IMAT Biology questions

Sample Biology practice questions

1. 1The role of enzymes · IMAT Doutor

   A competitive inhibitor binds reversibly to the active site of an enzyme. Compared with the uninhibited reaction, it:
   1. Alowers Vmax and leaves the apparent Km unchanged
   2. Braises the apparent Km and leaves Vmax unchanged
   3. Clowers both Vmax and the apparent Km
   4. Draises Vmax and lowers the apparent Km
   5. Echanges neither Vmax nor the apparent Km
   Show answer

2. 2Structure and function of the cell membrane · IMAT Doutor

   What is the role of cholesterol in the plasma membrane of an animal cell?
   1. AIt forms the main structural layer of the membrane, in place of the phospholipids
   2. BIt makes the membrane freely permeable to ions by creating gaps between the phospholipids
   3. CIt buffers fluidity, restraining movement at high temperature and preventing tight packing at low temperature
   4. DIt anchors ribosomes to the cytoplasmic face of the membrane, so that proteins are inserted into the bilayer as they are made
   5. EIt carries the sugar chains of the glycocalyx and takes part in cell-to-cell recognition
   Show answer

3. 3Structure of DNA and RNA · IMAT Doutor

   In a sample of double-stranded DNA, adenine accounts for 30% of the bases. What percentage is guanine?
   1. A30%
   2. B40%
   3. C15%
   4. D20%
   5. E70%
   Show answer

4. 4ATP and bioenergetics · IMAT Doutor

   During the complete aerobic oxidation of one molecule of glucose, how many molecules of carbon dioxide are released?
   1. A2
   2. B3
   3. C4
   4. D6
   5. E12
   Show answer

5. 5Cellular structures · IMAT Doutor

   Which enzyme, characteristic of peroxisomes, protects the cell from hydrogen peroxide?
   1. ACatalase
   2. BAmylase
   3. CHelicase
   4. DATP synthase
   5. EDNA polymerase
   Show answer