functional biology final exam

1.

1 point

Humans can digest starch but not cellulose because ________.

humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β- glycosidic linkages of cellulose

humans have enzymes that can hydrolyze the β-glycosidic linkages of starch but not the α- glycosidic linkages of cellulose

starch monomers are joined by covalent bonds and cellulose monomers are joined by ionic bonds

the monomer of starch is glucose, while the monomer of cellulose is galactose

2.

1 point

Which mode of energy production produces the most ATP per glucose?

Aerobic respiration

Fermentation

Anaerobic respiration

They all produce the same amount of ATP because they can all start with the same initial substrate, glucose.

3.

1 point

You make a phospholipid bilayer with short, saturated hydrocarbon tails. You measure the permeability of this membrane to oxygen. You then double the length of the hydrocarbon tails and re-measure membrane permeability. You then double the length of the hydrocarbon tails again and make a third measurement of membrane permeability. You graph membrane permeability as a function of hydrocarbon tail length. Which of the accompanying graphs best represents the data you expect?

(picture with slop upward slope)

(picture with downward slope)

(picture with curve)

(picture with straight line)

4.

1 point

Which of these provides evidence of the common ancestry of all life?

ubiquitous use of catalysts by living systems

near universality of the genetic code

structure of the nucleus

the flow of genetic information from DNA to RNA to protein

5.

1 point

Nucleic acids have a definite polarity, or directionality. Stated another way, one end of the molecule is different from the other end. How are these ends described?

One end has a hydroxyl group on the 2 carbon; the other end has a hydrogen atom on the 2 carbon.

One end contains a nitrogenous base; the other end lacks it.

One end has an unlinked 3' carbon; the other end has an unlinked 5 carbon.

One end has one phosphate group; the other end has two phosphate groups.

6.

1 point

Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will phagocytize asbestos but are not able to degrade it. As a result, asbestos fibers accumulate in ________.

mitochondria

ribosomes

peroxisomes

lysosomes

7.

1 point

What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?

ER → Golgi → nucleus

Golgi → ER → lysosome

nucleus → ER → Golgi

ER → Golgi → vesicles that fuse with plasma membrane

8.

1 point

Cooking oil and gasoline (a hydrocarbon) are NOT amphipathic molecules because they ________.

do not have a polar or charged region

do not have a nonpolar region

have hydrophobic and hydrophilic regions

are highly reduced molecules

9.

1 point

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________.

5'TAACGT3'

3'TAACGT5'

3'UAACGU5'

10.

1 point

A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, ________.

mitochondria and chloroplasts

chloroplasts and mitochondria

peroxisomes and chloroplasts

chloroplasts and peroxisomes

11.

1 point

Starch and cellulose ________.

are polymers of glucose

are cis-trans isomers of each other

can be digested by humans

are used for energy storage in plants

12.

1 point

Which of the following statements best describes the fundamental difference between prokaryotic and eukaryotic cells?

Eukaryotic cells lack a cell wall, whereas prokaryotic cells have a cell wall.

Eukaryotic cells have a nucleus, whereas prokaryotic cells do not have a nucleus.

Eukaryotic cells have ribosomes, whereas prokaryotic cells do not have ribosomes

Eukaryotic cells have a plasma membrane, whereas prokaryotic cells do not have a plasma membrane.

13.

1 point

When polymerization of a protein is complete, but a protein is still completely linear, what is the highest level of structure in the protein?

primary

secondary

tertiary

14.

1 point

Oxidation is the __________.

gain of electrons

gain of a hydrogen

gain of neutrons

loss of electrons

15.

1 point

9. An atom (such as C) had four electrons in its valence shell. What types of covalent bonds is it capable of forming?

Single, double, or triple

Single and double

Single bonds only

Double bonds only

16.

1 point

You have a polymer of DNA with 10 adenine bases followed by 10 cytosine bases. If that strand bonded to a strand of 20 thymine bases, how would the double helix shape vary from a typical DNA double helix?

The double helix would be longer than normal.

The double helix would be shorter than normal.

One strand of the double helix would be longer than the other strand

The width of the double helix would vary along the length of the strand.

17.

1 point

Tay-Sachs disease is a human genetic abnormality that results in cells becoming packed with very large undigested lipids. Which cellular organelle is malfunctioning in this condition?

lysosomes

Mitochondria

Golgi apparatus

Rough endoplasmic reticulum

18.

1 point

Nitrogen (N) is more electronegative than Hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?

Each H atom has a partial positive charge; the N atom has a partial negative charge.

Ammonia has an overall positive charge

Ammonia has an overall negative charge

The N atom has a partial positive charge; each H atom has a partial negative charge

19.

1 point

ATP releases energy via __________.

hydrolysis

oxidation

reduction

dehydration

20.

1 point

Celery stalks that are immersed in freshwater for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the freshwater ________.

and the salt solution are both hypertonic to the cells of the celery stalks

and the salt solution are both hypotonic to the cells of the celery

is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

is hypertonic and the salt solution is hypotonic to the cells of the celery stalks

21.

1 point

If a double-stranded DNA sample were composed of 10 percent thymine, what would be the percentage of guanine?

10

20

40

It is impossible to tell

22.

1 point

The lock-and-key analogy for enzymes applies to the specificity of enzymes ________.

as they form their tertiary structure

as they form their tertiary and quaternary structure

binding to their substrate

interacting with water

23.

1 point

Enthalpy is the __________.

amount of disorder in a molecule

exothermic status of a reaction

total amount of energy in a molecule

endothermic status of a reaction

24.

1 point

In what important way does competitive inhibition differ from allosteric inhibition?

During competitive inhibition, a regulatory molecule binds to the active site, whereas during allosteric inhibition, a regulatory molecule binds to a site other than the active site

During competitive inhibition, a regulatory molecule binds to a site other than the active site

Allosteric inhibition is important in maintaining homeostasis, whereas competitive inhibition is not.

There is no difference; they are two different terms that mean the same thing.

25.

1 point

A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead. If so, then jump-starting the car from a good battery will solve the problem. In doing so, you are_____.

Testing a theory for why the car will not start

making observations to inspire a theory for why the car will not start

starting hypothesis and using that hypothesis to make a testable prediction

comparing multiple hypotheses for why the car will not start

26.

1 point

Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely ____.

Positively charged

Negatively charged

Without charge

Hydrophobic

27.

1 point

How does a scientific theory differ from a scientific hypothesis?

Theories are proposed to test scientific hypothesis

theories are usually an explaination for a more general phenomenon; hypothesis typically adress more specific issues

Hypothesis are usually an explaination for a more general phenomenon; theories typically address more specific issues.

confirmed theories become scientific laws, hypothesis become theories.

28.

1 point

How many oxygen molecules (O2) are required each time a molecule of glucose (C6H12O6) is completely oxidized to carbon dioxide and water via aerobic respiration?

1

3

6

2

29.

1 point

Dairy cattle were unknown in Thai culture until recently, and 97 percent of Thai people are lactose intolerant as adults. Which explanation for such widespread lactose intolerance is most likely correct?

a. Allergies are becoming more common in humans as more chemicals are being encountered during longer lifetimes.

Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.

The ability to digest sugar in milk is determined by environment, and most humans are not exposed to milk as a food source beyond childhood years.

There is no good explanation for this situation in humans.

30.

1 point

Suppose you discovered a new amino acid, its R-group contains only hydrogen and carbon atoms, Predict the behavior of this amino acid.

It is hydrophobic

It is hydrophilic

Relative to the amino ads found in organisms, s interactions with water will be intermediate

Relative to the amino acids found in organisms, its interactions with water will be very high

31.

1 point

Which of the following descriptions best fits the class of molecules known as nucleotides?

a nitrogenous base and a phosphate group

a nitrogenous base and a sugar

a nitrogenous base, a phosphate group, and a sugar

a phosphate group and an adenine or uracil

32.

1 point

Which of the following statements is TRUE about enzyme-catalyzed reactions?

The reaction is faster than the same reaction in the absence of the enzyme.

The free-energy change of the reaction is opposite from the reaction that occurs in the absence of the enzyme

An enzyme catalyzes a reaction by raising the activation energy

Enzyme-catalyzed reactions require energy to activate the enzyme.

33.

1 point

Cell walls are used by many different organisms for protection from their environment and structural support. These cell walls must obviously be insoluble in water; otherwise, they would dissolve the first time an organism got wet. Which of the following carbohydrates would you expect to be most soluble in water?

starch

peptidoglycan

cellulose

chitin

34.

1 point

The chemical reaction illustrated in the figure below ________.

is a hydrolysis reaction

results in a peptide bond

joins two fatty acids together

links two polymers to form a monomer

35.

1 point

You have discovered an enzyme that can catalyze two different chemical reactions. Which of the following is most likely to be correct?

The enzyme contains α-helices and β-pleated sheets

The enzyme is subject to competitive inhibition and allosteric regulation

Two types of allosteric regulation occur: The binding of one molecule activates the enzyme, while the binding of a different molecule inhibits it

Either the enzyme has two distinct active sites or the reactants involved in the two reactions are very similar in size and shape.

36.

1 point

Knowing the atomic mass of an element allows inferences about which of the following?

the number of electrons in the element

the number of protons in the element

the number of nuetrons in the element

the number of protons plus nuetrons in the element

37.

1 point

The reaction that combines acetyl-CoA and oxaloacetate to form citrate (citric acid) is part of _____________.

the citric acid cycle

Fermentation

glycolysis

pyruvate oxidation

38.

1 point

A glyosidic linkage is analogous to which of the following in proteins?

an amino group

a peptide bond

a disulfide bond

a β-pleated sheet

39.

1 point

A certain eukaryotic cell type specializes in synthesizing lipids. Which organelle would be found in greater abundance in this cell type than in other cell types that do not synthesize lipids?

lysosomes

Mitochondria

Smooth endoplasmic reticulum

Rough endoplasmic reticulum

40.

1 point

Which of the following statements describes a fundamental difference between plant cells and animal cells?

Animal cells do not have chloroplasts.

Plant cells do not have mitochondria.

Plant cells do not have a Golgi apparatus

Animal cells do not possess chromatin.

41.

1 point

What results from the chemical reaction illustrated above? The reactants have no charge.

A cation with a net charge of +1 and an anion with a net charge of -1

b. A cation with a net charge of -1 and a anion with a net change of -1

c. A cation with a net charge of -1 and a anion with a net charge of +1

d. A cation with a net charge of +1 and an anion with a net charge of -1

42.

1 point

Even though plants cells photosynthesize, they still use their mitochondria for oxidation of pyruvate. This will occur in ________.

photosynthetic cells in the light, while photosynthesis occurs concurrently

nonphotosynthesizing cells only

cells that are storing glucose only

all cells all the time

43.

1 point

Lipids that form membranes have what kind of structure?

polar heads and polar tails, which allows them to interact with water on both sides of the membrane

completely polar, which allows them to dissolve in water

polar heads and nonpolar tails; the nonpolar tails interact with water

polar heads and nonpolar tails; the polar heads interact with water

44.

1 point

Which of the following are qualities of any good scientific hypothesis?
I. it is testifiable
II.it is falsifiable
III. it produces quantitative data.
IV. it produces results that can be replicated.

I only

II only

III only

I and II

45.

1 point

Upon chemical analysis, a polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein?

101

100

99

98

46.

1 point

Which of the following organelles have a double membrane?

Ribosome, rough endoplasmic reticulum, and

Nucleus, mitochondria, and chloroplasts

Smooth endoplasmic reticulum, lysosomes, and the cytoskeleton

Golgi apparatus, peroxisomes, and cytoplasm

47.

1 point

The tertiary structure of a protein is the ________.

bonding together of several polypeptide chains by weak bonds

order in which amino acids are joined in a polypeptide chain

unique three-dimensional shape of the fully folded polypeptide

organization of a polypeptide chain into an α-helix or β-pleated sheet

48.

1 point

You have just discovered an organism that lives in extremely cold environments. Which of the following would you predict to be TRUE about the phospholipids in its membranes, compared to phospholipids in the membranes of organisms that live in warmer environments?

The membrane phospholipids of cold-adapted organisms will have longer hydrocarbon tails.

The membrane phospholipids of cold-adapted organisms will have shorter hydrocarbon tails.

The membrane phospholipids of cold-adapted organisms will have more saturated hydrocarbon tails.

The membrane phospholipids of cold-adapted organisms will have more unsaturated hydrocarbon tails.

49.

1 point

Cells are _____.

Only found in pairs, because single cells cannot exist independently

limited in size to 200 and 500 micrometers in diameter

characteristic of eukaryotic but not prokaryotic organisms

characteristic of prokaryotic and eukaryotic organisms

50.

1 point

Gibbs free energy change __________.

determines the amount of enzyme needed

determines whether a reaction is spontaneous or not

determines the amount of potential energy gained

determines the amount of kinetic energy lost