PART 1: TRUE OR FALSE (1 Point Each)

Page 16 Code Number ______

PART 1: TRUE OR FALSE (1 point each)

Pick up your number 2 pencil and your scantron sheet and get rolling! Put your NAME, SUID#, and TEST CODE NUMBER on both sides of the scantron immediately. Please bubble in 'A' if the statement is TRUE and 'B' if the statement is FALSE. Remember to be careful when bubbling in your answer. ERASE COMPLETELY.

Both amino acids and sugars are linked into macromolecules via condensation reactions, in which a molecule of water is generated.

In living organisms, the majority of proteins found exist in only one isomeric form.

Within a single protein, both alpha helices and beta sheets can be present.

Noncovalent bonds are the main determinant of protein tertiary structure.

According to the lock and key model of a substrate binding to an enzyme, no confirmational changes in the substrate binding site occur.

If an enzyme's Km is very low, it indicates that the enzyme-substrate binding affinity is very weak.

Two labs measuring the rate of product formation for a reaction, but using different amounts of the same enzyme, will calculate different Vmax values.

Phospholipids spontaneously aggregate into micelle, surface monolayer, or bilayer membrane arrangements.

The nucleus is surrounded by two membrane bilayers.

The nuclear import receptor remains permanently bound to the imported protein after it has passed into the nucleus.

The Golgi apparatus is a site for post-translational protein modification.

Having many intermediates in the oxidation of glucose allows a more efficient transfer of energy than burning glucose in only one step.

All glucose in the bloodstream is immediately broken down after entering the cell, through glycolysis, pyruvate oxidation, the TCA cycle, and oxidative phosphorylation.

Kinesins and dyneins move along microtubules using the energy from hydrolyzing ATP.

Large hydrophilic primary messengers bind to intracellular receptors in order to regulate gene expression.

Acetylcholine can cause opposite effects in different cells.

Primary messengers binding to G-protein-linked receptors never contact the cytosol.

All behavior is a result of external stimuli and reinforcement, thus allowing all behavior to be manipulated and modified.

Male sticklebacks responding to red mail trucks demonstrated the ability of a key stimulus to trigger the fixed action patterns of territoriality.

Vaccines rely on the proper functioning of immunological memory to confer protective immunity on the host.

Heavy chains of immunoglobulins have variable regions, while light chains do not.

PART 2: MATCHING (1 point each)

Answer the following matching questions on your scantron. Remember to choose the BEST answer for each question.

Match the following descriptions with the most appropriate amino acid from the list. Use only one amino acid for each answer. Each amino acid on the list may be used more than once or not at all.

(a) tyrosine

(b) serine

(d) arginine

(e) proline

positively charged
negatively charged
nonpolar
likely to cause "kinks" between protein secondary structures
phosphorylated by PKCs
phosphorylated by the main class of enzyme-linked receptors

Match the following descriptions with the most appropriate cytoskeleton filament.

(a) Intermediate filaments

(b) Microtubules

(d) Equally true of all cytoskeleton filaments

Smallest in diameter (7 nm).
No structural polarity.
Primary filament responsible for movement of cells.
Usually grow from nucleating sites of gamma-tubulin.
Make up the mitotic spindle.
Almost all of its monomer is associated into filaments in the cell.
Made of protein.
Colchicine prevents its polymerization.

Indicate to which branch(es) of the immune system the following statements apply.

(a) Humoral

(b) Cell-mediated

Involves class I MHC molecules.
Involves T-helper cells.
Involves T-cytotoxic cells.
Kills virus-infected self-cells

Match the following immunoglobulins with their most accurate description from the list below. Note: each description can only be used ONCE.

40. IgA (a) In allergic responses, binds to receptors on mast cells.

41. IgD (b) The first serum antibody made in a primary immune response.

42. IgE (c) Endocytosed by placenta and released into fetal circulation.

43. IgG (d) Major antibody in secretions such as saliva, tears, and breast milk.

44. IgM (e) Present on the surface of mature, unprimed B cells.

PART 3: MULTIPLE CHOICE (2 points each)

Move to the second column of your scantron answer sheet and begin bubbling in your answers to these questions in row 51. Remember to choose the BEST answer for each question. Again, be careful when you bubble in your answer. ERASE COMPLETELY.

Which of the following is a normal width range for a eukaryotic cell, for example, a heart cell?

(a) 0.1 nm

(b) 10 nm

(d) 10 µm

(e) 0.1 mm

Which of the following phospholipids is the MOST ABUNDANT in the cell membrane?

(a) Phosphotidylinositol phosphates

(b) Phosphotidylserine

(d) Glycolipids

(e) Phosphotidylethanolamine

Which of the following is NOT a function of the cell membrane?

(a) Exchange of molecules (import/export).

(b) Allow and regulate lateral mobility of proteins.

(d) Signal transduction.

(e) All of the above are functions of the cell membrane.

In an experiment, attaching a nuclear localization sequence (NLS) to keratin results in translocation of keratin into the nucleus. This experiment best demonstrates that the NLS is ______.

(a) Sufficient to cause translocation of a protein into the nucleus.

(b) Necessary to cause translocation of a protein into the nucleus.

(d) Both A and B are demonstrated by this experiment.

Into which of the following organelles does transport of a protein occur while the protein undergoes translation?

(a) Rough Endoplasmic Reticulum

(b) Smooth Endoplasmic Reticulum

(d) Nucleus

(e) Mitochondria

Which of the following is NOT a product of the citric acid cycle?

(a) pyruvate

(b) carbon dioxide

(d) FADH2

(e) GTP

During electron transfer in the respiratory chain, the proton concentration in between the inner and outer membrane of the mitochondria is ______the proton concentration of the mitochondrial matrix.

(a) the same as

(b) higher than

(d) cannot be determined

Which of the following statements about muscle contraction is FALSE?

(a) Muscles are made up of myofibrils, which are made of sarcomeres.

(b) Ion channel-linked receptors are involved in muscle contraction.

(d) Muscle contraction uses oxygen because muscle contraction needs the ATP generated by oxidative phosphorylation.

(e) Mitochondria in muscle cells have more cristae than mitochondria have in other cells.

Tolerance to pain killers in patients with chronic pain can be attributed to what phenomenon?

(a) receptor agonist activity

(b) receptor antagonist activity

(d) allosteric inhibition

(e) A and B only

Which of the following is/are true statement(s) regarding protein phosphorylation?

I. Phosphatases add phosphate groups to amino acids.

II. Phosphate groups can be added only to serine, threonine and tyrosine.

III. Phosphorylation can turn a protein either on or off.

(a) I only

(b) II only

(d) II and III only

(e) I, II and III only

Which of the following is/are true statement(s) regarding Protein Kinase A?

I. cAMP binds to PKA's catalytic subunit leading to its dissociation from the regulatory

subunit.

II. One of the short-term effects of phosphorylation by PKA is the desensitization of

receptors.

III. One of the long-term effects of phosphorylation by PKA is a change in gene

expression.

(a) I only

(b) II only

(d) II and III only

(e) I, II and III only

Which of the following statements regarding imprinting is FALSE:

(a) Occurs during a critical/sensitive time period during development.

(b) Can influence sexual preferences of an imprinted animal later in life.

(d) Auditory imprinting does not occur.

(e) All of the above statements are TRUE statements regarding imprinting.

Which of the following statements about the biological basis of behavior is FALSE?

(a) Changes in hormone levels can alter behavior.

(b) Changes in behavior can alter hormone levels of an animal, in its lifetime.

(d) Behavioral patterns can be inherited.

(e) All of the above are TRUE statements.

PART 4: SHORT ANSWER

Please put away your scantron and take out a black or blue PEN. NO REGRADES will be given for answers written in pencil. Be sure to put your final answers on the lines and inside the boxes for each question. Answers that exceed the allotted space will not be graded.

PROBLEM #1 (15 points)

A. (4 points) The ∆G for the following reaction is +4.5. Draw a free energy diagram for this reaction. Label the ∆G, the activation energy, and the specific reactants and products for the forward reaction.

inositol trisphosphate + diacylglycerol à phosphatidylinositol

[ IP3 + DAG à PIP2 ]

Free Energy

Reaction progress in time

B. (1 point) The enzyme phospholipase C is added to this reaction. Use a DOTTED LINE to depict the altered free energy diagram on the same graph above.

C. (2 points) Phospholipase C (circle one) INCREASES / DECREASES / MAINTAINS the time it takes for the reaction to reach equilibrium, and (circle one) INCREASES / DECREASES / MAINTAINS the equilibrium product to reactant ratio.

D. (1 point) Apa decides she wants to study phospholipase C’s ability to catalyze the formation of IP3. She obtains the following graph:

phosphatidylinositol à inositol trisphosphate + diacylglycerol

[ PIP2 à IP3 + DAG ]

What is phospholipase C's Km? Graphically show your work. ______

E. (2 points) Vivian adds a competitive inhibitor to PIP2 into this reaction. This will (circle one) RAISE / LOWER / MAINTAIN the Km, and (circle one) RAISE / LOWER / MAINTAIN the Vmax of phospholipase C’s enzyme kinetics curve.

F. (2 points) In another series of experiments, Janet adds a noncompetitive inhibitor to PIP2 into this reaction. Use a DOTTED LINE to depict the altered enzyme kinetics curve on the above graph.

G. (2 points) The membrane phospholipid involved in the equation in Part D is depicted below. Label the parts of this phospholipid.

A. ______B. ______

C. ______D. ______

H. (1 point) Label the cytoplasmic and extracellular environments in this picture.

E. ______F. ______

PROBLEM #2 (13 points)

A. (4 points) For each one of the following processes, write on the line where EXACTLY the process occurs. Please be PRECISE.

1. Glycolysis

2. Pyruvate Oxidation

3. Citric Acid Cycle

4. Electron Transport Chain

For each one of the following scenarios place an "X" by the effects which will occur as a result of the problem described.

B. (4 points) Vivian is swimming a 50-meter freestyle in the PAC-10 championships. She is trying to beat her best time of 25 seconds. So, she is moving fast! Place an "X" by the events that will occur in her muscle cells, which are not receiving oxygen.

______glycolysis occurs / ______pyruvate converts to lactic acid
______pyruvate oxidation occurs / ______2 net ATP generated / glucose
______TCA cycle occurs / ______pH in cells decreases
______electron transport chain occurs / ______pH in cells increases
______NAD+ is regenerated during the
electron transport chain / ______acetyl CoA serves as final electron
acceptor
______NADH is regenerated during the
electron transport chain / ______O2 serves as final electron acceptor
______NAD+ is regenerated during lactic acid
formation / ______efficient generation of ATP from
glucose
______NADH is regenerated during lactic
acid formation / ______inefficient generation of ATP from
glucose

C. (3 points) Vivian's friend, Fido, unfortunately is not feeling as energetic as Vivian. Dr. Sohoni has been examining Fido and has discovered that Fido accidentally ate some poison that is inhibiting his ATP synthase. Protons are being blocked from traveling through the synthase. Place an "X" by the immediate events that will occur in his cells.

______glycolysis occurs / ______pyruvate converts to lactic acid
______pyruvate oxidation occurs / ______O2 serves as final electron acceptor
______TCA cycle occurs / ______acetyl CoA serves as final electron
acceptor
______NAD+ regenerates during the electron
transport chain / ______pH in mitochondrial intermembrane
space increases
______NADH regenerates during the electron
transport chain / ______pH in mitochondrial intermembrane
space decreases
______NAD+ regenerates during lactic acid
formation / ______pH in mitochondrial intermembrane
space remains constant

D. (2 points) Fido's friend, Toto, is doing even worse than Fido. Dr. Chinosornvatana examined Toto and discovered that Toto's hexokinase is not functioning properly. Hexokinase is the enzyme that phosphorylates glucose as soon as glucose enters the cell and is the catalyst for the first step of the glycolysis pathway. Place an "X" by the events that will occur in Toto's affected cells.

______glycolysis occurs / ______pyruvate converts to lactic acid
______pyruvate oxidation occurs / ______2 net ATP generated / glucose
______fats broken down to produce ATP / ______proteins broken down to produce ATP
______acetyl CoA serves as final electron
acceptor / ______there will be absolutely no ATP
generated in the cell

PROBLEM #3 (22 points)

A. (8 points) The following flow chart depicts two signaling cascades you have studied. Please fill in the blanks for the sequence of events. BE SPECIFIC.

Signal / Hormone
¯
Receptor
¯
Coupling Protein / G-protein
¯
Effector
¯
Second Messenger Precursor
¯
Second Messenger(s)
¯ / ¯ / Ca2+
Target Enzyme / PKA / PKC

B. (1 point) In the above flow chart, circle the second messenger that is hydrophobic.

C. (1 point) From the above flow chart, the calcium ions listed are released by which organelle?

______

D. (3 points) Low concentrations of primary messengers can produce surprisingly large-scale effects within a cell. Identify two steps within the G-protein-linked receptor pathway in which amplification occurs and briefly explain how.