BI 171 - Third Exam - 2005

 

Multiple Choice.

Place the letter of the choice that best answers the question on the line to the left.
Two Points Each. NOTE: "e" answers are never the correct answer.

 

_______ 1.  Movement of materials within a cell can be accomplished by

                    a. Mitochondria and chloroplasts
                    b. Microtubules and endoplasmic reticulum
                    c. Ribosomes and microfilaments
                    d. Flagella and cilia
                    e. Tiny rubber bands and teeny spitball launchers

 

_______ 2. Cofactors are commonly

                    a. Minerals                 b. Coenzymes                 c. Carbohydrates
                    d. Enzymes                             e. Paid less than factors

 

_______ 3.  Cells going through apoptosis generally

                    a. Exist in low- or no-oxygen environments          b. Increase their surface area
                    c. Produce poisons                                            d. Digest themselves
                                                e. Donít even speak Greek

 

_______ 4.  Histones are most active during the early steps of

                    a. Microtubule production                         b. DNA transcription
                    c. Enzyme activation                                d. DNA translation
                                        e. Warm-ups for
American Idol

 

_______ 5.  Variations in pH affect enzyme activity mostly because they can affect

                    a. Stability of substrates                             b. Temperature
                    c. Stability of products                               d. Hydrogen bonds
                                    e. Where the capital letters are placed

 

_______ 6.  In a coupled reaction

                    a. Enzyme one feeds product to enzyme two
                    b. Endergonic feeds energy to exergonic
                    c. Exergonic feeds energy to endergonic
                    d. Reaction one feeds product as reactant into reaction two
                    e. Thereís a modest ring ceremony and a conservative protest

 

_______ 7.  Chaperonins should be found near

                    a. Ribosomes             b. Chromosomes            c. Cell membrane
                    d. Microfilaments                        e. Tiny proms

 

_______ 8.  When liver cells remove sugar from the blood, the concentration in the liver cells
                        is higher than levels in the blood. This movement involves

                    a. Passive transport             b. Respiration            c. Active transport
                    d. Transcription                            e. A series of sharp right turns

 

_______ 9.  Root pressure is generated by

                    a. Respiration                 b. Osmosis                 c. Photosynthesis
                    d. Pumps                             e. Leaves making fun of the roots

 

_______ 10.  Centromeres can attach to

                    a. Messenger RNA             b. Membranes            c. Ribosomes
                    d. Microtubules                        e. Random freaks met in bars

 

_______ 11.  A cell membraneís phospholipid molecules have

                    a. A single phosphate instead of a fatty acid
                    b. Two phosphates instead of two fatty acids
                    c. Phosphate instead of glycerol
                    d. Phosphate instead of cholesterol
                    e. Very poor self images

 

_______ 12.  Affinity exists between

                    a. Neighboring cells                             b. Enzymes and substrates
                    c. Genes and proteins                          d. DNA and RNA
                                e. What you think it is and what it really is

 

_______ 13.  Pseudopods are commonly used for

                    a. Swimming                 b. Communication                c. Crawling
                    d. Reversing flux                    e. Examples of nasty terminology

 

_______ 14.  When proteins are inserted into membranes, they take up a proper position due to

                    a. Chaperonins                            b. Hydrophobic domains
                    c. Prosthetic groups                     d. Covalent bonding to membrane molecules
                            e. Their refined breeding and elegant upbringing

 

_______ 15.  Activators, promoters, and enhancers work in

                    a. Adjusting flux across a membrane
                    b. DNA transcription
                    c. Bringing enzyme-mediated rates to equilibrium
                    d. Cell reactions to changing temperature
                    e. The music industry

 

_______ 16.  A cell would have a contractile vacuole when its surroundings are

                    a. Hypertonic or hypotonic               b. Hypertonic only
                    c. Hypotonic only                            d. Hypertonic, hypotonic, or isotonic
                                            e. Really, really contractile

 

_______ 17.  Two proteins with similar primary structures have different functions - they are

                    a. Both analogous and homologous
                    b. Neither analogous nor homologous
                    c. Analogous but not homologous
                    d. Homologous but not analogous
                    e. This is seriously deja vuíd, dude!

 

_______ 18.  Which best explains why plant cells have golgi bodies?

                    a. Cell walls are a type of secretion
                    b. Cell walls are made of carbohydrates
                    c. Photosynthesis produces many waste materials
                    d. Chloroplasts have to able to leave the cell
                    e. They got them on sale

 

Short Answer.

Pick NINE questions to answer in the spaces provided.
NOTE
: if you answer MORE than nine, only the first nine will be corrected.
Four Points each. Partial credit is possible.

1.  Transfer RNA binds temporarily to what two other types of molecules?
 

 

2.  What is a function of peroxisomes?

 

 

 

3.  There are two factors that make reaction rate drop at temperatures below optimum. What are they?
 

 

4.  Using the table attached to the exam (detach it if you need to), translate this gene sequence into an amino acid sequence -

T A C G G C A A C C G A T T T C T C T T C A T C

 

 

 

5.  How is a nuclear envelope structurally different from other internal membranes?

 

 

 

6.  What are two different ways to prevent an enzyme-catalyzed reaction from reaching equilibrium?
 

 

7.  What is an allosteric effect?

 

 

8.   In cell chemistry, what is a turnover number?

 

 

 

9.  Briefly explain how the codon version of genetic redundancy works.

 

 

 

10.  Define Q10.

 

 

 

11.  What are two ways that prokaryote chromosomes differ from eukaryote chromosomes?
 

 

12. Why is mitochondrial DNA more useful in evolutionary studies than nuclear DNA?

 

 

 

13.  What is an exon?

 

 

14.  What are two different structures that are microtubule-organizing centers?
 

 

Long Answer.

Select and answer completely any four of the following questions.
Note:
if you answer more than four, only the first four will be corrected.
Seven Points Each. Partial credit is possible.

1.  For three factors that can affect the rate at which flux moves toward equilibrium, give the factor and explain how that factor has to change to speed the rate up.
 

 

 

 

 

 

2.  Briefly describe three different ways that enzymes can be inhibited.
 

 

 

 

 

 

3.  Give three sets of differences between -

CILIA

MICROVILLI

 

 

 

 

4. For the drawing below, label any four different types of organelles or structures.

 

 

 

 

 

 

 

5.  For each type of cytoskeleton component, name the component and then give one fact about that component.
 

 

 

 

 

 

6.  In the graph below of Michaelis-Menten Kinetics, explain why the curve is doing what itís doing at each marked point, in terms of the enzymes at work.
 

Link to graph type (marks were on upslope, near top, and along top level)

 

 

7.  Describe the functions of three different types of membrane proteins.
 

 

 

 

 

 

 

Link to Answer Key

BONUS QUESTIONS.

Answer as many or as few as you wish. You can't lose points on the rest of the exam by getting these wrong. Partial credit is possible.

For Three Points Each, what sorts of functions have been discovered for what used to be called Junk DNA?

 

 

What two areas of money-rich research are interested in the function of telomeres? Three Points Each.

 

 

Why doesnít reversibility exactly apply to enzyme-catalyzed reactions? Three Points.

 

 

Explain why a metabolic pathway trait has to be a multiple gene trait. Three Points.

 

 

In a graph of enzyme-catalyzed reaction rate and temperature, what sort of organisms typically have very broad but fairly short curves? Three Points.

 

 

GENE TRANSLATION TABLE

CODONS ON MESSENGER RNA

 

First

Letter

SECOND

LETTER

Third

Letter

U

C

A

G

phelyalanine

serine

tyrosine

cysteine

U

U

phelyalanine

serine

tyrosine

cysteine

C

leucine

serine

STOP

STOP

A

leucine

serine

STOP

tryptophan

G

leucine

proline

histidine

arginine

U

C

leucine

proline

histidine

arginine

C

leucine

proline

glutamine

arginine

A

leucine

proline

glutamine

arginine

G

isoleucine

threonine

asparagine

serine

U

A

isoleucine

threonine

asparagine

serine

C

isoleucine

threonine

lysine

arginine

A

*START*

methionine

threonine

lysine

arginine

G

valine

alanine

aspartate

glycine

U

G

valine

alanine

aspartate

glycine

C

valine

alanine

glutamate

glycine

A

valine

alanine

glutamate

glycine

G

Itís okay to tear this sheet off the exam.

 

BI 171

McDarby

 

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