ETA 1 Flashcards
(117 cards)
1
Q
What are the 3 components of the HPA axis?
A
- Hypothalamus
- Anterior pituitary
- Adrenal glands
2
Q
What are factors (re: clotting cascade)?
A
Proteases or co-factors needed to activate the next step in the cascade
3
Q
How does protein C halt the clotting cascade?
A
Breaks down factors 5a and 8a
4
Q
What causes Graves’ disease?
A
Autoimmune stimulation of TSH receptors
5
Q
Which reducing agent is necessary for glutathione (GSH) regeneration?
A
NADPH
6
Q
What is the inactive form of fibrin?
A
Fibrinogen
7
Q
What is fibrinolysis?
A
Breakdown of blood clots
8
Q
Which hormone stimulates RBC production?
A
Erythropoietin
9
Q
Which factor activates fibrin from fibrinogen?
A
Thrombin
10
Q
What is the total number of factors in the clotting cascade?
A
26 (13 x 2)
11
Q
What causes Hashimoto’s disease?
A
Autoimmune destruction of TSH receptors
12
Q
What is the function of SDS-PAGE (a.k.a. protein electrophoresis)?
A
Separate protein fragments by size
13
Q
Compare atheroma and thrombosis.
A
Atheroma: fatty, degenerative material narrowing artery walls by accumulating in the endothelium; may cause thrombosis by rupturing it
Thrombosis: formation of a blood clot inside a blood vessel; may result from an accumulation of atheroma rupturing the endothelium
14
Q
Compare the roles of superoxide dismutase (SOD) and catalase in defence against oxidation.
A
SOD: converts superoxide to oxygen and hydrogen peroxide
Catalase: converts resulting hydrogen peroxide to oxygen and water
15
Q
In addition to BMI, list 3 measurements a dietician might perform.
A
- Skin fold thickness
- Waist-to-hip ratio
- Upper arm circumference
16
Q
What is the function of mass spectrometry?
A
Separate particles by mass-to-charge ratio
17
Q
What is the role of tPA?
A
Convert plasminogen to plasmin
18
Q
What are the 2 hormones produced by the posterior pituitary? (Hint: All Others.)
A
ADH (antidiuretic hormone)
Oxytocin
19
Q
What is the function of the extrinsic pathway?
A
Regulate clotting in tissue that has undergone trauma
20
Q
Define ketosis.
A
A state in which the body breaks down fat for food instead of glucose, producing ketone bodies
21
Q
What does elevated blood creatinine indicate?
A
Kidney malfunction
22
Q
How is metformin metabolised?
A
Is it NOT
Note: it is secreted in its current form
23
Q
How does DNA gel electrophoresis separate DNA fragments by size?
A
- DNA (-ve) is placed on a charged slide
- Migrates toward cathode
- Smaller fragments migrate faster
24
Q
What is the most consistent biochemical abnormality in Addison’s disease?
A
Low Na+ (caused by lack of aldosterone due to damaged adrenal gland)
25
Define atherosclerosis.
Buildup of atheroma inside an artery wall
26
Which factors are involved in the extrinsic pathway? (Hint: 3 X 2.)
3, 7, 10
3a, 7a, 10a
27
What are 2 reasons why the eye is a good site for gene therapy?
Partially protected from the immune system
Hard for viruses to travel from the eye to other parts of the body
28
What is the mechanism of action for rifampicin?
Binds to bacterial RNA polymerase, preventing transcription
29
How does glibenclamide (sulphonylurea) act on insulin?
Promotes insulin secretion
30
What is the function of DNA gel electrophoresis?
Separate DNA fragments by size
31
What does plasminogen do?
Trigger fibrinolysis
32
Describe the process of thrombosis.
Epithelium ruptures -\>
Collagen exposed -\>
Attracts platelets -\>
Platelet plug forms -\>
Clotting cascade triggered
33
How does Sanger chain termination (a.k.a. DNA sequencing) work?
- DNA is separated into 4 vials
- Different ddNTPs added to each vial (i.e., ddATP, ddTTP, ddCTP, and ddGTP)
- Terminate DNA at corresponding nucleotide
- Gel electrophoresis separates fragments by size
34
What is the function of FISH (fluorescence in situ hybridization)?
Use probes to dye specific DNA sequences
35
What is the treatment for paracetamol poisoning?
N-acetylcysteine
36
Define atheroma.
Fatty, degenerative material narrowing artery walls by accumulating in the endothelium
37
Compare the function of type 1 and type 2 ELISA.
Type 1: identify ANTIGEN
Type 2: identify ANTIBODIES
38
What is the function of restriction enzymes?
Cut DNA at specific points
39
Define foam cells.
Macrophages that have attempted to digest oxidised LDL
40
Which common medication might lead to thrombosis due to over-stimulation of the clotting cascade?
Oral contraceptive pill
41
List 5 examples of catabolic pathways.
1. Glycolysis
2. Glycogenolysis
3. Lipolysis
4. Fatty acid oxidation
5. Pentose phosphate pathway
42
Which protein converts plasminogen to plasmin?
tPA (tissue plasminogen activator)
43
What is the function of PCR (a.k.a. polymerase chain reaction)?
Make it easier to examine small sections of DNA by multiplying them
44
How do enzyme assays determine enzyme activity?
Measure color, light diffraction, heat, etc. as a marker for enzyme presence
45
What are the 2 phases of drug metabolism?
Phase I: modification (add or expose a reactive group)
Phase II: conjugation (add a water soluble polar group)
46
What is the function of DNA chip technology (a.k.a. DNA microarray)?
Examine thousands of genes simultaneously (e.g., when comparing normal DNA to diseased DNA)
47
What is the role of glutathione (GSH) in RBC?
Prevent oxidative damage
48
How does type 1 ELISA identify ANTIGENS?
Antibody -\>
Antigen -\>
Antibody tagged w/ enzyme -\>
Color change
49
What is the best technique for comparing normal DNA to diseased DNA?
DNA chip technology (a.k.a. DNA microarray)
50
You need a rapid burst of skeletal activity. What is the best energy source?
Creatine phosphate
51
How does DNA chip technology (a.k.a. DNA microarray) work?
- DNA is inserted in thousands of compartments
- Reacts with relevant probes
- Chip is inserted into a computer and read
52
What is the final product of the clotting cascade?
Cross-linked fibrin
53
What is the first line treatment for Graves's disease (i.e., hyperthyroidism)?
Carbimazole
54
How does type 2 ELISA identify ANTIBODIES?
Antigen -\>
Antibody -\>
Antibody tagged w/ enzyme -\>
Color change
55
What are zymogens?
Inactive precursors of enzymes
56
What is the function of karyotyping?
Display entire set of chromosomes
57
How does PCR (a.k.a. polymerase chain reaction) work?
- DENATURE: heat DNA to separate strands
- ANNEAL: decrease heat so primer can stick
- TRANSCRIBE: increase heat so polymerase can add free nucleotides
- Process is repeated to yield millions of copies
58
What would you use to cut DNA at specific points?
Restriction enzymes
59
How would you prepare a karyotype?
- Arrest chromosomes at metaphase
- Tag them with dyes
- Photograph them
- Arrange photographs in order
60
How would increased ACTH (e.g., in Addison’s) lead to darker skin?
Excessive ACTH exhibits MSH-like activity
Note: MSH = Melanocyte Stimulating Hormone
61
What is the first factor of the intrinsic pathway?
Factor 11
62
What are the 3 types of ketone bodies?
1. Acetone
2. Acetoacetate
3. Beta-hydroxybutyrate
63
Which factors are involved in the intrinsic pathway? (Hint: 4 X 2.)
8, 9, 10, 11
8a, 9a, 10a, 11a
64
How does mass spectrometry separate particles by mass-to-charge ratio?
- Ionisation
- Acceleration
- Deflection (via magnet)
- Detection
65
What are the 2 sources of ketone bodies?
1. Fat in adipose tissue
2. Ketogenic amino acids
66
What is the best technique for determining the absence or presence of specific areas of a gene?
FISH (fluorescence in situ hybridization)
67
What are the 6 hormones of the anterior pituitary? (Hint: TP FLAG.)
TSH (thyroid stimulating hormone)
PRL (prolactin)
FSH (follicle stimulating hormone)
LH (luteinising hormone)
ACTH (adrenocorticotropic hormone)
GH (growth hormone)
68
Which factors are involved in the common pathway? (Hint: 5 X 2.)
5, 10, 13, prothrombin, fibrinogen
5a, 10a, 13a, thrombin, fibrin
69
How is a clot able to form from the activation of a very small amount of initial factor?
Activation of thrombin promotes further activation of factors 5, 8, 11, and 13 (i.e., positive feedback loop)
70
Define thrombosis.
Formation of a blood clot inside a blood vessel
71
How does gene therapy work?
- Add gene to a virus modified not to replicate
- Insert virus into cell
Note: can be carried out in vivo (e.g., bone marrow) or ex vivo (e.g., stem cells)
72
What is the function of phase I drug metabolism (i.e., modification)?
Add or expose a reactive group
73
Which disease do protruding eyeballs indicate?
Graves’ disease
74
What is the first line treatment for Hashimoto's disease (i.e., hypothyroidism)?
Oral thyroxine
75
Describe the reactions of the HPA axis.
Hypothalamus
(Secretes)
Corticotrophin-releasing hormone (CRH)
(Stimulates)
Anterior pituitary
(Releases)
Adrenocorticotropic hormone (ACTH)
(Stimulates)
Adrenal glands
(Release)
Cortisol
(Negative feedback)
76
The presence of which protein in the bloodstream is a biomarker for myocardial infarction?
Troponin
77
What is the function of Sanger chain termination (a.k.a. DNA sequencing)?
Determine the sequence of nucleotides
78
Which activated enzyme triggers fibrinolysis?
Plasmin
79
What test would you use for the DDx of hypoadrenalism?
Short synacthen test
80
What does thrombin do?
Activates fibrin from fibrinogen
81
What is the best technique for identifying polyploidies, aneuploidies, or large chromosomal defects?
Karyotyping
82
Which pathway regulates clotting in damaged endothelial lining?
Intrinsic
83
What is the first factor of the extrinsic pathway?
Factor 3
84
What is the common point for the 2 pathways of the clotting cascade?
Factor 10
85
What type of glial cells produce cerebrospinal fluid?
Ependymal cells
86
List 5 components of atheroma.
1. Oxidised LDL
2. Macrophages
3. Foam cells
4. Calcium salts
5. Fibrous tissue
87
How does fibrin cause clotting?
Forms a mesh which traps blood cells
88
What is the mechanism of action for tetracycline?
Competes with tRNA at A site of bacterial ribosomes, inhibiting protein synthesis
89
What are the 2 pathways of the clotting cascade?
1. Intrinsic
2. Extrinsic
90
How does SDS-PAGE (a.k.a. protein electrophoresis) separate protein fragments by size?
- Proteins (-ve or +ve) are placed on a charged slide
- Migrates towards end
- Smaller fragments migrate faster
91
List 3 mechanisms of halting the clotting cascade.
1. DILUTION of factors by blood flow (followed by removal in the liver)
2. BREAKDOWN of factors by proteases
3. INHIBITION of factors by binding
92
Anti-coagulants reduce the risk of which progressive neurological disorder?
Dementia
93
What is the best technique for identifying antigens or antibodies?
ELISA (a.k.a. immunoassays)
94
What is the inactive form of thrombin?
Prothrombin
95
Which breakdown product of muscle tissue is an indicator of kidney malfunction?
Creatinine
96
Why can’t cellulose be broken down by the body?
- Contains beta-glyosidic bonds
- GI tract only has enzymes for breaking down alpha-glycosidic bonds
97
Lack of which enzyme causes lactose intolerance by making it harder to metabolize lactose into glucose and galactose?
Lactase
98
What is the function of phase II drug metabolism (i.e., conjugation)?
Add a water soluble group
99
Compare anabolic and catabolic reactions.
Anabolic: build larger molecules from smaller ones, require energy
Catabolic: break larger molecules into smaller ones, release energy
100
Explain how G6PD deficiency causes hemolysis.
Decreased G6PD -\>
Deceased synthesis of NADPH (powerful reducing agent) in pentose phosphate pathway -\>
Decreased regeneration of glutathione (powerful anti-oxidant) in RBC -\>
Oxidative damage to RBC -\>
Hemolysis
101
Define embolism.
Lodging of an embolus (blockage-causing material) inside a blood vessel
102
How does disulfiram treat alcoholism?
Inhibits acetaldehyde dehydrogenase, leading to acetaldehyde buildup and hangover-like side effects
103
How might the oral contraceptive pill lead to thrombosis?
Over-stimulation of the clotting cascade
104
What is the function of the intrinsic pathway?
Regulate clotting in damaged endothelial linings
105
List 5 examples of anabolic pathways.
1. Gluconeogenesis
2. Glycogenesis
3. Ketogenesis
4. Fatty acid synthesis
5. Cholesterol synthesis
106
What test would you use for the DDx of hyperadrenalism?
Dexamethasone suppression test (DST)
107
What is the main function of the HPA axis?
Stress response
108
What is the toxic metabolite of alcohol?
Acetaldehyde
109
What is gene therapy?
Replacing a malfunctioning gene with a modified gene
110
What is the best technique for determining enzyme activity?
Enzyme assays
111
What is the mechanism of action for methotrexate?
Competitively inhibits DHFR, blocking the folate pathway Note: folate is essential for DNA synthesis
112
How does Antithrombin III (AT3) halt the clotting cascade?
Inhibits thrombin by binding to it
113
What is the mechanism of action for penicillin?
Prevents bacterial cell wall from cross-linking, causing lysis
Note: only affects gram-positive bacteria
114
How does metformin (biguanide) act on insulin?
Promotes insulin sensitization in liver and muscle
115
Which pathway regulates clotting in tissue that has undergone trauma?
Extrinsic
116
How does classic hemophilia cause bleeding?
Defective factor 8 hinders clotting
117
A toddler presents with seizures, intellectual delay, and behavioral problems. They smell musty. You suspect PKU. Which gene is mutated and which enzymatic defect results?
PAH gene
Low levels of the enzyme phenylalanine hydroxylase
