ALL MCQS 2 Flashcards
Which of the following statements about Metformin is INCORRECT?
D. Metformin promotes gluconeogenesis in the liver.
Metformin actually inhibits gluconeogenesis in the liver, which helps in lowering blood glucose levels in diabetic patients.
In ethanol metabolism, acetaldehyde is converted into acetate by:
B. aldehyde dehydrogenase.
Aldehyde dehydrogenase converts acetaldehyde to acetate during alcohol metabolism.
Which one of the following statements about the consequences of alcohol metabolism is INCORRECT?
C. An increased NADH to NAD+ ratio accelerates the citric acid cycle.
In fact, an increased NADH to NAD+ ratio inhibits the citric acid cycle.
Which statement about Type II diabetes is INCORRECT?
D. Type II diabetes can be treated by taking insulin tablets.
Insulin is typically administered through injections, not tablets, because insulin is a protein that would be digested if taken orally.
Which statement about ketone bodies is CORRECT?
A. They are able to supply the brain with a source of acetyl-CoA.
Ketone bodies are used as an energy source by the brain during fasting.
Which of the following is NOT a biochemical response to exercise?
C. Inhibition of AMP Kinase.
AMP Kinase is activated, not inhibited, in response to exercise to promote energy production.
Which statement about metabolism during anaerobic exercise is INCORRECT?
B. An increased amount of acetyl-CoA is produced from β-oxidation.
β-oxidation primarily occurs during aerobic conditions, not anaerobic.
Which of the following is associated with the development of obesity?
C. Dysregulation of appetite control due to leptin resistance in the hypothalamus.
Leptin resistance in the brain contributes to overeating and weight gain.
In an experiment, 4 mL of solution X was mixed with 12 mL of water. The concentration of the diluted solution is 20 mM. What was the concentration of undiluted solution X?
C. 80 mM.
The dilution factor is 4 mL to 16 mL (total), so the concentration of the original solution is 80 mM.
In an experiment, 6 mL of solution Z was mixed with 18 mL of water. The concentration of the diluted solution is 40 mM. What was the concentration of undiluted solution Z?
C. 160 mM.
The dilution factor is 6 mL to 24 mL (total), so the concentration of the original solution is 160 mM.
To convert g/L to g/mL, you would:
B. divide by 1000.
Why would a decrease in pH from about pH 7 to pH 1 result in the salivary amylase enzyme becoming inactive?
A. Ionisable amino acid side chains of the salivary amylase protein will be protonated, resulting in unfolding (denaturing) of the enzyme.
Which statement about the molar absorbance coefficient (ε) is INCORRECT?
C. It is proportional to the concentration of the solution.
What would you expect to happen if the yeast-treated haemoglobin was shaken vigorously?
A. The absorbance returns to approximately 0.57 and the colour returns to bright red because the effect of yeast is reversible.
Which one of the following is NOT a principle of spectrophotometry?
C. The molar absorbance co-efficient is dependent on the concentration of the absorbing solute.
In spectrophotometry, Beer’s Law indicates that, at a particular wavelength, the absorbance of light through an absorbing solution is proportional to:
B. the concentration of the solution.
How could this dilution have been carried out (for enzyme dilution)?
A. 5 μL enzyme + 50 μL buffer.
Which ONE of the following would be the BEST for measuring specific molecules in complex solutions?
D. Using specific enzyme assays.
What assumption is made to allow for the calculation of cholesterol levels using the formula in the assay?
D. There is a linear relationship between cholesterol concentration and absorbance.
How would you calculate the concentration of cholesterol in the plasma sample?
B. 0.693 ÷ 0.548 x 1.5.
Whether the cholesterol assay performed in lab 5 obeys Beer’s Law can be determined by?
A. Constructing a standard curve for the assay.
Which one of the following statements about the cholesterol assay reaction is INCORRECT?
D. The enzymes are regulated by cholesterol, therefore the cholesterol concentration in the sample will influence the activity of the enzymes, from which the cholesterol concentrations can be calculated.
DNA gel electrophoresis separates molecules primarily based on:
D. size.
The standard curve was used to:
C. use a standard with a known HbA1c to allow the amount of HbA1c in the patient sample to be calculated.
