BI 171 - Third Exam - 2002
Answer Key
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.
___D___ 1. Ferredoxin is an important
component of
a.
Membranes
b.
Respiration
c. Signaling
d.
Photosynthesis
e. An old French song
...it moves electrons from chlorophyll complexes into
the actual
photosynthetic reaction.
___B___ 2. Waterproofing would have
evolved in early vertebrates to
a. Increase oxygen
uptake b. Keep water from flowing in
c. Decrease oxygen
uptake d. Keep water
from flowing out
e. Increase their profit margins
...these would have been freshwater fish, fighting the
influx of water
from a very dilute environment.
___A___ 3. Oxidation state is a
calculation of ______ in a molecule
a.
Electrons
b.
Atoms
c. Bonds
d. Oxygens
e. Mood
...remembering that oxidation involves loss of electrons will help here.
___D___ 4. In the lab experiment, the salt
solution was _____ to the cytoplasm.
a.
Oxidizing
b.
Isotonic
c. Hypotonic
d. Hypertonic
e. Insulting
...the prefix (hyper, more; hypo, less) refers to the particles in solution.
___C___5. The common molecular component
in all lipids has
a. Six
carbons
b. Four carbons
c. Three
carbons
d. Varying numbers of carbons
e. A habit of saying, "Does this component make me look
fat?"
...it's glycerol - the fatty acids vary, but the glycerol doesn't.
___A___6. A major difference between the Krebs Cycle and the Calvin Cycle
a. Calvin works simultaneously with multiple molecules, Krebs one at a time
b. Krebs works simultaneously with multiple molecules, Calvin one at a time
c. Calvin happens in the cytoplasm, Krebs on the cell membrane
d. Krebs happens in the cytoplasm, Calvin on the cell membrane
e. They both seem to have been named after major nerds
...photosynthesis (Calvin) is construction and has many
parts going in,
respiration is breaking up molecules one at a time. This is not a very
good question.
___B___7. Allosteric proteins have
a. Multiple
subunits
b. Multiple binding sites
c. Mirror-image
forms
d. Metal prosthetic groups
e. Good complexions - wait, that’s allo vera...
...they are regulated by binding inhibitors at a second binding site.
___A___8. What other than enzymes follows a Michaelis-Menten
pattern?
a.
Carriers
b.
ATP
c. Metabolism
d. Oxygen
debt
e. Two obscure guys
...the pattern of increased ability to work until all
workers are occupied
all the time.
___D___9. In the process NAD+ + H2 -----> NADH + H+ the NAD+ is
a.
Activated
b.
Oxidized
c. Transported
d.
Reduced
e. Changed in some term-heavy way
...the charge actually does reduce here.
___B___10. ATP is generated primarily by
a. Krebs and Calvin
cycles b. Electron transport systems
c. Glycolysis
d. Ionizing radiation
e. Judicious investment in little-known mutual funds
...this is just where most of the ATP is made regardless of the process.
___D___11. Ammonia is a product of metabolism of
a. Carbohydrates and
proteins
b. Lipids and proteins
c. Lipids and nucleic
acids
d. Proteins and nucleic acids
e. The smelly kind
...it's a nitrogenous waste and must come from
nitrogen-containing
compounds.
___D___12. The "fluid" part of the fluid
mosaic model refers to the
a.
Water
b.
Channels
c. Embedded proteins
d. Phospholipids
e. Part that isn’t the mosaic
...they flow around each other, held in place by hydrophobic "forces."
___D___13. Glycolysis produces a net
total of
a. Six ATPs
b. Four ATPs
c. Three ATPs
d. Two ATPs
e. A lousy job
...two get invested and four get made.
___C___14. At equilibrium, particle
movement is
a.
Stopped
b.
Slowed c. The same in all directions
d.
Accelerated
e. Vague
...it's part of the definition.
___C___15. As oxygen is used by cells, more
oxygen enters from the surroundings by way of
a. Active
transport
b.
Osmosis
c. Diffusion
d. Metabolism
e. A passkey
...using it reduces the concentration, setting up a gradient for diffusion.
___A___16. A single photon of light
a. Can excite a single chlorophyll electron
b. Can excite a single chlorophyll molecule
c. Can excite a single chlorophyll complex
d. Can drive a reverse respiration in the mitochondria
e. Can make a student’s brain explode
...that electron gets everything else going...
___B___17. How does oxygen fit into photosynthesis and aerobic respiration?
a. End steps of photosynthesis, first steps of aerobic respiration
b. First steps of photosynthesis, end steps of aerobic respiration
c. End steps of both.
d. First steps of both
e. It needs a bit of a twist before you shove it
...it's linked to the electron transport chains of each.
___B___18. In photosynthesis,
a. Glucose is used to produce ATP
b. ATPs are used to produce glucose
c. ATPs are not significant participants
d. Cell walls are used as the main location
e. All sorts of not-very-interesting things happen
...just part of the process.
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.
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1. Briefly describe how chemoautotrophs work. ...they use hot chemicals to gain energy for the synthesis of "fuel," or energy-containing molecules.
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2. This is tricky - what are two different ways that a cell can increase the flux of a particular material diffusing into it? (Some of the basic factors won’t work here...) Has to apply to a cell without killing it, so heating is out, and a cell can't change the particle size here. |
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Use the material, increasing the concentration gradient
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Increase cell surface area
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3. What are two different general types of signal ligands used in communication? |
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Pheromones Hormones |
Neurotransmitters Development Factors |
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4. What two processes occur during group translocation? |
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Enzyme-mediated change
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Transport through the cell membrane
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5. Briefly explain how fat is converted to use it for energy. ...it is broken down to acetyl coenzyme A and "fed" into the Krebs cycle.
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6. What are the two basic types of coupled reactions? |
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Reactions in a sequence
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Group Transfer between participants
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7. Other than carbon dioxide and water, what are two byproducts of anaerobic respiration? |
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Ethanol Pyruvic Acid |
Lactic Acid Propionic Acid |
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8. Briefly explain what is meant by assimilation of materials. ...materials are taken in and actually used.
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9. Briefly explain how domains are laid out in transmembrane proteins. ...domains lined up with the membrane middle are hydrophobic, domains facing the outside and inside are hydrophilic.
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10. In the situation below, show with labeled arrows the way things should move. Assume the barrier between the boxes is permeable to everything here. |
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40% Material X --------> in water
<-----------------------
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15% Material X in water |
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11. Name two different cells processes that require phosphorylation to occur. |
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Anything that requires energy (supplied by ATP through phosphorylation) - it's a long list.
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12. What are two different things that cells do with absorbed monomers? |
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- Use them in respiration for their energy.
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- Use them as components in cell polymers
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13. What is the significance of the Second Law of Thermodynamics in food webs? ...energy "leaks out" as food progresses along the sequence - it's lost to entropy as heat.
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14. What are two different types or examples of molecules that move freely through typical eukaryote cell membranes. |
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Materials small enough
to easily pass through the pores. |
Materials that are lipid-soluble and can dissolve through the membrane.
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15. What molecule "feeds into" the Krebs Cycle? ...acetyl coA (coenzyme A)
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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. Place the following types of electromagnetic
radiation with the proper star:
Green,
InfraRed, Red, UltraViolet, Violet, X-Ray.
LOW FREQUENCY
—[ ----------- VISIBLE LIGHT --------------] — HIGH FREQUENCY
*
*
*
*
*
*
These three must be visible.
Low Freq, less E -
IR, Red,
by
Green
Violet, by UV High Freq,
High
simple
heat
InfraRed
UltraViolet
E = X-Ray
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2. For each of three different types of molecular-level potentials, name the type and briefly describe how it works. |
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CHEMICAL
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Concentration gradient built up and held for release. |
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ELECTRICAL
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Charge differential built up and held for release. |
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GROUP TRANSFER
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High-E group held on molecule (commonly phosphate on ATP) for swap. |
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3. Four the four basic food chain levels, give the general name of the level and then give an example of one organism/species found locally that would clearly fit into that level. |
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PRODUCERS
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Any local plant. |
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PRIMARY CONSUMERS
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Any local plant-eater (stick with obvious plant-eaters) |
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SECONDARY CONSUMERS
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Any eater of plant-eaters. |
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DECOMPOSERS
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Anything that breaks down carcasses and/or wastes. |
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4. What steps take the starting glucose in glycolysis to the point where it becomes two molecules? Include the split in the steps. |
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A phosphate is added to non-ring Carbon. |
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Molecule shifted to be symmetrical, with 2 non-ring Carbons. |
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2nd phosphate added to 2nd non-ring Carbon. |
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Molecule splits into 2 phosphorylated, 3-Carbon molecules. |
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5. For the two steps of photosynthesis: |
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STEP NAME |
SOURCE MATERIALS / ENERGY |
PRODUCTS |
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LIGHT- DEPENDENT REACTION |
Light and Water |
ATP and NADPH |
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LIGHT- INDEPENDENT REACTION |
Carbon Dioxide (also ATP, NADPH) |
Glucose (also ADP, NAD+) |
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6. Explain briefly but step-by-step how a negative feedback loop produces regulation. Include both types of effects that can produce such loops. The number of lines here is not meant to suggest a number of steps. |
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Either the effect of a molecule or the amount of the molecules themselves veers from the optimum. |
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In response to this negative message, a system starts up to make more molecules. |
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More molecules are made and released. |
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The new molecules return the effect or the basic numbers to an optimum level. |
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Achieving the optimum causes molecule synthesis to stop, until the first step happens again. |
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7. Name and define four different kinds of proteins that commonly can be found in cell membranes. |
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CARRIERS |
Move materials across the barrier. |
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PORES |
Passive openings. |
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STRUCTURAL |
Hold parts of the membrane in place. |
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CHANNELS |
Openings with restricted access. |
| MARKERS | Identifies cell to other cells. |
| RECEPTORS | Picks up environmental information. |
| CONNECTORS | Holds cells together in multi-celled systems. |
| ENZYMES | Aid in reactions that occur "on" the membrane. |
NO KEY FOR 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 is the minimum amount of energy that an exergonic reaction must produce? Three Points.
Why or how does ATP do what it does? Be fairly specific. Four Points.
The dietary sources of NAD & FAD both are from the same specific class of nutrient? What is it, for Three Points?
What sorts of different commercial products are based upon the activity of anaerobic respiring organisms? Two Points each.
What types of organisms must process ammonia wastes to a totally nontoxic form? Three Points.
Briefly explain how certain types of materials can convert electromagnetic energy to other energy forms. What happens on the atomic level? Four Points.
Carotenoids - other than their "classic" purpose, what other functions might they have? Two Points each.
For Three Points each, briefly explain on what bases photosynthesis can vary among organisms.
The human body tracks carbon dioxide rather than oxygen when regulating breathing. Why? Three Points.