Biology 107 (Dr. Harrington) Problem set 1

BIOL 107 B2 - Problem set 1

My problem set questions fall into one of three categories: organization (better ways to organize your notes), exam (questions that have been or could be on an exam), and thinking (questions that go beyond the course material). I will provide answers to most of the questions but not all. I would be happy to check your answers to the remaining questions of course.

Lecture 1 Macromolecules

Question 1 (organization) Make a table listing the various characteristics of each of the four classes of macromolecules. Your table could include (i) building blocks, (ii) elemental composition, (iii) functions, (iv) examples, and so on.

Question 2 (exam) Why does our digestive enzyme Amylase break down starch but not cellulose?

A. starch is a polymer of glucose; cellulose is made of other sugars
B. cellulose molecules are much too large
C. the sugars in cellulose bond together differently than in starch
D. the enzyme cannot attack cellulose because of its helical shape
E. the bonds between sugars in cellulose are much stronger

Question 3 (thinking) Peanut butter and margarine are made from plant oils and yet both are semi-solid at room temperature. What must occur during the manufacturing of these products?

Question 4 (exam) A peptide bond in a protein connects a _____ to a _____. (Hint: draw it)

A. carbon ... carbon
B. carbon ... oxygen
C. carbon ... nitrogen
D. nitrogen ... oxygen
E. nitrogen ... nitrogen

Question 5 (exam) A molecule that contains only carbon, hydrogen, and oxygen may be a:

A. lipid
B. sugar
C. protein
D. lipid or a sugar
E. lipid, sugar, or a protein

Question 6 (thinking) Carbohydrates are commonly used in cooking. For example dextrose is the common name for glucose, table sugar is crystalline sucrose, molasses is concentrated sucrose, and icing sugar is powdered sucrose.

a) Corn syrup (great on pancakes) is a solution of glucose made from corn starch. By what steps can corn starch be converted into corn syrup?

b) Glucose-fructose (known as high fructose corn syrup or HFCS in the US) is a commonly used sweetener found in pop, candy, etc. It is a mixture of about half glucose and half fructose that is also made from corn starch. How is it made?

c) Honey is a mixture of glucose and fructose that bees make using nectar (~sucrose) from flowers. How is it made?

Question 7 (exam) Which of the following structures is NOT a carbohydrate?

Question 8 (exam) Which of these is the structure of aspartic acid (an acidic amino acid)?

Question 9 (thinking) People, like other animals, use lipids for most energy storage. This is because lipids store six times as much energy per kg as carbohydrates do. Only a small, though significant, proportion of our body's energy is stored as glycogen. Hypothetically, if a person was to use glycogen exclusively they would have to be much larger in order to store the same amount of energy. How much heavier would the person be? Assume this individual is 60 kg and has 20% body fat*. (*For the purposes of this question disregard the fact that only some of our fat tissues are actual fat molecules.)