HONORS BIOCHEMISTRY FINAL EXAM STUDY GUIDE DR. GOLDIN 2012-2013

Use the following practice questions to help you prepare for our final exam. These questions DO NOT cover ALL of the content that you may be expected to know for the final exam; rather they represent a series of the types of questions you might be expected to answer.

As always, use your UNIT STUDY GUIDES, ONLINE REVIEW GAMES, ONLINE NOTES DOCUMENTS and your BIOCHEMISTRY JOURNAL to review the full range of information and skills that you may be expected to display on the final exam.

YOU SHOULD REVIEW ALL EXPERIMENTS WE HAVE PERFORMED AS DESCRIBED IN YOUR BIOCHEMISTRY JOURNAL; INCLUDING THE DIFFUSION OF DYES THROUGH A MEMBRANE LAB, THE OSMOSIS LAB, THE CIRCUIT DESIGN LAB, THE DAPHNIA MAGNA LD50 LAB, and THE CELL SERV KIT #3 LAB (Observing the Effects of Toxic Chemicals on Cells).

BE PREPARED TO ANALYZE A DESCRIBED EXPERIMENT, INCLUDING EVLAUTING THE PURPOSE OF THE EXPERIMENT, IDENTIFYING THE INDEPENDENT VARIABLE AND DEPENDENT VARIABLES, AN ANALYSIS OF THE VALIDITY OF A GIVEN PROCEDURE, AND INTERPRETATION OF ANY DATA. See, for example the POSTER RUBRIC from THE DAPHNIA MAGNA LD50 LAB….

UNIT III: Consciousness and Personality

Neurons and the Nerve Impulse

1. a) Identify the structural and functional components of a typical neuron. Using the WORD BANK provided, label the structures of the neuron below (see pages 452-453).

WORD BANK: axon axon endings cell body dendrites node of Ranvier nucleus Schwann cell/myelin sheath

b) With reference to the figure above, describe the structure and function of a typical neuron. In your response, include and explain all of the terms from the WORD BANK above (see pages 452-453).

2. Explain what is meant by saying that the plasma membrane is “selectively permeable.” Evaluate HOW/WHY the characteristic of selective permeability is essential to the function of the plasma membrane (see pp. 437-440).

3. Explain what is meant by describing the plasma membrane as a “fluid mosaic.” Evaluate HOW/WHY this organization is essential to the function of the plasma membrane (see page 437-438).

4. a) Using the WORD BANK, label the figure below to identify the basic structure of the plasma membrane (see pp. 755-756 and pp. 438-439).

WORD BANK: fatty acid tail hydrophilic hydrophobic lipid bilayer phosphate group phospholipid

b) With reference to the figure above, explain WHY phospholipids can spontaneously assemble into a lipid bilayer. In your response, include and explain all of the terms from the WORD BANK above.

5. a) Define and explain the phenomenon of diffusion. b) Describe TWO characteristics of a molecule that determine whether it can or cannot diffuse through the plasma membrane. c) Then list specific examples of molecules that can and cannot diffuse through the plasma membrane. (See your Diffusion of Dyes Through a Membrane Lab and p. 439.)

6. a) Define and explain the phenomenon of osmosis. b) Define and explain the terms hypertonic, isotonic, and hypotonic. c) Predict and describe the effect on a cell of being placed in a hypertonic, isotonic, or hypotonic solution. (See your Osmosis Lab and pp. 441-442, especially Figure 14.6 on page 442.)

7. Compare and contrast simple diffusion and active transport. In your answer, define and explain each term and provide a specific example of each (see pp. 439-444).

8. With reference to the provided figure, explain HOW the sodium-potassium pump employs active transport to create concentration gradients and a charge gradient across the plasma membrane of a neuron (pp. 443-445).

The ___________________________

is _____________________________

The ___________________________

is _____________________________

containing

9. With reference to the provided figure, explain HOW the regulated movement of sodium ions (Na+) and potassium ions (K+) across the plasma membrane of a neuron transmits an electrical signal in the form of an action potential. In your explanation include and define all of the terms shown in the figure. (See pp. 453-456)

10. a) Identify the structural and functional components of a neuronal synapse. Using the WORD BANK provided, label the structures of the neuronal synapse below (see pp. 456-462, especially page 461).

WORD BANK:

axon

Ca2+ (calcium ion)

ligand-gated ion channels

neurotransmitter

presynaptic cell

presynaptic membrane

postsynaptic cell

postsynaptic membrane

synaptic cleft

synaptic vesicle

voltage-gated Ca2+ channel

b) Using the terms from the labeled figure, describe the structure and function of a neuronal synapse (pp. 456-462).

11. Using the figure below, explain HOW a neurotransmitter communicates across a synapse and is then recycled (pp. 456-462). In your answer, explain WHY a given neurotransmitter will affect some neurons, but not others.

12. Compare and contrast the electrical signal of the action potential within a neuron and the chemical signal of neurotransmitters between neurons. How are they alike? How are they different?

13. Describe and compare the role of each of the following membrane proteins in the generation of an electrical signal within a neuron versus the chemical signals between neurons: a) Sodium-potassium pump b) Voltage-gated sodium (Na+) channel c) Voltage-gated potassium (K+) channel d) Voltage-gated calcium (Ca2+) channel e) Ligand-dependent ion channel

Electrochemistry

14. a) Draw a diagram of a simple series circuit. In your diagram, be sure to include a power supply, a switch, at least one resistor, and a load (see pp. 535-537 and pp. 541-453). b) Label your diagram to indicate the following: anode, battery, cathode, current/direction of electron (e-) flow, load, resistor, switch, and wire. c) Add labels to show which components are measured in the following units: amps, ohms, volts, and watts. d) Describe the function of each part of your diagram. Explain HOW the parts function together to generate an electric current that gives power to the load of the circuit. e) Compare and contrast what is meant by the terms “closed circuit” versus “open circuit.”

15. Provide a mathematical formula that shows the relationship between voltage, current, and resistance (OHMS LAW!!!). Identify the UNITS in which each component of the formula is measured (see pp. 537-538).

16. Provide a mathematical formula that explains how electric power is calculated. Identify the UNITS in which each component of the formula is measured (see p. 541).

17. For each of the changes to a circuit described below, explain the effect on resistance, the effect on current, and the effect on power to the load.

a) The wire of the circuit is made longer.

b) The wire of the circuit is made shorter.

c) The wire of the circuit is made wider.

d) The wire of the circuit is made narrower.

18. Complete the following Ohm’s Law and Electric Power PRACTICE PROBLEMS. When you are finished check your work against questions 13-18 of the online self quiz at http://www.saaphysics.com/CurrentsPracticeQuiz.htm

a) (13) What is the resistance of a device if the current through it is 10 amps and the voltage across it is 5 volts.

b) (14) If a device is plugged into a 110-V power source and has a resistance of 100 ohms, what is the current through it?

c) (15) How much power is used when a 3 V battery produces 0.1 amp of current?

d) (16) How much power is used by a 9-V battery that produces a 3 amp current?

e) (17) What power is used if a resistance of 100 ohms has a current of 0.1 amps flowing through it?

f) (18) What is the power used in a device if the resistance is 100 ohms and the voltage across it is 4V?

UNIT IV: Drugs and Poisons

Poisons, Pollutants, and Drugs

19. Evaluate: What is a poison? How do we know if a particular chemical is a poison? In your answer explain the terms toxicity, dose, exposure¸ response, and bioassay (see “Assessing Toxic Risk” pp. 3-5).

20. Most hazardous substances exhibit a “dose-response relationship.” Evaluate and explain what this statement means (see Assessing Toxic Risk pp. 3-9).

21. With reference to the figure below, explain HOW the LD50 of a toxic chemical is determined and what it means. What does a low LD50 tell you? A high LD50? (See “Assessing Toxic Risk” pp. 5-9.)

22. Evaluate: By what means can one be exposed to a toxic chemical? Why does the route of exposure matter? In your answer define the terms oral exposure, dermal exposure, and inhalation, and then compare and contrast these three major routes of exposure. (See “Assessing Toxic Risk” pp. 3-5.)

23. The data table to the right provides examples of LD50 values for seven different pesticides. a) List the pesticides in order of ORAL toxicity, from the LEAST toxic to the MOST toxic. b) List the pesticides in order of DERMAL toxicity, from the LEAST toxic to the MOST toxic.

24. A family home has a clogged furnace that is producing carbon monoxide, a hazardous gas. Which family member is likely to be harmed the most and WHY? a) Mr. Nguyen, the father who works from home. b) Mrs. Nyugen, the mother who works at the University. c) Baby Shae, who is going to be in pre-school next year. d) Billy the son who is in 1st grade. e) Karla, the nanny who cares for baby Shae every weekday morning.

25. With reference to the figure below, compare and contrast the ED50, TD50, and LD50 of a drug. HOW is each determined? What does each mean? Which is usually lowest? Which is usually highest? (see “Assessing Toxic Risk” pp. 5-11 and the NOTES document “Drugs, poisons, and toxicity”)

26. With reference to the figure to the right, explain HOW the therapeutic index (TI) of a drug is calculated and what it means. (See “Assessing Toxic Risk” pp. 5-11 and the NOTES for “Drugs, poisons, and toxicity.”)

a) In your response explain the terms therapeutic effect, ED50, toxic effect, TD50, and therapeutic index (TI).

b) Explain the formula by which the TI is calculated.

c) What does a low TI tell you? A high TI? d) What factors other than TI must be

considered when evaluating the efficacy and safety of a drug?

27. Describe, compare, and evaluate: Where might pollutants be found? How does the location of a pollutant

impact its relative risk? WHY?

28. Evaluate and describe: What factors must be considered when evaluating the relative risk of exposure to a given pollutant? WHY?

Cellular Respiration and Toxins

29. a) Provide a balanced chemical equation for cellular respiration (see page 564). b) What are the starting products (reactants) of cellular respiration? c) What are the end products of cellular respiration?

30. With reference to the figure below, explain: a) HOW is a molecule of ATP formed from a molecule of ADP? b) HOW does a change from ATP to ADP provide an organism with energy? c) ATP is an energy carrier. Where is the energy actually located? d) In a eukaryotic cell, where is the majority of ATP manufactured?

ENERGY!!!

31.

32.

TD50 ED50

3 2 1

2 1

33. Analyze the diagram of the Electron Transport Chain of cellular respiration shown below. Explain how the electron transport chain functions to generate ATP. Include the following terms in your answer: inner compartment, outer compartment, inner membrane, NADH, NAD+, hydrogen ion (H+), oxygen (O2), water (H20), electron transport chain, final electron acceptor, ADP, ATP, and ATP synthase (p. 572).

34. NADH and FADH2 are alternate energy carriers. What “energy” are they actually carrying? From where? To where? WHY?

35. Describe the path electrons (e-) follow during cellular respiration, as they travel “downhill,” moving from higher energy states to progressively lower energy states. Where do they originally come from? Where do they finally end up? How do they travel from their starting point to their ending point?

36. a) Describe the role of oxygen in the electron transport chain. b) Predict what would happen to the electron transport chain if oxygen was not present. c) Explain WHY oxygen deprivation has such profound consequences for complex multicellular eukaryotic organisms (like us!)

37. a) Describe the series of energy transformations achieved by the electron transport chain. In your answer define and explain the examples of chemical energy, potential energy, and kinetic energy. b) Explain: what is the most direct source of energy that is used to convert ADP and Pi (inorganic phosphate) into ATP? What structure is responsible for this final energy transformation?

38. With reference to the figure below, describe and explain the mechanisms by which poisons may interfere with the electron transport chain and relate these mechanisms to the poisons toxic effects. Include the following terms in your answer: rotenone, cyanide, carbon monoxide, dinitrophenol (DNP), and oligomycin (p. 573).

Outer

Compart-

ment

Inner

membrane

Inner

Compart-

ment