SAMPLE EXAM ONE QUESTIONS
 

The following is a list of terms that refer to the fifteen definitions below. Choose the term that best fits the definition and write the letter that is next to the term as your answer. Terms can be used more than once. Also, if no term seems correct, write the letter E as your answer. (2 pts. Each)

A.  ionic bond             A. functional group                      A. mitochondria
B.  stereoisomer          B. covalent bond                          B. polymer
C.  Golgi apparatus     C. hydrogen bond                         C. eucaryotic cell
D.  procaryotic cell     D. condensation reaction                D. polar covalent bond
 

1.  Forms when one atom in a bond is more electronegative than the other atom. _____
2.  Organelle that creates most of the cell’s energy. _____
3.  Used by cells to create polypeptides and polysaccharides. _____
4.  Type of cell that has a nucleus. ____
5.  Intermolecular bond that causes ice to be less dense than liquid water.____
6.  Bond that forms between carbon and hydrogen. _____
7.  Type of cell that has organelles. ______
8.  Equal sharing of electrons ______
9.  The organelle that is the site of photosynthesis. ____
10.  Created by sequential condensation reactions. _____
11.  Amino acid _____
12.  Only found in procaryotic cells. _____
13.  Polypeptide or polysaccharide _____
14.  NaCl _____
15.  a steroid ____
 

Statements 16 through 25 are either True or False. If True, answer A, if False, answer B. (2 pts. Each)

16.  Animal fats usually contain fatty acid tails that are unsaturated. ___
17.  The first amino acid in a polypeptide is at the amino terminus . ___
18.  An alpha helix is a type of secondary structure in a polysaccharide. ___
19.  Hydrophobic interactions can occur between amino acids with ionizable side chains. ____
20.  Cellulose is composed of beta-D-glucose monomers. ____
21.  Triglycerides  are made from three fatty acids and three glycerol molecules. ___
22.  Cholesterol is a steroid molecule found in the cell membrane. ____
23.  Cellulose is a structural polysaccharide. ____
24.  Hypotonic solutions make the healthiest plants. ____
25.  The energy for primary active transport comes from ATP. ____

Questions 26 through 50 are multiple choice. Choose the best answer. (2 pts. each)

26. What is the difference between an acid and a base?

A.  An acid undergoes a reversible reaction while a base does not.
B.  An acid releases OH- ions in solution while a base accepts OH- ions.
C.  An acid releases H+ ions in a solution while a base releases OH- ions.
D.  An acid releases OH- ions in a solution while a base releases H+ ions.
E.  An acid releases H+ ion in solution while a base accepts H+ ions.

27. Polar molecules

A.  have an overall negative charge.
B.  have an equal distribution of charge.
C.  have an overall positive charge.
D.  have an unequal distribution of charge.
E.  are ions.
 

28. Two atoms are held together in four covalent bonds because of forces between

A.  electrons and protons.
B.  electrons and electrons.
C.  protons and neutrons.
D.  protons and protons.
E.  neutrons and neutrons.

29. Two carbon atoms held together in a double covalent bond share

A.  one electron.
B.  two electrons.
C.  three electrons.
D.  four electrons.
E.  eight electrons.

30. The functional group written as –COOH

A.  is found in amino acids.
B.  is called a carboxyl group.
C.  designates an organic acid.
D.  B and C  are correct.
E.  A, B, and C are correct.

31. Which of the following is true about protein structure?

A.  All proteins have tertiary structure.
B.  All proteins have secondary structure.
C.  All proteins have primary structure.
D.  All are correct.
E.  None are correct.

32.  What type of amino acid side chain would you expect to be on the surface of a protein that is embedded in the membrane?

A.  cysteine
B.  hydrophobic
C.  polar, uncharged
D.  charged, acidic
E.  charged, basic

33.  What would you expect to happen if you removed a plant cell wall and put the plant in pure water?

A.  The cell would begin to grow.
B.  The cell would shrink.
C.  The cell would burst.
D.  The cell would first swell and then shrink.
E.  The cell would first shrink and then swell.

34.  The interior of the phospholipid bilayer is

A.  hydrophilic.
B.  hydrophobic.
C.  aqueous.
D.  solid.
E.  charged.

35.  In biological membranes, the phopholipids are arranged in

A.  a bilayer with the fatty acid tails pointing toward each other.
B.  a bilayer with the fatty acid tails pointing outward.
C.  a single layer with the phosphate containing region facing the interior of the cell.
D.  a single layer with the fatty acid tails facing the interior of the cell.
E.  a bilayer with the phosphate groups in the interior of the membrane.

36.  In the parietal cells of the stomach, the uptake of chloride ions is coupled to the transport of bicarbonate ions out of the cell. This type of transport system is called

A.  a uniport.
B.  a symport.
C.  primary active transport.
D.  diffusion.
E.  an antiport.

37.  When a red blood cell is placed in an isotonic solution, which of the following will occur?

A.  The cell will shrivel.
B.  The cell will swell and burst.
C.  The cell will shrivel, and then return to normal.
D.  The cell will swell, and then return to normal.
E.  Nothing,  no net change.

38.  Cholesterol molecules act to

A.  help hold a membrane together.
B.  transport ions across membranes.
C.  attach to carbohydrates.
D.  increase the fluidity of the membrane.
E.  disrupt membrane structure.

39.  Osmosis moves water from a region of

A.  high concentration of dissolved material to a region of low concentration.
B.  low concentration of dissolved material to a region of high concentration.
C.  hypertonic solution to a region of hypotonic solution.
D.  negative osmotic potential to a region of positive osmotic potential.
E.  low concentration of water to a region of high concentration of water.

40.  Secondary active transport involves all of the following except

A.  the direct use of ATP.
B.  coupling to another transport system.
C.  use of regained energy from an existing gradient.
D.  the requirement for energy.
E.  the ability to concentrate the transported molecule.

41.  A symport

A.  moves two ions or molecules across the membrane in the same direction sequentially.
B.  moves two ions or molecules across the membrane in opposite directions sequentially.
C.  moves two ions or molecules across the membrane in opposite directions at the same time.
D.  moves two ions or molecules across the membrane in the same direction at the same time.
E.  moves two ions or molecules across the membrane either in the same direction or in the opposite direction, depending upon the concentration gradients.

42. Facilitated diffusion

A.  requires energy.
B.  is highly specific for a particular molecule being transported.
C.  moves molecules only with a favorable concentration gradient.
D.  Only B and C are correct.
E.  all of the above are correct.

43.  Plant cells

A.  have a cell membrane but not a cell wall.
B.  have a cell wall but not a cell membrane.
C.  have both a cell wall and a cell membrane.
D.  are procaryotic cells, therefore they do not have a cell wall.
E.  are procaryotic cells, therefore they do not have any cell membrane.

44.  You place cells in a solution of glucose and measure the rate at which glucose enters the cell. As you increase the concentration of the glucose solution, the rate at which glucose enters the cells increases. However, you reach a point where further increases in the glucose concentration no longer causes the rate to increase. Which of the following is the most likely mechanism for glucose transport into the cell?

A.  simple diffusion
B.  facilitated diffusion
C.  secondary active transport
D.  primary active transport
E.  osmosis

45.  In condensation reactions, the atoms that make up a water molecule are derived from

A.  oxygen.
B.  only one of the reactants.
C.  both of the reactants.
D.  carbohydrates.
E.  ATP

46.  Amino acids are classified by

A.  the number of monosaccharides they contain.
B.  the number of carbon-carbon double bonds in their fatty acids.
C.  the number of peptide bonds they can form.
D.  the number of disulfide bridges they can form.
E.  the characteristics of their side chains.

47.  You fill a shallow pan with water and place a drop of red ink in one end of the pan and a drop of green ink in the other end. Which of the following is true at equilibrium?

A.  The red ink is uniformly distributed in one half of the pan and the green ink  is uniformly distributed in the other half of the pan.
B.  The red and green inks are both uniformly distributed throughout the pan.
C.  Each ink is moving down its concentration gradient.
D.  The concentration of each ink is higher at one end of the pan than at the other end.
E.  No predictions can be made without knowing the molecular weights of the pigment molecules.

48.  The sodium-potassium ATPase

A.  changes its conformation in response to the sodium concentration.
B.  changes its conformation because it receives a phosphate group from ATP.
C.  changes its conformation in response to the potassium concentration.
D.  changes its conformation in response to the ATP concentration.
E.  changes its concentration because of a favorable concentration gradient of a co-transported ion.

49.  Secondary structures of polypeptides

A.  are due to non-covalent interactions between the amino acid side chains.
B.  are stabilized by covalent linkages between the amino acid side chains.
C.  are stabilized by covalent linkages between the peptide bonds.
D.  are stabilized by non-covalent interactions between the peptide bonds.
E.  are stabilized by non-covalent interactions between individual polypeptide subunits.

50.  Glycogen

A.  is a polymer of alpha-glucose monomers.
B.  is a short-term storage form of energy in plants.
C.  has a very elongated, inflexible structure.
D.  is a protein.
E.  all the above are correct.

Also, some questions regarding energy and enzymes from previous tests. (Ignore numbering).
 

26.  End products of biosynthetic pathways often act to block the initial step in that pathway. This phenomenon is called

A.  allosteric activation.
B.  denaturation.
C.  competitive inhibition.
D.  negative feedback.
E.  coupling of reactions.

30.  The enzyme amylase increases the rate at which starch is broken down into smaller oligosaccharides. It does this by

A.  decreasing the change in free energy of the reaction.
B.  increasing the change in free energy of the reaction.
C.  increasing the concentration of the reactants.
D.  decreasing the concentration of  the products.
E.  decreasing the activation energy of the reaction.

31.  In the presence of alcohol dehydrogenase, the rate of reduction of acetaldehyde to ethanol increases as you increase the concentration of  acetaldehyde. Eventually the rate of the reaction reaches a maximum, where further increases in the concentration of acetaldehyde have no effect. Why?

A.  The enzyme is no longer specific for acetaldehyde.
B.  At high concentrations of acetaldehyde, the change in free energy of the reaction decreases.
C.  At high concentrations of acetaldehyde, the activation energy of the reaction decreases.
D.  All of the alcohol dehydrogenase molecules are bound to acetaldehyde molecules.
E.  At high concentration of acetaldehye, the activation energy of the reaction increases.

20.  During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a delta G value of negative 20 kcal/mole. You double the amount of enzyme in the reaction and the delta G value now equals

A.  negative 10 kcal/mole.
B.  negative 20 kcal/mole.
C.  negative 40 kcal/mole.
D.  positive 40 kcal/mole.
E.  It is not possible to calculate this answer with the information given.