nswering each assigned question in 2 to 3 complete, and well written paragraphs is a requirement.This will give your professor a clear view of the concepts, facts, and themes that you understand and what you still need to work on.

You are required to answer each written assignment questions in several (2- 3 or more), well-written, thoughtful paragraphs, IN YOUR OWN WORDS_(new window) If you find it especially difficult to rephrase technical and scientific material, you are not alone. Ask your professor for help.

The questions in the written assignments were purposely created to encourage you to think, make connections, and apply what you have learned. Most of the answers will not be found word for word in the text or the commentaries. This is deliberate – to help you learn to think through and interpret new information. Do your best with them and ask for help if you find yourself stumped or spending unreasonable or unprofitable amounts of time on them. There is very little if anything to be gained educationally from spending inordinate or inappropriate amounts of time on one question or another. Ask your instructor a question any time you find yourself frustrated, panicked, or overwhelmed.

Answering assigned questions in 2 to 3 complete, well written paragraphs will give your instructor a clear view of the concepts, facts, and themes that you are understanding and what you still need to work on. Please review the college’s policy on academic integrity_(new window) and let us know if you have any questions.

Please don’t hesitate to ask a question (click below) about these questions. You may want to read these questions before reading commentaries and the text, as well as afterwards, to highlight what is considered important and what we hope for you to take away.

Questions
Question 1 (5 points)

A. What are the monomers (or subunits) of the following four macromolecules?

complex carbohydrates (polysaccharides)
lipids
proteins
nucleic acids
B. Consider the structure and function of each of these four biological macromolecules.  How does the structure of each molecule affect its function?  For example, in complex carbohydrates, why would long chains of glucose be more effective for energy storage than single glucose molecules? How do the four levels of protein structure affect the shape of enzymes and why is this important for enzyme function? Explain the “lock and key” model of enzyme function using the terms substrate, active site, and product.

Question 2 (5 points)

The chemical formula for the complex carbohydrate glycogen is C24H42O21.

a. What are the elements in glycogen?

b. How many atoms are in one molecule of glycogen?

c. Is glycogen an ion? Why or why not?

d. Is glycogen a monosaccharide or a polysaccharide? Besides memorizing this fact, how would you know this based on the information in the question?

e. What is the function of glycogen in the human body?

Question 3 (5 points)

Pepsin is an enzyme in the stomach that helps us digest protein. Answer the following questions about pepsin.

a. What is the substrate for pepsin?

b. How does pepsin work to speed up protein digestion?

c. Given what you know about the structure of proteins, what do you think are some of the products of the reaction that pepsin catalyzes?

d. The stomach is normally acidic. What do you think would happen to the activity of pepsin and protein digestion if the pH is raised significantly?

Question 4 (5 points)
Neurons are cells in the nervous system that transmit messages. They use energy to maintain the balance of sodium and potassium ions inside and outside of them, which is critical for their ability to send messages.

a. What kind of transport is this maintenance of sodium and potassium ion concentrations: active or passive? Explain your reasoning.

b. What creates the barrier between the inside and the outside of these cells?

c. What molecule uses energy to maintain the balance of sodium and potassium ions inside and outside of neurons? Describe two reasons why a molecule like this is required.

d. What form of energy is used in this process?

e. Briefly explain how the energy in the food you eat gets there, and how it provides energy for your neurons in the form necessary to power this process.