BI 171 - Second Exam - 1999
ANSWER KEY
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.
___C___ 1. A sugar, a nitrogenous base, and a phosphate are the components of
a(n)
a. Antibody
b. Enzyme
c. Nucleotide
d. Cytosol
e. Festive autumn drink
...just right out of the notes / book.
___D___ 2. In multicellular organisms, cell walls tend to limit
a. Metabolic rate
b. Cell size
c. Enzyme activity
d. Mobility
e. Meal choices
...since they stick cells together in a fairly inflexible manner...
___B___ 3. Temperature is a measurement of what at the atomic level?
a. Activation energy
b. Kinetic energy
c. Bonding energy
d. Optimal energy
e. Whether the atoms can call in sick
...it's the definition.
___B___ 4. Which cells would have the most rough endoplasmic reticulum and Golgi
apparatus?
a. Cells that produce and store lipid
b. Glandular cells that produce and secrete a protein hormone
c. Liver cells that detoxify drugs
d. Complex bacterial cells
e. Cells with the most available discretionary cash
...the RER is linked to production and the Golgi to export / secretion.
___A___5. Thykaloid membranes would be found in the cells of a
a. Lettuce
b. Bacterium
c. Dog
d. Fungus
e. Thykaloid
...they're part of plant cells' chloroplasts.
___C___6. An antibody's ability to bind only to a particular antigen is an example of
a. Homology
b. Analogy
c. Stereospecificity
d. Affinity
e. Really anal-neurotic molecules
...which makes it very specific. Affinity has to do with
binding
strength but not specificity.
___A___7. Proteins are constructed in living things starting with the
a. N- terminus
b. Middle
c. C- terminus
d. Subsidiary chains
e. Proper notarized bids
...if you remember amino terminus and carboxyl, it's alphabetical
___C___8. Chaperonins are involved in
a. Enzyme regulation
b. Gene expression
c. Protein folding
d. Rate equilibrium
e. Molecule proms
...again, pretty much a definition.
___D___9. Cooperative effect works on which structure level?
a. Primary
b. Secondary
c. Tertiary
d. Quaternary
e. Hmmm....this could be useful...
...quaternary is the only level with separate subunits to cooperate
...the charged gel migrates according to charge and the smaller
bits migrate faster if they're charged equally.
___A___11. The designation k is given to the
a. Reaction rate
b. Optimal pH
c. The active site
d. The reaction product
e. Whatever they put into the cereal
...you've got to know this for most of chapter 4 to make any sense at
all
___A___12. A reaction with an equilibrium constant of more than 1 tends to
move forward; the Keq is calculated by
a. Dividing product concentration by reactant concentration
b. Multiplying product concentration by reactant concentration
c. Dividing reactant concentration by product concentration
d. Multiplying reactant concentration by product concentration
e. Asking somebody else to figure it out for you
...if you understand how this works you can figure it out; otherwise
you just have to remember it.
___A___13. A nucleolus should have a sizeable amount of
a. RNA
b. DNA
c. Glycocalex
d. Membranes
e. Free pizza coupons
...since its job mostly involves being an RNA repository and
synthesizer, that makes sense...
___D___14. The structure of an amino acid:
a. The R group, alpha carbon and carboxyl are on the amino group
b. The R group, alpha carbon and amino group are on the carboxyl group
c. The alpha carbon, amino and carboxyl groups are on the R group
d. The amino, carboxyl, and R groups are on the alpha carbon
e. There's a bunch of stuff stirred up in a mess
...just remember what the "center" is...
___D___15. The number of substrates that an enzyme molecule can process per second:
a. Rate constant
b. Optimal constant
c. Equilibrium constant
d. Turnover number
e. Depends on whether the enzyme is on straight hourly or piecework payscale
...another definition.
___B___16. A ligand is equivalent to a(n)
a. Enzyme
b. Substrate
c. Codon
d. Cofactor
e. A meth (it's a spelling joke)
...a substrate by another name, for receptors and such...
___A___17. A cell covered with microvilli would most likely be doing which job?
a. Absorbing materials
b. Moving through water
c. Photosynthesizing
d. Holding tissues together
e. Making really tiny pasta
...the microvilli increase surface area, so what's a cell need surface
for-? Absorbing or releasing.
___B___18. Proteins that are homologous would certainly be similar in
a. Function
b. Amino acid sequence
c. Cofactor usage
d. Mutational patterns
e. Baseball team preferences
...similar to anatomical homologies, built on roughly the same basis
1. What are two facts that support the endosymbiont theory for mitochondria?
...there
are a few: mitochondria are structurally similar to aerobic
bacteria; they have bacteria-type DNA (or they have at least some of
their own DNA); similar symbioses can be observed in nature.
2. What is a Q10?
...the increase in a reaction's rate with a
10-degree Celsius increase in temperature.
3. What are two typical elements of cytoskeleton?
...there are three: microtubules,
microfilaments, and intermediate filaments.
Membranes might be an allowable answer but are not usually considered as
such.
4. What's the basic difference between a mineral-based prosthetic group and a mineral-based
cofactor? Be sure to indicate which is which.
...a
prosthetic group is included as part of a functioning protein; a
cofactor may be needed for proper function, but it is essentially
separate.
5. Name two features of flagella that make them distinctly different from cilia.
...they are bigger, almost always found in much smaller numbers on a cell, and may have added substructures (cilia don't).6. What is (define!) a catalyst?
...something that speeds up a reaction (by lowering activation energy, but that's not a required part of this definition) and which itself comes out of the reaction unchanged. This last part is needed, because reactants could be defined, sort of, with the first part.7. Define activation energy.
...the energy / input needed to get a reaction started.8. What sorts of bond types can be found holding various proteins together?
...mostly Hydrogen, sometimes covalent, rarely ionic.
9. Describe two different types of indirect enzyme inhibitions.
...indirect has to be something attaching away from the active site. It could block access of the substrate, or change the shape of the active site.
...an enzyme made of RNA (rather than protein).
11. In Nature, what is a limiting factor? Explain it generally rather than giving an example.
...it's a single aspect of the system that by
itself can affect whether or to what extent the system functions.
A single system could have lots of limiting factors - the one that
actually is in smallest supply is the limiting factor in any
ecosystem. (Plants could have water, phosphate, nitrate, iron, or
other limiting factors - whatever's hardest to come by will limit plant
growth)
12. What are two rules included in the Cell Theory?
...there are several: all living things are made up of at least one cell; cells are the smallest unit consider living; cells only come from similar pre-existing cells; cells are more similar than different; multicellular function is a product of component cells & their interactions.
...it's an equaling of rate - reactions
continue, things change, but rates forward and backward are equal.
14. Briefly explain the typical ionization patterns found in amino acids.
...the carboxyl ends tend to lose hydrogen ions and go negative; the amino ends tend to pick hydrogen ions up and go positive.15. What is the evolutionary importance of genetic redundancy?
...you could answer this for either redundancy: it could reduce the impact of specific mutations, allowing high mutation rates; it allows genes to mutate and have their original function preserved (by having copies mutate).16. What exactly happens at the active site of an enzyme?
17. What is apoptosis?
..."programmed cell death" - a cell dies because its "timer" goes off or because it is signaled to die.
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.
Six Points Each. Partial credit is possible.
| Type:
ELECTRON
|
LIGHT |
|
Able to see smaller things;
Advantages over Other(2): More common advanced research tool; More commonly used for illustrations. | Just reverse the terms around... |
|
Expensive.
Disadvantages Harder to use. vs Other(2): Treatment of specimens is more potentially dangerous. |
| PRIMARY | Order of amino acids on chain. |
| SECONDARY | Local binding patterns. |
| TERTIARY | "Wrapping up" shape in 3 dimensions. |
| QUATERNARY | How multiple subunits interact in single protein. |
| None - same amino acid is coded. |
| None / minimal - similar amino acid is coded or amino acid change is in noncritical part of protein. |
| Major - protein function is impaired. |
| Protein function is improved. |
| CELL MEMBRANE | CELL WALL (common enough) | CHROMOSOME(even though structurally different) |
| RIBOSOMES | CYTOPLASM | FLAGELLUM (even though structurally different) |
| INTERNAL MEMBRANES (even though rarer in prokaryotes) |
| Help speed up reaction rates (as enzymes) | Pick up information from environment (as receptors) |
| Aid in recognizing and fighting invaders (Immunity elements) | Used in structure |
| Used to produce movement | Used to carry or store materials |
| Used to control processes | Used as communication medium |
6. For an enzyme whose optimal temperature is 37o Celsius, briefly discuss what's happening to the molecules involved (don't just discuss reaction rates!) at...
| Temperatures below 37o: | Rise in temperature contributes to faster rates, until heat starts to affect shape of enzyme molecules. |
| At 37o: | Heat effect on enzyme just balances heat effect on rate. |
| Temperatures above 37o: | Heat effect on enzyme causes more and more to be nonfunctional at any given moment, until all are denatured and do not renature. |
7. Michaelis-Menten Kinetics can be represented on a graph. Draw the graph, with axes properly labeled, and describe what's going on for the two main slopes and the transition point.
|
|
NO ANSWERS FOR BONUS QUESTIONS.
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.
What sorts of different non-protein materials are produced as structural materials in organisms? Three Points each.
What might be the advantage of not lowering a low-grade fever that has resulted from a bacterial
infection? Be specific. Four Points.
Why isn't it reasonable that an enzyme would catalyze a reaction equally in both directions?
Four Points.
What minerals can spur the growth of fresh-water algae? Three Points.
What minerals, according to a current
theory, are needed to insure the growth of
salt-water algae? Three Points.
Why exactly would an organism need a
contractile vacuole? Four Points.