combo BIOCM 2 E1
Which statement is TRUE about the Hb form the predominates in arterial blood? A. Not bound to BPG B. Contains carbamate derivatives C. Has His146-Asp94 and Tyr145-Val98 non-covalent bonds D. It is in the T state E. Its His146 has an abnormal high pKa
A. Not bound to BPG
Which protease performs a single step catalysis? A. Pepsin B. Elastase C. Cathepsin D. Papain
A. Pepsin
A deficiency of von willebrand factor (VWF) will affect which phase of hemostasis? A. Phase 1 - Primary hemostasis B. Phase 1- Secondary hemostasis C. Phase 2 - Anti coagulation D. Phase 3 - Fibrinolysis
A. Phase 1 - Primary hemostasis
Why are cofactors sometimes necessary for catalysis? A. They add unique chemical groups B. They are organic C. They are inorganic D. They add positive charges
A. They add unique chemical groups
A major difference between neurotransmitter signaling versus hormone-mediate signaling is that hormonal responses act at distant target tissues and are long-lived: A. True B. False
A. True
With this technique you can determine in a semi-quantitative manner the difference in expression levels of a protein in two different tissues. A. Western Blot B. Enzyme-linked immuno-absorbent assay (ELISA) C. SDS-PAGE D. Immunohistochemistry E. Immunofluorescence
A. Western Blot
Which picture represents a case where substrate binding is unaffected (Km is the same), but addition of excess substrate will not relieve inhibition?
D
In the fasting state, which one of the following is utilized by the liver for gluconeogenesis? (A) Glycerol (B) Even-chain fatty acids (C) Liver glycogen (D) Ketone bodies (E) Essential fatty acids
(A) Glycerol
Blood acidosis can precipitate a sickle cell anemia crisis by: A. Decreasing Hb solubility B. Increasing the affinity of Hb for O2 C. Favoring the conversion from the T to the R state D. Shifting the O2 binding curve to the left E. Decreasing the ability of BPG to bind to Hb
A. Decreasing Hb solubility
Product 5 is a feedback inhibitor which enzyme should it target?
A. E1
Which hemostasis disorder is treatable by warfarin? A. Factor V Leiden B. Hemophilia A C. Hemophilia B D. Exposure to warfarin E. Thrombocytopenia (low platelet count)
A. Factor V Leiden
Which of the following can be both a Bronsted acid and a Bronsted base in pure water? A. H2PO4- B. H2CO3 C. NH3 D. NH4+ E. Cl-
A. H2PO4-
A medical student has been studying for exams and neglects to eat anything for 12 hours. At this point, the student opens a large bag of pretzels and eats every one of them in a short period. Which one of the following effects will this meal have on the student's metabolic state? (A) Liver glycogen stores will be replenished. (B) The rate of gluconeogenesis will be increased. (C) The rate at which fatty acids are converted to adipose triacylglycerols will be reduced. (D) Blood glucagon levels will increase. (E) Glucose will be oxidized to lactate by the brain and to CO2 and H2O by the red blood cells.
(A) Liver glycogen stores will be replenished. After a meal of carbohydrates (the major ingredient of pretzels), glycogen is stored in the liver and in muscle, and triacylglycerols are stored in adipose tissue. Owing to the rise in glucose level in the blood (from the carbohydrates in the pretzels), insulin is released from the pancreas, and the level of glucagon in the blood decreases. Because blood glucose levels have increased, there is no longer a need for the liver to synthesize glucose, and gluconeogenesis decreases. The change in insulin to glucagon ratio also inhibits the breakdown of triacylglycerols and favors their synthesis. The brain oxidizes glucose to CO2 and H2O, whereas the red blood cells produce lactate from glucose because red blood cells cannot carry out aerobic metabolism.
The major precursor of urea in the urine (A) Protein (B) Triacylglycerol (C) Liver glycogen (D) Muscle glycogen
(A) Protein
The largest amount of stored energy in the body (A) Protein (B) Triacylglycerol (C) Liver glycogen (D) Muscle glycogen
(B) Triacylglycerol
A physician working in a refugee camp in Africa notices a fair number of children with emaciated arms and legs, yet a large protruding stomach and abdomen. An analysis of the children's blood would show significantly reduced levels of which one of the following as compared with those in a healthy child? (A) Glucose (B) Ketone bodies (C) Albumin (D) Fatty acids (E) Glycogen
(C) Albumin The children are exhibiting the effects of kwashiorkor, a disorder resulting from adequate calorie intake but insufficient calories from protein. This results in the liver producing less serum albumin (because of the lack of essential amino acids), which affects the osmotic balance of the blood and the fluid in the interstitial spaces.
The primary source of carbon for maintaining blood glucose levels during an overnight fast (A) Protein (B) Triacylglycerol (C) Liver glycogen (D) Muscle glycogen
(C) Liver glycogen
The energy source reserved for strenuous muscular activity (A) Protein (B) Triacylglycerol (C) Liver glycogen (D) Muscle glycogen
(D) Muscle glycogen
A patient is brought to the emergency room after being found by search and rescue teams. He was mountain climbing, got caught in a sudden snowstorm, and had to survive in a cave. He had no food for 6 days. In adapting to these conditions, which metabolic process has increased rather than decreased? (A) The brain's use of glucose (B) Muscle's use of ketone bodies (C) The red blood cells' use of glucose (D) The brain's use of ketone bodies (E) The red blood cells' use of ketone bodies (F) Muscle's use of glucose
(D) The brain's use of ketone bodies
A 32-year-old male is on a weight-maintenance diet, so he does not want to lose or gain any weight. Which amino acid must be present in the diet so the patient does not go into a negative nitrogen balance? (A) Alanine (B) Arginine (C) Glycine (D) Threonine (E) Serine
(D) Threonine The lack of one essential amino acid will lead to a negative nitrogen balance because of increased protein degradation to supply that amino acid for the ongoing protein synthesis. Of the amino acids listed, only threonine is an essential amino acid (alanine can be synthesized from pyruvate [which can be derived from glucose], arginine is produced in the urea cycle using aspartic acid and the amino acid ornithine, glycine is derived from serine, and serine is derived from 3-phosphoglycerate, which can be produced from glucose).
Sweating reduces body heat through evaporative cooling, this happens because water has a very high: A. Heat of evaporation B. Viscosity C. Surface tension D. Dielectric constant E. High thermal conductivity
A. Heat of evaporation
Which immunoglobulin has a secretory component? Which one is pentameric? A. IgA; IgM B. IgM; IgA C. IgG; IgM D. IgE; IgG E. IgD; IgM
A. IgA; IgM
Based on the reaction above, hyperventilation will (fill the blank) blood pH: A. Increased B. Decreased C. Not affect
A. Increased
When Hb is converted from the T form to the R form: A. It becomes more acidic B. PKa if His 146 increases C. Carbamino formation is promoted D. Binding of BPG is favored E. Will predominate in venous blood
A. It becomes more acidic
Which of the following is true about the Na/K+ pump? A. It is an ATPase B. Is a symport system C. Moves Na+ in any direction D. Generates an electrically neutral system E. Expels K+ to the extracellular space
A. It is an ATPase
Which of the following GAGs will accumulate in the lysosome of a patient suffering from Morquio Syndrome B, which is characterized by a deficiency in the enzyme beta-galactosidase? A. Keratan sulfate B. Chondroitin sulfate C. Heparan sulfate D. Hyaluronate E. Heparin sulfate
A. Keratan sulfate
In the diagram on the left, net water movement occurs from : A. Left to right B. Right to left C. No net movement
A. Left to right
Which of the following cofactors always requires the presence of a lysine in the active site? A. Lipoid acid (alpha-lipoate) B. Vitamin K C. Niacin/NAD (B3) D. Ascorbic Acid (C)
A. Lipoid acid (alpha-lipoate)
Which enzyme binds its substrate more strongly than its inhibitor? (For this question, please simplify Ki to be inhibitor concentration for half maximum inhibition)
A
One such change is the activation of phosphatases, which remove phosphate groups linked to serine or threonine residues in enzymes related to storage (activation) and mobilization (inhibition). The action of a phosphatase on these enzymes, positive or negative, is an example of what type of enzyme regulation? A. Covalent modification B. Zymogen activation C. Allosteric interactions D. Protein-protein interactions E. Isoenzymes
A. Covalent modification
Based on the pKA values below, the strongest acid is the one with pKA: A. 4.0 B. 6.0 C. 8.0 D. 10.0 E. 12.0
A. 4.0
Matrix metalloproteinases (MMPs) are extracellular enzyme that degrade extracellular matrix. As the name implies, they require metal cofactors, usually Zn2+ or Ca2+ for activity. The MMPs do not bind the metal ion in the cytoplasm, but only after release in the extracellular space. What term describes the cytoplasmic form of MMP? A. Apoenzyme B. Coordinated center C. Holoenzyme D. Active form
A. Apoenzyme
Which amino acid is a zwitterion at pH 3.0? A. Aspartic acid B. Lysine C. Arginine D. Histadine
A. Aspartic acid Verify
A patient was admitted to the hospital with increased breathlessness, Arterial blood gas measurements revealed pO2 of 6 kPa (normal = 10.5 - 13.5 kPa), pCO2 of 8.4 pKa (4.6 -6.0 kPA), a blood pH of 7.28 (normal = 7.37 - 7.44), and bicarbonate concentration of 35 mmol/L (normal = 23-30 mmol/L). What is the most likely diagnosis of this patient? A. Chronic obstructive pulmonary disease B. Diabetic ketoacidosis C. Kidney failure D. Lactic acid accumulation in muscles E. Hyperventilation
A. Chronic obstructive pulmonary disease
What is the best explanation for your data? A. Compound A makes proteins heat sensitive B. Compound A destabilizes multi-subunit enzymes C. Temperature increases unfold proteins, enzymes lose activity D. Your control reaction should be done at a different temperature
A. Compound A makes proteins heat sensitive
Which of the following has an antagonistic action to adenylate cyclase? A. Cyclic adenosine monophosphate B. Protein kinase C. The active GTP alpha subunit of a G protein D. Phosphodiesterase (PDE)
A. Cyclic adenosine monophosphate
His 146 contributes to about 50% of the Bohr effect. Which of the following would be true of a mutant hemoglobin lacking this residue? A. Regulation of O2 release is unaffected B. Compromised ability to assume the T state/Will never be able to assume the T state C. Affinity for O2 is decreased D. ___Hydric transport will be impaired
B. Compromised ability to assume the T state/Will never be able to assume the T state
De-phosphorylation of the Na+/K+ pump results in: A. Three Na+ are released to the extracellular space B. Conformational change releasing two K+ into the intracellular space. Allowing for three Na+ from the cytoplasm being accepted into the pump C. Opening the pump towards the extracellular space D. Release of two K+ into the extracellular space
B. Conformational change releasing two K+ into the intracellular space. Allowing for three Na+ from the cytoplasm being accepted into the pump
An individual is in Mexico City at an altitude of 7,350 feet. He is having trouble breathing with insufficient O2 being delivered to his tissues by Hb. Which treatment could alleviate his conduction? A. A drug that induces metabolic alkalosis B. A drug that increases BPG production C. Start hyperventilating D. Hydroxyurea (induces gamma chain synthesis) E. A drug that induces the synthesis of beta chains
B. A drug that increases BPG production
The catalytic method in which an acyl-enzyme intermediate (aka tetrahedral adduct) is formed is the one in which: A. Water acts as a nucleophile B. An enzyme residue acts as a nucleophile C. A zinc atoms helps to polarize a water molecule D. Catalysis occurs as a single step
B. An enzyme residue acts as a nucleophile
Leeches are still used medically around the globe. By removing pooled blood, they actually improve blood flow to tissues. Leeches secrete hired in that interferes with clotting. How does hirudin work? A. Binds irreversibly to prothrombin B. Binds to and irreversibly inactivate thrombin C. Binds to and irreversibly inactivate transglutaminase (FXIII) D. Binds to fibrinogen and prevent fibrin formation E. Increases secretion of tissue plasminogen activator from endothelial cells
B. Binds to and irreversibly inactivate thrombin
The underlying mechanism by which GAGs promotes the formation of gel-like substances in the ECM is: A. Charge attraction between GAG chains B. Charge repulsion between GAG chains C. Hydrogen bonding between GAG chains D. Covalent cross-linking between GAG chains E. Hydroxylation of adjacent GAG chains
B. Charge repulsion between GAG chains
A family has been using a propane heater in an enclosed apartment during winter. One morning, a family member was difficult to awake an complained of a strong headache and being tired. His mucous membranes are cherry red color. These symptoms are the result of the following; A. Increased O2, delivery to tissues B. Decreased O2, delivery to tissues C. Increased blood flow to the brain D. Decreased blood flow to the brain E. Decreased O2 affinity to Hb
B. Decreased O2, delivery to tissues
A 6 year old African American boy complains of acute abdominal pain that began after playing in a football game. He denies being tackled forcefully. He has a history of easy fatigue and several similar episodes of pain after exertion, with the pain mostly restricted to his extremities. Microscopic evaluation of his blood would reveal the following cellular abnormalities? A. Increased WBC count B. Deformed RBC C. Decreased WBC count D. Erythrocytosis (Increased RBC count) E. Reduced platelet count
B. Deformed RBC
You work in clinical reference laboratory and you need to test 400 blood samples from males who are undergoing routinely prostate check-ups. What would you be looking for and which of the following tools would you use? A. Western Blot B. Enzyme linked immune absorbent assay C. Mass spectroscopy D. Immunohistochemistry E. SDS-PAGE
B. Enzyme linked immune absorbent assay
Which of the following steps will be most directly affected by a mutation in Asp 102 in a serine protease? A. Substrate specificity B. Generation of the alkoxide nucleophile C. The capacity of His 57 to act as an acid D. Strength of substrate binding
B. Generation of the alkoxide nucleophile
Isohydric transport of CO2 from tissues to lung refers to: A. Free CO2 dissolved in plasma B. HCO3- in plasma C. Carbamino (or carbamate) compounds D. The Bohr effect E. Protonation of His 146
B. HCO3- in plasma
The uptake of a substance across a biological membrane by simple diffusion: A. Exhibits saturation kinetics B. Is at a rate which is a linear function of the concentration difference across the membrane C. Can be inhibited by blockers of oxidative phosphorylation D. Is mediated by membrane proteins which bind the substance
B. Is at a rate which is a linear function of the concentration difference across the membrane
Thermolysin and Carboxypeptidase A are examples of this type of proteases: A. Serine proteases B. Metalloproteases C. Thioproteases (Aka cysteine proteases) D. Aspartyl Proteases
B. Metalloproteases
Clinical testing of a blood sample can reveal problems in either the extrinsic or the intrinsic pathways. Prothrombin time (PT) will reveal a problem in the extrinsic pathway; activated partial thromboplastin time (aPTT) reveals a problem in the intrinsic pathway. Which scenario would you expect of a person with hemophilia A? A. Normal PT, Normal aPTT B. Normal PT, Prolonged aPTT C. Prolonged PT, Normal aPTT D. Prolonged PT, Prolonged aPTT E. Accelerated PT, Prolonged aPTT
B. Normal PT, Prolonged aPTT
Clinical testing of a blood sample can reveal problems in either the extrinsic or the intrinsic pathways. Prothrombin time (PT) will reveal a problem in the extrinsic pathway; activated partial thromboplastin time (aPTT) reveals a problem in the intrinsic pathway. Which scenario would you expect of a person with hemophilia A? A. Normal PT, normal aPTT B. Normal PT, prolonged aPTT C. Prolonged PT, normal aPTT D. Prolonged PT, prolonged aPTT E. Accelerated PT, prolonged aPTT
B. Normal PT, prolonged aPTT
Which of the following best illustrates the relationship between an epitope and an antigen? A. An epitope is the whole protein while an antigen is a portion of the epitope B. One antigen can contain many epitope C. A group of antigens comprise an epitope D. An antigen and an epitope are exactly the same E. An epitope plus an antigen form an antigenic determinant
B. One antigen can contain many epitope
The movement of glucose across the erythrocyte membrane is an example of: A. Non-mediated transport that occurs through simple diffusion B. Passive mediated transport (GLUT1) C. Direct active mediated transport D. Indirect active mediated transport E. Altered molecule mediated transport (group translocation)
B. Passive mediated transport (GLUT1)
A patient suffers from bone pain, recurring infections, renal dysfunction and anemia. Urinalysis and blood tests from this patient show the presence of abnormal immunoglobulins in blood and urine. After further testing, a diagnosis of multiple myeloma is reached. Which of the following is correct about the abnormal immunoglobulins found in this patient? A. They lack amino terminals B. They cannot bind to macrophage receptors C. They lack constant regions D. They lack variable regions E. They can either be episode or delta chains
B. They cannot bind to macrophage receptors
Caspases, which are involved in apoptosis, belong to which category of proteases? A. Metalloproteases B. Thioproteases C. Aspartyl proteases D. Serine proteases
B. Thioproteases
A kinase move a phosphate from ATP to another compound. It is an example of which class of enzyme? A. Oxidoreductase B. Transferase C. Hydroplane D. Lyase E. Isomerase
B. Transferase
Membrane receptors that attach phosphates to specific amino acids in protein are: A. Only found in bacteria B. Tyrosine kinase receptors C. A sub-class of G protein-coupled signal receptors D. G-protein coupled receptor
B. Tyrosine kinase receptors Could also G-protein coupled receptor
Which liquid will have more surface tension? A. Ethanol B. Water C. Both will have equal surface tension D. None of them has significant surface tension
B. Water
Which of the following hydrogens CANNOT participate in hydrogen bonding? A. X-F-H B. X-C-H C. X-N-H D. X-O-H
B. X-C-H
Matrix metalloproteinases are a class of endopeptidases that have important roles in cell migration, angiogenesis and tissue remodeling. They are produces as a pro-protein that becomes active upon secretion into the extracellular space. This exemplifies which type of regulation? A. Covalent modification B. Zymogen activation C. Allosteric interactions D. Protein-protein interactions E. Isoenzymes
B. Zymogen activation
Flip card
Based on the graph the uptake of a substance across a biological membrane by pumps exhibits A or B kinetics? A
A. 4.0
Based on the pKa values below, the strongest acid is the one with pKa: A. 4.0 B. 6.0 C. 8.0 D. 10.0 E. 12.0
Digesting an immunoglobulin with papain results in the release of three fragment - the two Fabs and the Fc. Which of the following if affected by this digestion? A. Specificity for the antigen B. Binding to the epitope C. Antigen agglutination D. Formation of haptenic determinants E. Crossing of Fc through the placenta
C. Antigen agglutination
In isohydric transport, CO2 inside erythrocytes is converted by carbonic anhydrase to carbonic acid, which in turn dissociates into H+ and HCO3-. As the HCO3- exits the erythrocyte, a Cl- enters to preserve the balance of charges inside the cell. The transport mechanism involved in this process is: A. Symport, active B. Antiport, active C. Antiport, passive D. Uniport, active
C. Antiport, passive
You graph the data in a double-reciprocal (lineweaver-burk) format. How will you find the Vmax? A. Slope B. -Slope C. 1/y intercept D. -1/X intercept E. Y intercept/ x intercept
C. 1/y intercept
If a weak acid is 91% neutralized at pH 5.7, what is the pKa of this acid? A. 2.7 B. 3.7 C. 4.7 D. 5.7 E. 6.7
C. 4.7
Cardiac glycosides, such as ouabain, interfere with the Na+/K+ pump by directly inhibiting its phosphorylation, meaning that they inhibit: A. Release of Na+ to the external surface B. Uptake of K+ from the external medium C. A conformational change responsible for movement of Na+ from the cytosol to the external medium D. Regeneration of ATP from ADP within the cell
C. A conformational change responsible for movement of Na+ from the cytosol to the external medium
Bacteria grown at 15 degrees Celsius contain a different fatty acid composition in their membranes as compared to bacteria grown at 37 degrees Celsius. Which one of the following would best represent the composition of the fatty acids at these two different temperatures? A. Bacteria at the lower temperature would contain a higher percentage of saturated fatty acids than bacteria grown at the higher temperature B. Bacteria grown at the lower temperature would have a higher percentage of long chain fatty acids than bacteria grown at the higher temperature C. Bacteria grown at the lower temperature would have a higher percentage of unsaturated fatty acids than bacteria grown at the higher temperature D. Bacteria grown at the lower temperature would have an increased level of cholesterol as compared to bacteria grown at the higher temperature E. Bacteria grown at the lower temperature would have a decreased level of cholesterol as compared to bacteria grown at the higher temperature
C. Bacteria grown at the lower temperature would have a higher percentage of unsaturated fatty acids than bacteria grown at the higher temperature
Citrate and EDTA are both chelators able to bind divalent cations. Which process of coagulation are they likely to inactivate? A. Addition of gamma-carboxyglutamate in liver B. Action of the vitamin K reductase C. Binding of clotting factors to negatively charged phospholipids D. Vasoconstriction by thromboxane A2 release E. Activation of protein C by thrombin-thrombomodulin
C. Binding of clotting factors to negatively charged phospholipids
A prominent feature of the beta sheet is: A. It is rich in consecutive bulky amino acids B. Hydrogen bonds perpendicular to the polypeptide backbone C. Contains 3.6 amino acids per turn D. Stabilized by stretches of positively charged amino acids E. Extensive hydrogen bonding with surrounding water molecules
C. Contains 3.6 amino acids per turn
Mucopolysaccharidoses are inherited lysosomal storage disease caused by: A. Increased rate of synthesis of the carbohydrate portion of a proteoglycan B. The synthesis of polysaccharides with an altered structure C. Defects in the degradation of the proteoglycans GAGs D. The synthesis of abnormally small amounts of protein cores E. An insufficient amount of proteolytic enzymes
C. Defects in the degradation of the proteoglycans GAGs
Von willebrand factor binds which of the following in phase 1, primary hemostasis A. Thromboxane A2 B. Fibrin C. Endothelial phospholipid D. Red blood cell phospholipid
C. Endothelial phospholipid
Allosteric and cooperative regulation are both manners by which binding of a compound outside of the active site can control the activity of the active site. What concept explains these phenomena? A. Most enzymes have multiple active sites B. Enzymes fold into active conformation upon binding substrate C. Enzymes can undergo shifts in conformation D. Enzymes can bind covalently to substrates
C. Enzymes can undergo shifts in conformation
Tyrosine hydroxylase (TH) is the rate limiting enzymes in the synthesis of catecholamine neurotransmitters. Each of the major catecholamines, dopamine, norepinephrine, and epinephrine can inhibit TH. What type of regulation is this? A. Allosteric B. Covalent C. Feedback D. Isoenzyme E. Protein-protein
C. Feedback
Which of the following acids can be used to prepare a buffer? A. HCl (Hydrochloric) B. H2SO4 (Sulfuric) C. H2CO3 (Carbonic) D. HCLO4 (Perchloric) E. HNO3 (Nitric)
C. H2CO3 (Carbonic)
Which of the following GAGs will accumulate in the lysosome of a patient suffering from Hunter syndrome, which is characterized by a deficiency in the enzyme iduronate sulfatase? A. Keratan sulfate B. Chondroitin sulfate C. Heparan sulfate D. Hyaluronate E. Heparin sulfate
C. Heparan sulfate
Refer to the following biochemical reaction below. This type of reaction is mediated by A. Oxidoreductase B. Transferase C. Hydrolase D. Lyase E. Isomerase
C. Hydrolase
Which one is TRUE about the fluid-mosaic model of membrane structure: A. Ionic and polar heads of lipid molecules are in the interior core of the membrane B. The membrane is symmetrical in that the outer face is identificar to the cytoplasmic face in terms of phospholipid and protein composition C. Integral membrane proteins are in contact with the fatty acid chains of the phospholipid D. Peripheral membrane proteins are situated in the hydrophobic core
C. Integral membrane proteins are in contact with the fatty acid chains of the phospholipid
There is a cysteine in the active site of aldehyde dehydrogenase to which disulfiram is covalently linked. Based only on this information, what can you confidently state about the type of inhibition disulfiram displays? A. Non-specific inhibitor B. Non-competitive inhibitor C. Irreversible inhibitor D. Allosteric inhibitor
C. Irreversible inhibitor
Which is a characteristic feature of hemostasis (clotting)? A. Hemostasis requires rapid induction of gene products B. It is stimulated by hypotension C. It is activated by anionic surfaces on blood vessel wall D. Fibrin is the central enzyme component in the cascade
C. It is activated by anionic surfaces on blood vessel wall
When an enzyme induces strain into a substrate to help form the transition state, what is the thermodynamics basis for more rapid catalysis? A. Change in reaction equilibrium B. Alignment of substrates with active site C. Lower energy of activation D. Change in free energy between product and reactant
C. Lower energy of activation
Methemoglobinemia, aka chocolate blood cyanosis, is a condition characterized by higher than normal levels of methemoglobin. In addition to chocolate brown colored blood, clinical manifestations also include shortness of breath, cyanosis, palpitations, confusion, headaches and dizziness. Which enzyme is most likely deficient in a chocolate blood cynanosis is patient? A. Carbonic anhydrase B. BPG mutase (synthesizes BPG) C. Methemoglobin reductase D. Lysyl oxidase
C. Methemoglobin reductase
Which one of the following membranes contains the highest percentage lipid? A. Endoplasmic reticulum B. Erythrocytes plasma membrane C. Myelin sheath D. Inner mitochondrial membrane E. Outer mitochondrial membrane
C. Myelin sheath
Which of the following is able to degrade fibrin in the hard clot? A. Thrombin B. Plasminogen C. Plasmin D. Factor X E. Factor XIII
C. Plasmin
In a patient with chronic obstructive pulmonary disease, which of the following alternatives is true about the carbonic anhydrase reaction? A. Blood proton concentration decreases B. Carbonic anhydrase reaction is shifted to the left C. Production of carbonic acid is increased D. The carbonic anhydrase reaction is unaffected E. Blood bicarbonate concentration decreases
C. Production of carbonic acid is increased
The PIP2 signaling system begins with activation of phospholipase C which initiates a sequence of events including all of the following except: A. Activation of IP3 by a phosphatase B. Increase in Ca2+ intracellular levels C. Release of diacylglycerol (DAG) from a membrane lipid (PIP2) D. Activation of protein kinase C (PKC) E. Phosphorylation of target proteins
C. Release of diacylglycerol (DAG) from a membrane lipid (PIP2)
With this technique you can easily determine if a patient has full blown sickle cell anemia or is just a carrier. A. Western Blot B. Enzyme-linked immuno-absorbent assay (ELISA) C. SDS-PAGE D. Immunohistochemistry E. X-ray crystallography
C. SDS-PAGE
Brings distant amino acids closer together: A. Primary B. Secondary C. Tertiary D. Quaternary
C. Tertiary
Level of structure found in hemoglobin but not in insulin: A. Primary B. Secondary C. Tertiary D. Quaternary
C. Tertiary
Which of the following statements about facilitated diffusion is FALSE: A. A plot of rate of uptake by cells of the pertinent substance would be expected to give a hyperbolic curve B. Depending on condition, transport could occur in either directive across the membrane C. The process can allow a substance in cells to be accumulated against a concentration gradient D. An interaction between the substance transported and a membrane component is likely to occur E. Competitive inhibition of the transport of a substance by its chemical analogs is likely to occur
C. The process can allow a substance in cells to be accumulated against a concentration gradient
Acute poisoning with ferrous sulfate causes coagulopathy. Free ferrous iron (+3 state) in excess, not bound to transferrin due to saturation, results in an inability to convert fibrinogen to fibrin. The activity of which enzyme is affected? A. Transglutaminase (FXIII) B. Vitamin K reductase C. Thrombin D. Y-Glutamyl carboxylase
C. Thrombin
Intra-abdominal thromboses associated with hypofibrinolysis are a characteristic feature of Budd-Chiari Syndrome (BCS). The splanchnic veins (portal, splenic, mesenteric, supra-hepatic) are usually affected, often first detected by liver insufficiency. BCS is a rare disorder and over 70% of cases have unknown etiology. Examination generally shows lack of activity of a phase 3 enzyme. Which of the following enzyme deficiencies would you test for in a patient with BCS? A. Prothrombin (Factor II) B. Tissue factor (Factor VII) C. Tissue plasminogen activator D. Factor X E. Factor XIII
C. Tissue plasminogen activator
Which vitamin is a cofactor that is important in collagen formation and has antioxidant properties? A. Vitamin B9 B. Vitamin B12 C. Vitamin C D. Vitamin D E. Vitamin K
C. Vitamin C
A 2 year old girl is brought to the emergency department because of pain in her right forearm after a fall one hour ago. She has history of fractures of the left femur and right tibia. Physical examination shows sky blue sclera and an aortic murmur. There is tenderness to palpation over the distal right radius. A mutation in which of the following genes is the most likely cause of the recurrent fractures in this patient?
Collagen Tvpe I Patient has osteogenesis imperfecta Remember: Heart valves have collagen too
A 300 amino acids polypeptide can assume several possible structures. Forming a alpha helix releases 1,520 kcal/mol of energy, forming a Beta sheet releases 4,595 kcal/mol of energy, and forming hydrogen bonds with water releases 823 kcal/mol. This given polypeptide will spontaneously form a: A. Beta turn B. An irregularly structured region C. Beta sheet D. Alpha helix
D. Alpha helix Verify
If the pKA of lactic acid is approximately 4.0, what is the ratio of conjugate base to acid at pH 6.0? A. 100:10 B. 1:1 C. 10:1 D. 100:1 E. 1:10
D. 100:1
If the pKA of lactic acid is approximately 4.0, what is the ratio of conjugate base to acid at pH 3.0? A. 1:1 or 1 B. 1:1000 or 0.0001 C. 100:1 or 100 D. 1:10 or 0.1 E. 1:100 or 0.001
D. 1:10 or 0.1
Slidenafil is an inhibitor of the phosphodiesterase (PDE) enzyme. Which would you expect to be elevated after a treatment with the Slidenafil? A. CAMP B. Ca2+ C. PIP2 D. AMP
D. AMP
Myasthenia gravis (MG) is a neuromuscular disorder due to an autoimmune reaction against the nicotinic acetylcholine receptor. Receptor inactivation impedes muscle cells from contracting under the effect of acetylcholine, producing muscular weakness and fatigue. Treatment consist of acetylcholinesterase inhibitors and immunosuppressants. Which of the following would be affect in MG patients? A. The capacity to increase cAMP production B. Dimerization of receptor tyrosine kinases C. The capacity to increase intracellular Ca2+ D. Activation of ligand gated channels E. The capacity to activate phospholipase C
D. Activation of ligand gated channels Remember Ach receptor is a channel for Na+ and K+ Nicotinic receptors are charged Muscaranic is a G protein couple receptor
A 45-year-old woman comes to your office for a routine examination. You order routine blood and urine tests. The patients blood calcium level appears elevated. Further testing reveals a benign tumor of the parathyroid gland. The patient also shows elevated levels of calcitonin, a 32-amino acids polypeptide hormone involved in the regulation of calcium in the body, and that exerts its effect by binding to a hepatic-helical receptor (a G protein is involved). What signal transduction component do you think would be elevated in this patient? A. A transcription factor with high affinity for hormone-response promoter elements B. A tyrosine kinase C. A cytoplasmic hormone receptor D. Adenylate cyclase E. A voltage-activated channel
D. Adenylate cyclase
Refer to the image below. Which of the following mediates the following reaction labeled as #2? A. Phosphodiesterase B. Protein phosphatase C. GTPase D. Adenylyl Cyclase
D. Adenylyl Cyclase Verify (could be phosphodiesterase too)
The following figure illustrates: A. Proximity and orientation B. Enzyme-substrate complex C. Lock and key model D. All of the above are correct
D. All of the above are correct
A 300 amino acid polypeptide can assume several possible structures. Forming a alpha helix release 1,520 kcal/mol of energy, forming a beta sheet release 4,595 kcal/mol of energy, and forming hydrogen bonds with water release 823 kcal/mol. This given polypeptide will spontaneously form a: A. Beta turn B. An irregularly structure region C. Beta sheet D. Alpha helix
D. Alpha helix
A 7 year old African American male is admitted to the ER with severe abdominal pain. A blood work up indicated anemia and an abnormal blood smear. Which of the following is the molecular event triggering this episode? A. Loss of Hb quaternary structure B. Increase in O2 binding to Hb C. A gain in ionic interactions that stabilized the T state of Hb D. An increase in hydrophobic interactions between T Hb molecules E. An alteration in Hb secondary structure leading to the loss of alpha helices
D. An increase in hydrophobic interactions between T Hb molecules
Trypsin-like proteases are involved in the post-translational processing of many proteins to form biologically active substances. The site of cleavage is determined by the location of two basic amino acid residues next to each other in the protein. Such sites are: A. His-Glu B. Glu-Asp C. Leu-Leu D. Arg-Lys E. Leu-Arg
D. Arg-Lys
A 35 year old HIV positive man is given the protease inhibitor indinavir (Crixivan) as part of his treatment regimen. This inhibitor acts as a competitive inhibitor of the natural substrate for the HIV protease. Which type of protease is the target of such an inhibitor A. Serine proteases B. Metalloproteases C. Thioproteases (Aka cysteine proteases) D. Aspartyl Proteases
D. Aspartyl Proteases
Substances that contain ionic bonds (e.g. NaCl) readily dissociate in water to yield ions. This is because water has a very high: A. Heat of evaporation B. Viscosity C. Surface tension D. Dielectric constant
D. Dielectric constant
Which of the following plasma membrane receptors activate signaling pathways by forming molecular divers that result in protein phosphorylation reactions upon binding of their specific ligand? A. Steroid hormone receptor B. Receptor tyrosine kinase C. Ligand-gated ion channels D. G protein-coupled receptor
D. G protein-coupled receptor
Which of the following is critical for the formation of the hard clot? A. Plasminogen B. Plasmin C. Tissue plasminogen activator D. Glutamine and lysine residues on fibrin E. Factor VII
D. Glutamine and lysine residues on fibrin
Which of the following plays a predominant effect on shaping the overall 3D structure of a globular protein? A. Sulphur bridges B. Hydrogen bonding C. Salt bridges D. Hydrophobic effect E. Steric effects
D. Hydrophobic effect Verify
As a pathologist, you receive breast cancer tumor biopsies from 20 patients, and based on your analysis you need to make a recommendation as to which of these patients will respond to a therapy based on blocking the action of a growth factor receptor. What technique would you use? A. Western Blot B. Enzyme-linked immuno-absorbent assay (ELISA) C. Mass spectroscopy D. Immunohistochemistry E. X-ray crystallography
D. Immunohistochemistry
Cigarette smoking can alter the activity of many types of pharmacotherapy, particularly those drugs that are metabolized by cytochrome enzymes in the lung and liver. Often clinicians need to increase does or dosing regiments in chronic smokers to achieve similar therapeutic effects. Biopsy of lung and liver indicate increased levels of cytochrome P450 enzymes, particularly CYP2E1 and CYP2A1 in lung and CYP1A2 in liver of smokers. What is the mechanism by which cigarette smoking causes this effect? A. Allosterism B. Covalent modification C. Protein-protein interaction D. Induction E. Isoenzyme action
D. Induction
Paracetamol is toxic to liver when converted to a bento-quinone form by cytochrome P450 (cP450) in excess amounts. Normally less than 5% of a therapeutic dose ends up as a benzo-quinone. At this level, hepatotoxicity is avoided by excretion after conjugation with glutathione. HIV patients taking certain antiretrovirals show increased susceptibility to paracetamol. Efavirenz is a NNRTI that does not affect gluthathione, but instead stimulates expression of cP450 effectively increasing the conversion of paracetamol to the benzo-quinone form. This drug-drug interaction is an example of which type of enzyme regulation? A. Covalent modification B. Zymogen activation C. Allosteric interactions D. Induction
D. Induction Because more protein is induced/expressed
A 47 year old male arrives unresponsive at the ER in a state of comma. His wife indicates that he has lately been complaining of fatigue as well as showing signs of polyphagia (frequent hunger), polydipsia (constant thirst) and polyuria (increased volume of urination). His breath has a fruity odor, laboratory test of this patient revealed the presence of acetoacetate (CH3COCH2COO-), pKa = 3.4. A ketone body, in his urine. Which of the following is TRUE about this compound? A. 50% of this compound is present in protonated form at physiological pH B. 100% of this compound is in its deprotoned form at pH 3.4 C. Is produced by carbonic anhydrase D. Is 100% in the form of the conjugate base of weak acid at physiological pH E. Is a component of the blood buffer system
D. Is 100% in the form of the conjugate base of weak acid at physiological pH
Which of the following proteases is NOT correctly paired with its mechanism of catalysis? A. Serine proteases - catalytic triad B. Thioproteases - catalytic triad C. Aspartyl proteases - activated water nucleophile D. Metalloproteases - catalytic triad E. Cysteine proteases - catalytic triad
D. Metalloproteases - catalytic triad
After taking a semester of biochemistry and realizing it is clearly the premier science, you spend a semester doing research in an enzyme lab. You notice that no matter what enzyme you study, when add compound A to any enzyme, you find normal activity at 37 degree Celsius and a complete loss of activity at temperatures above 55 degrees Celsius. What is the type of inhibition you are observing? A. Competitive B. Irreversible C. Non—competitive D. Non-specific
D. Non-specific
The target cells of a lipid soluble hormone such as cortisol, can respond to it because of which of the following? A. Their genome includes the appropriate transcription responses element B. They have membrane bound cell surface receptors C. The hormone-receptor complex stimulates the phosphorylation of subsequent proteins in the signaling pathway D. Only target cells express appropriate cytosolic/nuclear receptors
D. Only target cells express appropriate cytosolic/nuclear receptors
The general name for an enzyme that transfers phosphate group from ATP to a protein is: A. Phosphorylase B. Phosphodiesterase C. ATPase D. Protein kinase
D. Protein kinase
MMPs are important for tissue remodeling during would healing. They break down extracellular matrix at the injury site but would also cause damage to healthy adjacent tissue. Healthy tissue is projected by the presence of a protein that binds to and inactivated MMPs, call tissue inhibitor of metalloproteinase (TIMP). This represents what type of regulation? A. Covalent modification B. Zymogen activation C. Allosteric interactions D. Protein-protein interactions E. Isoenzymes
D. Protein-protein interactions
You are running a lab experiment to study the relationship between substrate concentration and reaction rate. You determine that the velocity of the reaction increases in much faster when you add structure. Subsequent kinetic analysis shows the increase in velocity is exponentially related to the increase in substrate concentration. How would you categorize this enzyme catalyze reaction? A. Simple B. Complex C. First order kinetics D. Second order kinetics
D. Second order kinetics
A 56 year old male uses the drug hydralazine, a smooth muscle relaxant and vasodilator, to treat his hypertension condition. Since he started using hydralazine he has been complaining from joint pain, frequent fevers and frequent skin rashes, all these being symptoms of lupus erythematous. Interestingly, all these symptoms disappeared when the patient stopped talking hydralazine. As the doctor explained to him, a possible cause for these side effects is that oxidants produced in the body reacted with hydralazine converting it into a reactive hydralazine derivative that reacts with a normal protein in the patients body leading to the formation of immune receptive complexes. Which of the following is the antigen in the immune response described above? A. The hydralazine before reacting with oxidants B. The hydralazine derivative (after oxidation) C. The normal protein in the patients body D. The hydralazine derivative complexed with the normal patients protein E. The oxidants in the patients body
D. The hydralazine derivative complexed with the normal patients protein
A 56 year old male uses the drug hydralazine, a smooth muscle relaxant and vasodilator, to treat his hypertension condition. Since he started using hydralazine he has been complaining from joint pain, frequent fevers and frequent skin rashes, all these being symptoms of lupus erythematous. Interestingly, all these symptoms disappeared when the patient stopped talking hydralazine. As the doctor explained to him, a possible cause for these side effects is that oxidants produced in the body reacted with hydralazine converting it into a reactive hydralazine derivative that reacts with a normal protein in the patients body leading to the formation of immune receptive complexes. Which of the following statements pertaining to this case is correct? A. The hydralazine derivative is a haptenic determinant B. The hydralazine derivative by itself is highly immunogenic C. The normal protein in the patients body is a hapten D. The normal protein in the patients body acts as a carrier E. The normal protein in the patients body is highly immunogenic even before reacting with the hydralazine derivative
D. The normal protein in the patients body acts as a carrier
Which of the following amino acid is NOT correctly paired with the functional group/moiety found in its R group? A. Valine - isopropyl group B. Tyrosine - phenol C. Serine - alcohol D. Threonine - carboxylic E. Arginine- guanidino
D. Threonine - carboxylic Verify
Each of the following lipid types is a membrane constituent EXCEPT which one? A. Sphingolipids B. Phospholipids C. Gangliosides D. Triglycerides E. Cholesterol
D. Triglycerides
During the past month, a 37 year old woman has had epigastric pain after eating and at night; she has a feeling of fullness and bloating even when she eats small amounts. For 2 days, she has had repetitive vomiting between meals. Six months ago, she was diagnosed with a peptic ulcer due to gastric reflux and was treated with an inhibitor of the proton pump. After 2 weeks of treatment, her symptoms were alleviated, and she discontinued the medication. This inhibitor likely targets which of the following transports? A. Electrogenic B. Symport C. Simple Diffusion D. Antiport, passive E. Antiport, active
E. Antiport, active
Which factor is active in phase 2 (anti-coagulation) and not phase 1 of hemostasis? A. Tissue factor B. FVIIa C. FXa D. Thrombin E. Antithrombin III
E. Antithrombin III
Which of the following hormones is able to cross the cell membrane? A. Epinephrine B. Norepinephrine C. Insulin D. Glucagon E. Cortisol
E. Cortisol Because epinephrine, norepinephrine, insulin, and glucagon cannot without some type of assistance (verify)
What molecular marker(s) in a patient with potential breast cancer will be most useful to help you establish prognosis? A. Collagen B. Glyceraldehyde dehydrogenase (GAPDH) C. P53 D. Ras E. E-cadherin
E. E-cadherin Not p53 becauseeee?
The transfer of glucose across the plasma membrane into neuron/nerve cells occurs by: A. Simple diffusion B. Facilitated diffusion, insulin-requiring C. Sodium ion co transport D. ATP - dependent active transport E. Facilitated diffusion, insulin-independent
E. Facilitated diffusion, insulin-independent
Which of the following is a characteristic of alpha helices? A. Adjacent amino acids with bulky and branched R groups B. Hydrogen bonding is perpendicular to the peptide backbone C. High Pro and Gly content D. Long segments with adjacent aspartic acid residues E. Hydrogen bonding parallel to the peptide backbone
E. Hydrogen bonding parallel to the peptide backbone
After a first time exposure to ragweed pollen, an initial immune response occurs followed by long term sensitization to recurrent exposures to ragweed. Analysis for antibodies specific for the ragweed pollen would show immunoglobulins of which of the following classes at Initial exposure, Long-term plasma levels, and during Acute allergic response? A. IgG, IgM, IgA B. IgD, IgG, IgA C. IgM, IgA, IgD D. IgG, IgA, IgE E. IgM, IgG, IgE
E. IgM, IgG, IgE
Glucagon causes inactivation of pyruvate kinase in liver but has no effect on pyruvate kinase in muscle. Pyruvate kinase catalyze phosphorylation of PEP to pyruvate in both tissues. What type of regulation is this? A. Covalent modification B. Zymogen activation C. Allosteric interactions D. Protein-protein interactions E. Isoenzymes
E. Isoenzymes
Which of the following will not disrupt hemostasis? A. Factor V Leiden B. Hemophilia A C. Hemophilia B D. Exposure to warfarin E. Low dose aspirin in a healthy person
E. Low dose aspirin in a healthy person
A characteristic of a membrane transport mediated by a pump is: A. Non-specific binding of the solute by the transporter B. Detachment of the transporter from the membrane after transport C. Rate of transport directly proportional to solute concentration D. Release of the solute only if the concentration on the new side is lower than that on the original side E. Undergoes conformational changes
E. Undergoes conformational changes
Which vitamin is a cofactor in a carboxylation reactions and is lipid soluble? A. Vitamin B9 B. Vitamin B12 C. Vitamin C D. Vitamin D E. Vitamin K
E. Vitamin K
With this technique you will be able to determine if a particular mutation affects how a protein is folded: A. Western Blot B. Enzyme-linked immuno-absorbent assay (ELISA) C. Mass spectroscopy D. Immunohistochemistry E. X-ray crystallography
E. X-ray crystallography
What are the main comments of proteoglycans?
GAGs and Core proteins
A 69 year old alcoholic man who lives alone presents for evaluation of a shoulder would that is not healing well. He admits to have poor nutrition. On physical examination, numerous ecchymoses (subcutaneous bleeding spots) are notes on the posterior aspect of his legs and thighs. Careful examination of the mans skin reveals minute hemorrhages around hair follicles, and splinter hemorrhages in the nail beds. Laboratory analysis remarkable for hemoglobin levels of 10 (normal 14-18 g/dL); no other hematologist abnormalities are noted. Which dietary supplement do you think could alleviate his conditions?
He would benefit from Vitamin C If he's an alcoholic he could have a problem with vitamin absorption Patient shows signs of scurvy with markings Blood loss Look up other vitamins he would benefit from
In metabolic alkalosis pH is ____________ (high/low); HCO3- is ____________ (high/low); PaCO2 is _______________
High, High, High
In Respiratory acidosis pH is ____________ (high/low); HCO3- is ____________ (high/low); PaCO2 is _______________
High, Low, Low (verify)
In Respiratory Alkalosis pH is ____________ (high/low); HCO3- is ____________ (high/low); PaCO2 is _______________
Low, High, High
In metabolic acidosis pH is ____________ (high/low); HCO3- is ____________ (high/low); PaCO2 is _______________
Low, Low, Low
A 25 year old woman in her third trimester of pregnancy presents with a 30-minute history of sudden severe abdominal pain and profuse vaginal bleeding. On physical exam, BP is 90/50 mmHg; she has a facial appearance of big eyes, a small chin, and this lips, translucent skin, hyper mobility of joints and 2 bruises on her legs. CT scan imaging shows and enlarged abdominal aorta (aneurysm). This patient has a disorder associated with what element of connective tissue?
Patient has Ehlers Danlos type IV (Vascular Ehlers Danlos) With this syndrome it is most of the time a defect or mutation in the COL3A1 gene (collagen type III) Clinical presentations: Severe blood loss due to ruptured hollow organs or arteries; weakened blood vessel walls
Refers to the spatial relationship of neighboring amino acids: A. Primary B. Secondary C. Tertiary D. Quaternary
Pending (because the answer was E but im like what was E lol)
How does an increase in altitude affect Hb O2 affinity curve?
Shift its to the right
How does a decrease in CO2 affect Hb O2 affinity curve?
Shifts if to the left (verify)
How would a increase in pH affect Hb O2 affinity curve?
Shifts it to the left
How does a increase in CO2 affect Hb O2 affinity curve?
Shifts it to the left (verify)
How does a decrease in pH affect Hb O2 affinity curve?
Shifts it to the right
dielectric constant
Substances that contain ionic bonds (e.g., NaCl) readily dissociate in water to yield ions. This is because water has a very high:
heat of evaporation
Sweating reduces body heat through evaporative cooling. This happens because water has a very high:
What is the effect on hemostasis if there is an issue with Factor 13?
The formation of clots will be prevented
What is the effect on hemostasis if there is an issue with the Von Williebrand Factor
The formation of clots will be prevented Primary hemostasis specifically will be affected
What is the effect on hemostasis if there is an issue with the factor protein C?
The formation of clots will be promoted
Flip card
This graph shows competitive inhibition
Flip card
This graph shows what type of inhibition? NonCompetitive inhibition
A 28 year man presents to the ER with a large amount blood and proteins in the urine (hematuria and proteinuria, respectively) with early signs of kidney failure. He has had sensineueral hearing loss since teen years and has misshaped lenses (anterior lenticonus). Microscopic analysis of a kidney biopsy showed disorganized collagen in the glomerular basement membranes. Which protein would you expect to be defective in this patient?
This patient has Alport syndrome Defect in collagen type IV Can be mutations in the COL4A3, COL4A4, and COL4A5 genes (Compare structure of collagen type I and collagen type IV)
1. Corticotropin (ACTH) 2. Corticotroopin-releasing hormone (CRH) 3. Dopamine ( D1, D2) 4. Epinephrine (Beta-adrenergic) 5. Follicle stimulating hormone (FSH) 6. Glucagon 7. Histamine (H-2) 8. Luteinizing hormone (LH) 9. Melanocyte-stimulating hormone (MSH) 10. Odorants (many) 11. Parathyroid hormone 12. Prostaglandins (E1, E2, (PGE1, PGE2)) 13. Serotonin (5-HT-1alpha, 5-HT-2) 14. Somatostatin 15. Tastants (sweet, bitter) 16. Thyroid-stimulating hormone (TSH)
What signals use the cAMP/PKA signaling pathway
water
Which liquid will have more surface tension, ethanol or water?
D. Threonine-carboxylic
Which of the following amino acids is NOT correctly paired with the functional group/moiety found in its R group? A. Valine-isopropyl group B. Tyrosine-phenol C. Serine-alcohol D. Threonine-carboxylic E. Arginine-guanidino
Both beta-hydroxybutyrate and acetoacetate are ketone bodies, which are produced by the liver under conditions of extended fasting. The two seton bodies are easily interconverted depending on the conditions present within the mitochondria, where they are synthesized.
in progress
The bonds labeled A and B in the compound shown are best described as which one of the following? A. Compound A -Anhydride Compound B-Ester B. Compound
in progress