Biology 111 Unit 1 review This review must be signed in at my office (Wat 289) BEFORE noon on Monday February 12th. Refer to the syllabus for information about course policies regarding tests and other written assignments. • There is no time limit for taking the review except for the final due time. It was designed to be able to be completed in 2 hours and I suggest you use that time as a guideline. To dissuade procrastinators and all-nighters you MUST BEGIN the review before 10pm Sunday. Remember to leave time to print and deliver because it isn’t ‘done’ until it is turned in. • This is a closed-book, closed-note review. Once you have seen any question your review period has begun and you may not talk, listen, read or use other forms of communication to discuss this course. • This page must be the first page of your answer packet. Fill out this page and attach it to the ones containing your answers. The top of each additional page in the packet should contain only your initials and the page number. • All answers must be typed and in complete sentences unless otherwise indicated. Any accompanying graphs or figures may be hand-drawn. • If a question lists a maximum number of words you must include your response’s word count (Microsoft Word/Tools/word count will calculate it for you) • You may use a calculator for +,-,*,and / only. (no preprogramming) To receive full credit all calculations must be included. Calculations/equations may be hand written and do not need to be sentence form. The answer to the question that required the calculation should be in sentence form. • Be sure to completely answer the question asked. Brevity is encouraged. • There are 22 questions worth 100pt and 2 bonus questions worth 4pt. Name: ____________________________________ (PRINT) Signature: _________________________________ Write out the honor code (found here: http://www.davidson.edu/administrative/admission/whydav/honor.html, ‘On my honor…”) ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ _____________________________________________________________ This review was begun at _______ on ________ and completed in ________hours Time DayBiology 111 Unit 1 review Carefully read the information given. The questions refer to this background information and it’s connections with the material covered in Unit 1 and the first three weeks of lab. In our first unit we have seen calcium used as a second messenger. Two of the tools that scientists have used to study calcium’s role as a second messenger are compounds called chelators and ionophores. A chelator is a compound that binds very tightly to an ion. Therefore, a calcium chelator like EGTA, is a compound that binds very tightly to calcium ions. Ionophores are compounds that shuttle ions across membranes. Therefore, ionomycin, a calcium ionophore binds and shuttles calcium across membranes. Structure of EGTA; MW 468.3g Structure of ionomycin; MW 747.1g 1. What are second messengers? (not a list of examples, a definition of the term) (3pt) 2. Briefly describe three different examples of calcium being used as a second messenger that we covered in Unit I. Your answer should be in the form of ‘Calcium is a second messenger in _____ cells where it _____ to result in/cause/promote/inhibit ______. It is also…..’ (100 words max.) (6pt) 3. Name two additional examples of molecules used as second messengers. Discuss similarities between calcium and those two additional examples and explain how those similarities help to make the molecules effective messengers. (5pt) (hypothetical organism) Researchers have recently identified a new multicellular eukaryotic organism and have already determined that it has muscle cells and secretes acetylcholine. You are interested in studying the mechanisms controlling muscle contraction in this new animal. To do so you decide to isolate muscle cells, put them in a buffer that resembles extracellular fluid (so they will live) and examine the effects of acetylcholine and of EGTA.Biology 111 Unit 1 review As stocks you have 5ml of 60mM EGTA; 1ml of 1ng/ml acetylcholine, 50ml of H20 and all of the balances, tubes, slides and equipment found in a standard laboratory. You expose the muscle cells to the following conditions for 5min and then view them under the microscope. You include a scale diagram of the cells you saw in your notebook. All assays include buffer to bring them to a final volume of 200µl. Assay 60mM EGTA 1ng/ml acetyl-choline Representative cell Assay 60mM EGTA 1ng/ml acetyl-choline Iono-mycin 1 10µl 3µl 5 10µl 3µl 2µl 2 0µl 3µl 6 0µl 3µl 2µl 3 10µl 0µl 7 10µl 0µl 2µl 4 0µl 0µl 8 0µl 0µl 2µl For questions 11 and 12 4. What is the molar concentration of EGTA in assay #1? (3pt) 5. What is the concentration of EGTA in assay #1 in % w/v ? (3pt) 6. Acetylcholine binds muscle cells through non-covalent interactions. Explain why this type of interaction between acetylcholine and the cell is important in correct muscle function. ( 4pt) 7. With what type of muscle cell macromolecule does acetylcholine interact? (2pt) 8. Of the four types of biological macromolecules that we have discussed—which type does not form covalently bonded polymers? What type of bonds does this macromolecule form between multiple copies and why is the non-covalent nature important to the roles that macromolecule plays in the cell. (It may help to define polymer and discuss what the cell would or would not be able to do if this macromolecule did form covalently bonded polymers) (5pt) Bonus: Name and draw the monomeric form of one of the four major types of biological macromolecules. (2pt)Biology 111 Unit 1 review 9. Consider the scale images of cells in the table above. Briefly describe what happened in assay #2 that made that cell look the way it does. (50word max—looking for general not details) 4pt 10. Propose an explanation for why including EGTA in the assays has the effect it does. In your response include what EGTA is, and aspects of its chemical structure and the structure of the muscle cell it interacts with that could explain the effect seen. (4pt) In a second