Which group of proteins protects the body by recognising and binding to foreign antigens?
Correct answer D. Antibodies (immunoglobulins)
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MDCAT ECAT Chemistry MCQs
Page 15 of MDCAT ECAT Chemistry multiple-choice questions with answers. Tap an option to check yourself.
Page 15 of 39
- Gases 40
- Liquids 40
- Solids 40
- Chemical Equilibrium 40
- Reaction Kinetics 40
- Thermochemistry and Energetics 40
- Electrochemistry 40
- Fundamental Concepts of Chemistry 40
- Atomic Structure 39
- Chemical Bonding 39
- Alcohols and Phenols 38
- Industrial Chemistry 37
- Aldehydes and Ketones 37
- Alkyl Halides 37
- s- and p-Block Elements 37
- Chemistry of Hydrocarbons 36
- Fundamental Principles of Organic Chemistry 36
- Carboxylic Acids 36
- Transition Elements 35
- Macromolecules 35
Kwashiorkor, seen in children with swollen abdomens, is caused mainly by a deficiency of ____.
Correct answer A. Protein
How does an enzyme increase the rate of a reaction?
Correct answer D. It provides an alternative pathway with a lower activation energy
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According to the induced-fit model, what happens when a substrate binds to an enzyme?
Correct answer A. The active site changes shape slightly to fit the substrate closely
Why does the activity of most human enzymes fall sharply above about 45 °C?
Correct answer A. The enzyme is denatured and the active site loses its shape
Pepsin, a protein-digesting enzyme in the stomach, has its optimum activity at a pH of about ____.
Correct answer B. 2
How does a competitive inhibitor reduce the rate of an enzyme-catalysed reaction?
Correct answer A. It resembles the substrate and occupies the active site
Which statement describes non-competitive inhibition?
Correct answer D. The inhibitor binds at an allosteric site and alters the active site
An inactive protein part of an enzyme combines with a non-protein cofactor to give the active enzyme. What are these called?
Correct answer B. Apoenzyme + cofactor = holoenzyme
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Urease catalyses the hydrolysis of urea but has no effect on other amides. This illustrates which property of enzymes?
Correct answer D. Specificity
How many peptide bonds are present in a single unbranched polypeptide chain of 120 amino acids?
Correct answer D. 119
How many water molecules are released when four amino acids join to form a linear tetrapeptide?
Correct answer B. 3
Take molar mass of glycine = 75 g/mol, water = 18 g/mol. What is the molar mass of the dipeptide glycylglycine?
Correct answer A. 132 g/mol
How many different linear tripeptides can be made using glycine, alanine and valine, each used exactly once?
Correct answer A. 6
An adult needs about 0.8 g of protein per kg of body mass each day. What is the daily protein requirement of a 65 kg adult?
Correct answer D. 52 g
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Which of the following is a natural adhesive?
Correct answer B. Starch paste
Cyanoacrylate adhesives (super glues) set rapidly because ____.
Correct answer A. Traces of moisture on surfaces start their polymerisation
Epoxy adhesives are supplied as two separate parts. What happens when the resin and the hardener are mixed?
Correct answer D. A cross-linked thermosetting polymer forms
White wood glue, widely used for paper and woodwork, is based on which polymer?
Correct answer A. Polyvinyl acetate (PVA)
A contact adhesive is applied to both surfaces, allowed to become touch-dry and then pressed together. Which polymer is commonly used in such adhesives?
Correct answer A. Polychloroprene (neoprene)