Ch6 Part II Solutions and biological molecules

True/False

Indicate whether the statement is true or false.

____ 1. Water is a polar substance.

____ 2. In water, the oxygen is more negative because electrons spend more time around it.

____ 3. Water is considered the universal solvent because it can even dissolve lipids.

____ 4. Kool-aid is a solution and water is the solute.

____ 5. When salt (NaCl) is dropped into water the Na is pulled to the oxygen part of water breaking salt apart.

____ 6. A mixture is a combination of 2 or more substances that chemically combine.

____ 7. A heterogenous mixture is uniform throughout.

____ 8. A solvent is defined as what the solute dissolves in.

____ 9. A colloid is a solution whose particles don’t settle out.

____ 10. Hydroxide ions, OH- is what determines an acid.

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 11. When added to water an acid is a substance that releases which of the following into solution.

a. / hydroxide ions / c. / Hydrogen ions
b. / Negative ions / d. / positive ions

____ 12. What happens when you mix a strong acid with a strong base?

a. / You still get an acid because acids are stronger / c. / a neutral solution of water and salt
b. / You get a base because a base has a high pH / d. / a salt solution slightly basic

____ 13. A pH buffer does what?

a. / controls the pH level when too acidic or too basic / c. / keeps solutions basic
b. / keeps solutions acidic / d. / keeps solution alkaline

____ 14. Which of the following would be a good reason to maintain a certain pH in the body?

a. / all of the body in mostly a basic pH and should be kept basic / c. / The body operates mainly in the acidic range and should be kept acidic
b. / Various parts of the body operate at various pH levels and needs to adjust so as not to be too acidic or too basic. / d. / the body can operate in any pH range

____ 15. Which of the following elements is neccessary to be an organic molecule?

a. / nitrogen / c. / hydrogen
b. / oxygen / d. / carbon

____ 16. Organic molecules only have a few elements that can they can form from. Which of the following accounts for the diversity of organic molecules and their functions?

a. / the ability to form so many different kinds of bonds / c. / forming different shapes even with the same elements
b. / forming small molecules / d. / all the above

____ 17. Which of the following bonds does an organic compound not form?

a. / covalent / c. / single carbon bonds
b. / ionic / d. / double carbon bonds

____ 18. Which element would need to be removed from the molecule in Figure 6-2 to make it unsaturated?

Figure 6-2

a. / carbon / c. / oxygen
b. / hydrogen / d. / phosphorus

____ 19. A student set up four test tubes containing a carbohydrate solution in which to perform carbohydrate digestion. Supplies included amylase (enzyme that breaks down carbs) and an incubator. In which tube listed would carbohydrate digestion proceed most quickly?

a. / Tube 1: No amylase, room temperature (25°C)
b. / Tube 2: No amylase, body temperature (37°C)
c. / Tube 3: Amylase present, room temperature (25°C)
d. / Tube 4: Amylase present, body temperature (37°C)

____ 20. Which property is responsible for the fact that water and oil do not mix?

a. / density / c. / phase
b. / mass / d. / polarity

____ 21. Which is the best example of a solution and not a colloid

a. / blood / c. / paint
b. / milk / d. / salt water

____ 22. When added to water, how does an acid affect the pH and H+ concentration?

a. / Both pH and H+ decrease.
b. / Both pH and H+ increase.
c. / The pH decreases while the H+ increases.
d. / The pH increases while the H+ decreases.

____ 23. Which element is found in proteins but not carbohydrates or lipids?

a. / C / c. / N
b. / H / d. / O

____ 24. In humans and other multicelluar organisms, which substance plays a central role as a primary energy source?

a. / carbohydrate / c. / protein
b. / fat / d. / water

____ 25. Glycogen, used to store energy in the liver and muscle tissue, is an example of which type of molecule?

a. / carbohydrate / c. / saturated fatty acid
b. / protein / d. / steroid

____ 26. Amino acids are the building blocks of which macromolecule?

a. / carbohydrate / c. / lipid
b. / DNA / d. / protein

____ 27. An organism’s genetic information is stored in which type of macromolecule?

a. / DNA / c. / lipid
b. / carbohydrate / d. / protein

____ 28. Which of the following is not found in a fat?

a. / a glycerol head / c. / an unsaturated fatty acid
b. / a saurated fatty acid / d. / nitrogen

____ 29. Besides energy, fats can be used for....

a. / forming cell membranes with phospholipids / c. / making cholesterole and vitamin D
b. / forming steroid hormones / d. / all the above

____ 30. Which of the following is not a protein.

a. / sucrose / c. / antibodies
b. / hemoglobin / d. / collagen and elastin

____ 31. Which of the following is less likely to unfold regarding protein structure.

a. / primary folding / c. / tertiary folding
b. / secondary folding / d. / quantinary folding

____ 32. Besides a phosphate group and a sugar, what is the 3rd thing needed to make a nucleotide?

a. / glucose / c. / a nitrogen base
b. / a nucleic acid / d. / none of these

____ 33. The sugar that forms a nucleotide is....

a. / Ribose / c. / fructose
b. / Glucose / d. / sucrose

____ 34. How many different nucleobases are there to form DNA, a nucleic acid.

a. / 1 / c. / 3
b. / 2 / d. / 4

____ 35. Which of the following is a difference between RNA and DNA

a. / RNA is a single strand of nucleotides / c. / DNA has no oxygen
b. / DNA is a double strand / d. / all the above

____ 36. Sucrose is a...

a. / monosaccharide / b. / disaccharide

____ 37. Plants use polysaccharides to form....

a. / cellulose / b. / chitin

____ 38. Why do lipids make a good cell membrane?

a. / they allow polar substances in and out / b. / they dont break down in water

____ 39. Functional proteins are also known as....

a. / fibrous proteins / b. / globular proteins

____ 40. Nucleic acids, carbohydrates and proteins can also be refered to as...

a. / polymers / c. / macromolecules
b. / long chains of monomeres / d. / all the above

Ch6 Part II Solutions and biological molecules

Answer Section

TRUE/FALSE

1. ANS: T

This is the correct definition.

PTS: 1 DIF: Bloom's Level A | DOK 1 REF: 156

TOP: 6-5

2. ANS: T

This is true

PTS: 1 DIF: Bloom's Level C | DOK 1 REF: 158

NAT: LS_1b TOP: 6-6

3. ANS: F

false, it cannot.

PTS: 1 DIF: Bloom's Level D | DOK 1 REF: 159

NAT: LS_1b TOP: 6-6

4. ANS: F

This is false, water is the solvent

PTS: 1 DIF: Bloom's Level A | DOK 1 REF: 160

TOP: 6-7

5. ANS: T

true

PTS: 1 DIF: Bloom's Level C | DOK 2 REF: 161

TOP: 6-8

6. ANS: F

false, dont chemically combine.

PTS: 1 DIF: Bloom's Level D | DOK 1 REF: 165

TOP: 6-10

7. ANS: F

false is not uniform

PTS: 1

8. ANS: T

true

PTS: 1

9. ANS: T

true

PTS: 1

10. ANS: F

false, H ions

PTS: 1

MULTIPLE CHOICE

11. ANS: C PTS: 1

12. ANS: C PTS: 1

13. ANS: A PTS: 1

14. ANS: B PTS: 1

15. ANS: D PTS: 1

16. ANS: C PTS: 1

17. ANS: B PTS: 1

18. ANS: B

Two atoms of hydrogen would need to be removed.

Feedback
A / Removal of a carbon atom would break the chain.
B / Yes, removing hydrogen atoms would leave a double bond.
C / Oxygen atoms are not involved here.
D / There is no phosphorus in this molecule.

PTS: 1 DIF: Bloom's Level C | DOK 3 REF: 169

TOP: 6-13

19. ANS: D

Starch digestion would proceed most quickly in the presence of amylase at body temperature.

Feedback
A / An enzyme would increase the rate of the reaction.
B / An enzyme would increase the rate of the reaction.
C / The reaction would proceed more quickly at body temperature.
D / Well done.

PTS: 1 DIF: Bloom's Level F | DOK 3 REF: 159

TOP: 6-7

20. ANS: D

Water is polar while oil is nonpolar.

Feedback
A / This explains why oil floats on water, but not why they do not mix.
B / Mass of oil molecules is only slightly related to this idea.
C / Both substances are liquid.
D / Correct.

PTS: 1 DIF: Bloom's Level D | DOK 2 REF: 163

TOP: 6-8

21. ANS: D

A solution is a homegeneous substance that contains a solute dissolved in a solvent.

Feedback
A / This is a colloid.
B / See page 163.
C / This is a colloid.
D / Well done.

PTS: 1 DIF: Bloom's Level D | DOK 2 REF: 163

TOP: 6-9

22. ANS: C

The pH decreases as the H+ increases.

Feedback
A / Only pH decreases.
B / The pH would decrease.
C / Correct.
D / This is opposite of the correct answer.

PTS: 1 DIF: Bloom's Level D | DOK 2 REF: 164

TOP: 6-10

23. ANS: C

Proteins have nitrogen, but carbohydrates and lipids do not.

Feedback
A / All have C.
B / All have H.
C / Correct.
D / All have O.

PTS: 1 DIF: Bloom's Level B | DOK 1 REF: 168

NAT: LS_5b TOP: 6-12

24. ANS: A

Carbohydrate is the key substance for energy metabolism. Fat is used for storage but not typically as a direct energy source.

Feedback
A / Well done.
B / This is mostly for energy storage, not use.
C / This can be used for energy but that is not its main role.
D / Water does not provide energy, though it is essential for life.

PTS: 1 DIF: Bloom's Level C | DOK 2 REF: 168

NAT: LS_5b STA: LS.10.11 TOP: 6-13

25. ANS: A

Glycogen is made of glucose and is a carbohydrate.

Feedback
A / Correct.
B / See page 168.
C / Glycogen is not a fatty acid.
D / See page 168.

PTS: 1 DIF: Bloom's Level A | DOK 2 REF: 168–169

NAT: LS_5b STA: LS.10.11 TOP: 6-13

26. ANS: D

Amino acids are the building blocks of protein.

Feedback
A / Carbohydrates are made of sugar units.
B / DNA is made of nucleotides.
C / See page 170.
D / Correct.

PTS: 1 DIF: Bloom's Level B | DOK 2 REF: 170

NAT: LS_5b STA: LS.10.11 TOP: 6-12

27. ANS: A

DNA is the genetic material of the cell.

Feedback
A / Correct.
B / This provides fuel.
C / See page 171.
D / Protein is not the substance used to store the genetic information.

PTS: 1 DIF: Bloom's Level A | DOK 1 REF: 171

NAT: LS_5b STA: LS.12.1 TOP: 6-13

28. ANS: D PTS: 1

29. ANS: D PTS: 1

30. ANS: A PTS: 1

31. ANS: D PTS: 1

32. ANS: C PTS: 1

33. ANS: A PTS: 1

34. ANS: D PTS: 1

35. ANS: D PTS: 1

36. ANS: B PTS: 1

37. ANS: A PTS: 1

38. ANS: B PTS: 1

39. ANS: B PTS: 1

40. ANS: D PTS: 1