmetric division (cell replication in which one daughter cells enters differentiation pathway while the other remains undifferentiated)
  • symmetric division (both daughter cells retain self renewal capacity)
48
Q

2 main types of stem cells

A
  • Embryonic stem cells (totipotent)
  • Tissue stem cells (adult stem cells)
49
Q

Cell cycle phases? (starting with G0 and G1)

A

G0, G1, S, G2, M

50
Q

When does the restriction point occur in the cell cycle?

A

End of G1

51
Q

2 checkpoints of the cell cycle?

A

G1/S
G2/M

52
Q

Tissues where cells may cycle continuously

A

Labile tissues e.g epidermis and GI tract

53
Q

Cells that are quiescent but can enter the cell cycle

A

Stable cells e.g. Hepatocytes

54
Q

Cells that do have the capacity to proliferate

A

Permanent cells e.g. neurons and cardiac myocytes

55
Q

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

A

Stem cells

56
Q

Result from introduction of selected genes into differentiated stem cells which reprogram somatic cells to achieve the “stem-ness” of ES cells

A

Induced pluripotent stem cells

57
Q

2 key growth factors involved in the second phase of liver regeneration

A

Hepatocyte growth factors (HGF)
TGF-alpha
(these are produced by many cell types and act on hepatocytes to stimulate cell metabolism and entry of the cells into the cell cycle)

58
Q

EGFR1 mutations and/or amplification frequently occur in a number of cancers including..

A

lung
head and neck
breast
brain

59
Q

These 2 growth factors are produced by macrophages and epithelial cells, are mitogenic for hepatocytes, fibroblasts and a host of epithelial cell types

A

Epidermal growth factor (EGF)
Transforming growth factor alpha (TGF-alpha)

60
Q

Receptor for this growth factor is MET which has intrinsic tyrosine kinase activity
MET is frequently overexpressed or mutated in tumours, particularly renal and thyroid papillary carcinomas

A

HGF

61
Q

Major angiogenic factor after injury and in tumours

A

VEGF

62
Q

Most important inducer of VEGF production

A

Hypoxia

63
Q

Antibodies against this growth factor are approved the treatment of tumours such as renal and colon cancers

A

VEGF

64
Q

Increased levels of soluble forms of this growth factor receptor in pregnant women may cause preeclampsia

A

VEGFR-1 (also known as s-FLT-1)

65
Q

This growth factor may interact with CD20 affecting Rituxumab therapy

A

Fibroblast Growth Factor (FGF)

66
Q

Pleiotropic GF with a key role in neoplasia, chronic inflammation and keloids

A

TGF-beta

67
Q

What is steatosis?

A

Abnormal accumulations of triglycerides within parenchymal cells

68
Q

Pathological processes involving accumulation of cholesterol or cholesterol esters (name 4)

A
  • Atherosclerosis
  • Xanthomas
  • Cholesterolosis (focal accumulations of cholesterol-laden macrophages in the lamina propria of the gallbladder)
  • Niemann-Pick disease Type C
69
Q

What is Niemann-Pick disease type C?

A

Lysosomal storage diseases caused by mutations affecting an enzyme involved in cholesterol trafficking, resulting in cholesterol accumulation in many organs

70
Q

Intracellular accumulations of these usually appear as rounded, eosinophilic droplets, vacuoles, or aggregates in the cytoplasm

A

Protein

71
Q

Excessive production of immunoglobulins by plasma cells can cause the ER to become hugely distended with large homogenous eosinophilic inclusions called…

A

Russell bodies

72
Q

alpha1-antitrypsin deficiency involves defective transport and secretion of critical…

A

proteins

73
Q

Eosinophilic cytoplasmc inclusion in liver cells that is characteristic of alcoholic liver disease and is composed predominantly of keratin intermediate filaments

A

Alcoholic hyaline

74
Q

What is meant by the term Hyaline

A

Alteration within cells or in the extracellular space that gives a homogenous glassy, pink appearance in routine histologic sections stained with H&E

75
Q

In this disease, glycogen is found in renal tubular epithelial cells, as well as within liver cells, B cells of the islet of Langerhan in the pancreas, and heart muscle cells

A

Diabetes mellitus

76
Q

Excessive intracellular deposits of glycogen are seen in patients with an abnormality in either…

A

glucose or glycogen metabolism

77
Q

The most common exogenous pigment

A

Carbon

78
Q

Accumulation of this pigment blackens the tissues of the lungs (anthracosis) and the involved lymph nodes

A

Carbon

79
Q

What is a lipofuscin

A

An insoluble pigment composed of polymers of lipids and phospholipids in complex with protein.
Not injurious to the cell or functions
Sign of free radical injury and lipid peroxidation

80
Q

Endogenous pigment seen in cells undergoing slow, regressive changes. Seen in the liver and heart of ageing patients or those with severe malnutrition and cancer cachexia

A

Lipofuscin

81
Q

Enzyme involved in formation of melanin

A

Tyrosinase

82
Q

Haemoglobin derived, golden yellow to brown, granular or crystalline pigment; one of the major storage forms of iron

A

Haemosiderin

83
Q

What are the 2 types of stem cells and the difference between them?

A
  • Embryonic stem cells: present in the inner cell mass of the blastocyst. Totipotent (can give rise to every cell in the body)
  • Tissue stem cells (adult stem cells): found in intimate association with the differentiated cells of a given tissue. Normally protected within specialised tissue microenvironments called stem cell niches. Limited lineage potential.
84
Q

Where are stem cell niches located?

A
  • Bone marrow
  • Intestines
  • Bulge region of hair follicles
  • Limbus of the cornea
  • Subventricular zone in the brain
85
Q

What type of stem cells are found in the bone marrow?

A
  • Haematopoeitic stem cells
  • Mesenchymal stem cells (can differentiate into a variety of stromal cells including chondrocytes, osteocytes, adipocytes, myocytes)
86
Q

Which organs are tissue stem cells (Adult stem cells) located in?

A
  • Bone marrow
  • Liver
  • Brain
  • Skin
  • Intestine
87
Q

What is the role of stem cells in the repair of damaged tissues?

A

Regeneration. In tissues such as the skin and intestines, tissue stem cells and their progenitors contribute to the restoration of damaged tissues

88
Q

What is expressed by stem cells and germ cells that makes them resistant to mitotic crisis, and also to avoid the genetic alterations that trigger senescence?

A

Telomerase

89
Q

What are the 2 types of cell division of stem cells?

A
  • Symmetric - both daughter cells remain stem cells (occurs in embyrogenesis or during times of stress)
  • Asymmetric - only one daughter remains a stem cell; the non-stem cell daughter proceeds along some differentiation pathway
90
Q

List five non-coding components of the genome.

A
  • Promoter/enhancer regions
  • binding sites for factors that organise higher order chromatin structures
  • non-coding regulatory RNA (miRNAs, lncRNAs)
  • Mobile genetic elements (eg. transposons)
  • specialised structure regions e.g. centromeres
91
Q

What is epigenetics?

A

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

92
Q

Difference between heterochromatin and euchromatin?

A

Heterochromatin: cytochemically dense and transcriptionally inactive

Euchromatin: disperse and transcriptionally active

93
Q

What is a histone?

A

Protein that DNA wraps around

94
Q

What is the usual effect of histone acetylation, what is the enzyme involved and how is it reversed?

A
  • Histone acetyltransferases (HATs)
  • tend to open the chromatin and increased transcription
  • can be reversed by histone deacetylases (HDACs)
95
Q

What is the role of miRNAs?

A

Modulate translation of target messenger RNAs

Post-transcriptional gene silencing

96
Q

What is the complex that miRNAs associate with to perform post-transcriptional gene silencing?

A

RISC (RNA-induced silencing complex)

97
Q

Roles of proteoglycans in addition to providing compressibility to tissues

A
  • reservoir for growth factors secreted into the ECM
  • some are integral cell membrane proteins that have roles in cell proliferation, migration and adhesion (e.g. by binding and concentrating growth factors and chemokines)
98
Q

Large disulfide linked heterodimer that exists in tissue and plasma forms

Provides the scaffolding for subsequent ECM deposition, angiogenesis and re-epithelialisation in wound healing

A

Fibronectin

99
Q

Most abundant glycoprotein in basement membrane.

Connects to underlying ECM components such as type IV collagen and heparan sulfate

A

Laminin

100
Q

Family of transmembrane heterodimeric glycoproteins composed of alpha and beta subunits. Provide focal attachment to underlying substrates.

Binding elements can also trigger signaling cascades that regulate cell locomotion, proliferation, shape and differentiation

A

Integrins

101
Q

Protein ligands that bind to a distinct family of GPCRs - Frizzled family receptors. Regulars intracellular levels of Beta- catenin

A

Wnt

102
Q

What is the difference between a cadherin and integrin?

A

cadherin is a cell adhesion molecule that is mainly important in cell to cell adhesion, while integrin is a cell adhesion molecule that is mainly important in cell to extracellular matrix adhesion

103
Q

What is the sarcoplasmic reticulum?

A

Specialised smooth endoplasmic reticulum in muscle that is responsible for the cyclic release and sequestration of calcium ions that regular muscle contraction and relaxation, respectively

104
Q

What is the role of ubiquitin in proteasomes?

A

Covalent binding of ubiquitin identifies proteins for destruction by proteasomes

105
Q

Which growth factor may be involved in pathogenesis of pre-eclampsia?

A

VEGF

BPS Exam Study (12 decks)

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