SC 135 - Second Exam 1997

On the line to the left, place the letter of the choice that best answers the question.
NOTE: "e" answers are never the correct answer. Five Points Each.

1. Kool Aid mix is sugar and flavor crystals that dissolve in water. In a glass of Kool Aid, 
                        the flavor crystals are

__________   a. Solvent                 b. Solute                 c. Solution
                            d. Gradient                     e. Unlike any natural material

2. The pH of the digestive juices within the human small intestine is between 7.5 and 8.5. 
                        This environment could be described as

__________   a. Acidic                     b. Neutral                     c. Basic
                            d. Dehydrated                             e. Icky

3. Which one is a basic cell membrane molecule?

__________    a. Nucleic Acid                     b. Phospholipid                    c. Ribosome 
                        d. Pinocytosis                           e. Cells are too embarrassed to tell

4. Steroid hormones belong to which class of organic molecule?

__________     a. Lipids                     b. Proteins                     c. Carbohydrates
                              d. Nucleic Acids                     e. Pumped-up molecules

5. When atoms stay together due to powerful attractions between opposite charges, the 
                                molecules contain

________       a. Covalent bonds                 b. Ionic bonds                c. Isotopic bonds 
                       d. Enzyme bonds                e. All of the elements of a good romance novel

6. Someone who is lactose intolerant lacks lactase, which is a(n)

________         a. Lipid                     b. Nucleic acid                    c. Sugar 
                         d. Enzyme                    e. I have no time for people who are intolerant

7. The digestion or molecular breakdown of food involves which chemical process?

________         a. Dehydration synthesis             b. Spontaneous generation
                              c. Hydrolysis                              d. Endosymbiosis
                                e. Whatever weird stuff happens in barbeque sauce

8. Glucose molecules leave your blood, where they are in higher concentrations, and 
                    enter your lower-concentration cells by attaching to special carrier proteins.  
                    This process is called

__________   a. Passive transport             b. Osmotic exchange        c. Active transport 
                       d. Insulin transfusion                    e. Gettin' down with sugar central

9. The codons in DNA stand for the

__________   a. Bases in RNA         b. Amino acids in proteins         c. Rings in sugars
                            d. Bases in proteins                 e. Tragedy of man against baldness

10. Where are you most likely to find a chromosome with a loop structure?

__________    a. Dividing plant cell                         b. A cell with ribosomes
                             c. Dividing animal cell                       d. A bacterial cell
                                    e. The whole question seems pretty loopy to me!

11. An atom that has added or lost electrons in order to be more chemically stable:

________     a. Isotope                     b. Acid                     c. Base
                         d. Ion                                     e. Obsessed with appearance

12. Which cell element is most involved in cell movement?

__________     a. Microtubules                 b. Nucleolus                c. Vacuoles 
                         d. Microfilaments                        e. Incredibly tiny moving vans

13. As cells get bigger, the ratio between volume and surface area

__________    a. Rises - volume increases faster than surface area with growth
                        b. Falls - surface area increases faster than volume with growth
                             c. Does not change - they increase proportionately
                             d. All of these
                             e. Oh no! A disguised math problem!!

SHORT ANSWER.  

Answer any ten of the following questions for 7 Points Each.
Note: if you answer more than ten, only the first ten will be corrected.

1. Show the basic reaction, including all molecule and energy types, for photosynthesis.

2. Show the basic reaction, including all molecule and energy types, for aerobic respiration.

3. Lipid molecules are constructed from two basic parts. What are these molecule subunits?

4. Give the common names of the two basic forms of carbohydrates:

Simple:

Complex:

5. Name two organelles that probably began long ago as endosymbionts.

6. What are two different uses for protein molecules?

7. What exactly makes a molecule polar? (Not necessarily bipolar!)

8. The fluid mosaic model describes a cell membrane. Explain:

In what way is the membrane fluid?

In what way is the membrane a mosaic?

9. Name two different types of biological macromolecules.

10. By the newest definition, what features must a molecule have to be considered organic?

11. What does a ribosome do?

12. Exactly what sort of ion should an element from Column 6 of the Periodic table form?

13. Plants produce glucose. What are two different, major things they do with the glucose?

14. What happens to an atom or molecule if it goes through an oxidation reaction?

15. Assume the box barrier is permeable to all materials here. Label the picture to show all diffusion movements that should happen - label to show what would move in what direction.

           _______________________
           /         35% Substance "A"      /                                       12% Substance "A"
           /                                             /
           /            in Water                    /                                                 in Water
             /____________________________/       

16. Name two types of endocytosis.

17. If more Hydrogen ions (H+) are added to a solution, what happens to the solution's pH reading?

18. Fill in the blanks: _______________ molecules in a nucleus are coiled up into

a material called _______________ ; during cell  division  this  material  is  packed

into  individual pieces called _______________ .

19. What are two basic principles of the cell theory?

Answer any five of the following questions for 13 Points Each.
Note: if you answer more than five, only the first five will be corrected.

1. Name and describe three of the properties of water that make it somewhat unusual.

2. There are several types of membrane-based cell organelles found in the cytoplasm that do not have any DNA inside them. Name, describe, and give the function of three.

3. Name three types of adaptations living things use against osmotic pressure. For each, explain how that adaptation keeps osmotic pressure from harming the organisms.

4. On the lines, fill in the appropriate labels for six of the cell structures on the diagram.

This was a drawing of a eukaryote cell showing various structures.

5. Fill in the chart below for cell structures you might see with an electron microscope.

6. Name, describe the structure, and give the function of three features formed that are projections of the outer cell membrane.

Name Structure Function

7. Name and define three of the four structural levels of proteins.

8. The molecule shown below contains Carbon, Hydrogen, Nitrogen, and Oxygen. Using the surrounding bonds as clues, fill in on each dotted line which type of atom belongs there.

Answer as many as you are able. Wrong answers will not result in points being lost from the main exam.

The element Nitrogen is a main "ingredient" in which class of organic molecule? Four Points.

How are the bonding characteristics of Carbon an important aspect of its biological importance?  Four Points.

Antibody molecules have two functional ends. What, for four points each, does each end do?

Sometimes dangerous disease bacteria pick up an ability to resist antibiotic drugs without developing the resistance themselves. How do they do this? Five Points.

Why isn't glucose used directly to fuel reactions in cells? Four Points.

What makes osmosis so special that it gets its own special name, when everything else is covered by one broad term? Four Points.

People requiring intravenous fluids are given a saline (salt) solution rather than pure water. Why? Five Points.

Many materials, like pasta, paper, or clothing, soften when soaked in water. Based upon what you know from Chapter 3, what is happening on a molecular level? Ten Points.