Section I: (22pt total)

1) (A-B) You are given a liter (1L) of a 1.5M NaCl solution (NaCl MW= 58.5).
        A) How would you use that stock solution to make 200ml of a 500mM
        NaCl solution? Include the amounts of all components and the order in
        which you would add them. (3pt)

        B) What % NaCl solution did you just 'make'? (3pt)

2. (A-B) Using both a well labelled graph and text compare the enzymatic activity found the in reaction conditions described below. In each case a standard reaction refers to one performed at 25°C where all necessary components are present and the substrate, coenzyme, and cofactors are all in excess. Graph may be hand-drawn.

        A) Activity in a standard reaction and activity in a reaction where the enzyme amount is dramatically
        increased (rest of components remain in excess). (5pt)

        B) Activity in a standard reaction and activity in a reaction where increasing amounts of a
        competitive inhibitor are added. (5pt)

3. (A-F, 1pt ea.) For each term choose the diagram that contains that structure/ bond. Type the number of the appropriate diagram on your answer sheet.

    A) a-glycosidic bond
    B) cAMP
    C) nucleotide diphosphate
    D) peptide bond
    E) phospholipid
    F) polymer

 (I will insert the diagrams as soon as I get them scanned in)



 BONUS: Two of the structures above were not used. For 0.5 bonus points each, list the number of the structure and its name. (Actual name of compound--not the general type of structure).

Section II: (18pt total)

Short answers: Answer the following questions in a phrase or one or two sentences. (3pt each)

1) What are the 2 major components of biological membranes?

2) What is the difference between active and passive transport?

3) What is voltage?

4) What is an endoplasmic reticulum?

5) Name two methods that separate proteins on the basis of size.

6) What events are triggered by the arrival of the action potential at the synaptic  terminal?


 Section III: (60pt total)

Answer 4 of the following 6 questions. Be careful to answer the question that is asked. Brevity is encouraged. (15pt ea.)

1) Discuss the similarities and differences between the cAMP signaling cascade in liver cells and in myocardial cells. Include steps from initial signal to cellular response. An outline or list format may be used.

2)     A) Discuss, in general terms, why the same signal can cause very different
            responses in different cell types.
       B) List 2 cell types that respond differently to the same extracellular signal.
            (Include the cell types, signal, and responses)
       C) List 2 different cellular responses triggered by the same intracellular
            messenger. (Include the messenger and responses)

3)     A) Why are membrane transporters necessary? Include a discussion of the membrane and the transporters'
       B) In a resting neuron the plasma membrane is approximately 50 times more permeable to K+ than to Na+.
            What does this fact suggest about the relative number of K+ and Na+ transporters in the neuronal plasma
             membrane? (Explain reasoning)
       C) Given the fact that its plasma membrane is permeable to K+ and Na+ how does a neuron maintain its
            resting membrane potential?

4)    A) Briefly describe two examples of mechanisms that cells use to return to their resting state after a signaling
            event has occurred.
       B) Why is the process described in '4A' as important to cell function as initially detecting the signal?

5) Scientific journals rely on a process of 'peer-review' for accepting articles. Authors must allow and respond to critical evaluation of their work before it will be published.
       A) Does the peer-review process support or refute the idea that science is 'self-correcting'? (Explain)
       B) What elements are necessary for science to be 'self-correcting'? (List and explain at least 2)

6) 'Form follows function' is one of the major tenets in the biological sciences.
      A) Explain how a biological membrane is an example of this tenet.
      B) Briefly describe another example of 'form follows function' found at the cellular or sub-cellular level.