Biology
Señor Robles
70 Things I know about Macromolecules ANSWERS!
I am soooooooo smart
Carbohydrates
1. What is the general term used for macromolecules containing only the elements carbon, hydrogen, and
oxygen? Carbohydrates
2. What molecular formula do (ALMOST) all monosaccharides share? C6H12O6
3. What do you call molecules (such as the monosaccharides glucose and fructose) which share the same
formula but are arranged differently? Isomers
4. What chemical indicator is used to show the presence of monosaccharides? Benedict’solution
5. When two monosaccharides are chemically bonded together, what is the general term for the resultant
(and twice as large) molecule? Hint: read the next two questions. Dissacharide
6. A water molecule is removed in the formation of a bond linking together monosaccharides. What are
the two names for this process? Dehydration synthesis (and condensation reaction, but don’t worry about that one)
7. A disaccharide can be broken into its component parts by the addition of water. What’s this process
called? Hydrolysis
8. Glucose + Glucose → ? Maltose
9. Glucose + Fructose → ? Sucrose
10. What do you call any chain of glucose molecules linked together? A polysaccharide
11. What type of atom connects any two glucose molecules in any polysaccharide (or any two
monosaccharides in a disaccharide)? Oxygen
12. Glucose + Glucose + Glucose + Glucose + Glucose etc. in long chains side by side → ? Cellulose
13. What type of bond holds these chains together on their sides? Hydrogen
14. Where is the above polysaccharide found, and what is it used for? Plant cell walls / structural support
15. What do we call it in the human diet, and how is it beneficial? (dietary) fiber / exercise your intestines
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16. What is the storage form of sugar found in the roots and tubers of plants? Describe its shape.
Starch / branched chain
17. What is the principle storage form of sugar found in vertebrates? (Your liver makes and stores this
when there is too much glucose in your blood.) How do you describe its shape?
Glycogen / branched chain
18. What modified polysaccharide can be found in animals, in the form of the tough exoskeleton of insects
and crustaceans?
Chitin
19. Where else can this structural material be found? Fungal cell walls
20. How is this polysaccharide “modified?” The addition of amino groups to each glucose
21. What are the monomers that link together to form any carbohydrate polymer? Glucose
22. What is the difference between the terms polymer and polysaccharide?
A polymer is any large molecule composed of repeated similar units
A polysaccharide is a specific polymer, namely a series of glucose rings
23. What chemical indicator tells of the presence of polysaccharides like starch?
Lugol’s iodine
24. What simple sugar seems to be the sweetener of McDonald’s shakes?
Fructose (in the form of High Fructose Corn Syrup)
25. Describe how it is made:
Corn is milled into starch, starch is converted into glucose using enzymes, up to 90% of the glucose is
converted into fructose using other enzymes.
26. What is the main health concern with HFCS?
It has been shown that HFCS causes obesity
27. How is this reflected in the human population?
28. How is it that fructose is more fattening than sucrose?
29. Draw the structural formula for glucose.
Lipids
30. What lipids (or fats) are structurally different from other lipids because they are composed of four
linked carbon rings? Steroids (although some are actually “sterones”, --steroids that act like hormones.)
31. What are three examples of these special lipids? Estrogen, testosterone, & cholesterol
32. What lipids are composed of two fatty acid chains linked to a glycerol and a phosphate group?
phospholipids
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33. Lipids don’t like water. What term describes this? hydrophobic
34. What term describes the region of some fat molecules that is water tolerant? hydrophilic
35. Most fats/lipids are involve with energy storage, but some (like phospholipids and wax) have other
purposes. What are they involved with? Cell membrane structure
36. If you were stranded on a desert island with very little food, would you rather have a pound of starch or
a pound of lard? Why? Lard, because it has more calories for its mass
37. Fatty acids (and amino acids) always have this trademark group of four atoms: COOH (carboxyl)
38. What does an unsaturated fat molecule have that a saturated fat molecule does not? A double bond
39. When your body burns fat, and therefore oxidizes fatty acids, what poisonous compound is released
into your blood? Hydrogen peroxide (H2O2)
40. What term applies to the fat molecule made of a single glycerol molecule attached to three fatty acid
chains? triglyceride
41. What is the difference between HDLs and LDLs?
42. What are trans fats, and what’s wrong with them?
43. Why do fattening foods taste so good?
Proteins
44. What element does protein always contain in addition to the three elements found in carbohydrates and
lipids? nitrogen
45. What other two elements are found in select proteins (think cysteine and hemoglobin)? iron
46. What monomers link up to form proteins? amino acids
47. What special proteins have names that end (usually) with the suffix --ase? enzymes
48. Circle and identify the component parts of an amino acid (make sure to explain the significance of the R):
The variable “R” group gives each amino
acid its individual identity
Amino group
Carboxyl group
(makes it acidic)
Single hydrogen atom
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49. What term applies to enzymes because they enable reactions to occur more quickly? catalysts
50. A protein is composed of a string of amino acids linked together. What do you call
this string? A polypeptide chain
51. What kind of bond holds these amino acids together? How is it formed?
A peptide bond, linking the carbon of a carboxyl group in one amino acid to the nitrogen of the amino
group in the next amino acid. It is formed by dehydration synthesis.
52. What do you call the four levels of organization of protein molecules?
Primary, secondary, tertiary, quaternary
53. What are two examples of the secondary structure of protein?
Alpha helix, pleated sheet, and random coil
54. Fibrous protein includes collagen, elastin, silk, and keratin. Which one of these is abundant in skin,
claws, hair, feathers, and hooves? keratin
55. What protein is involved in the transport of oxygen in your bloodstream? hemoglobin
56. What liquid indicator changes color when heated in the presence of protein?
Biuret’s solution (Biuret reagent)
57. What are two membrane proteins found suspended in cell membranes?
What do these two proteins do?
58. What class of proteins transmits messages throughout your body?
hormones
59. Describe the role of insulin, and the cause of type 2 Diabetes:
Nucleic Acids
60. What are the monomers of nucleic acids? nucleotides
61. What are the two principal types of nucleic acids, and where do each reside?
DNA (in the nucleus) and RNA (in the nucleus or cytoplasm, depending on what type of RNA)
62. What are the three components of a nucleotide? (label the diagram)
Phosphate group
Nitrogen base
Deoxyribose sugar
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63. Which particular sugar is part of the DNA molecule? Deoxyribose
64. This sugar is described as a pentose sugar. What does that mean, and why is it specified?
Five sided. It is a different shape than the hexagonal sugars like glucose.
65. What are the four names of the nitrogen bases which comprise the “rungs of the ladder” of the DNA
molecule?
adenine (A), thymine (T), guanine (G), and cytosine (C)
66. How do the nitrogen bases pair up? A with T, and C with G
67. Besides carbon, hydrogen, and oxygen, what other two elements are always found in nucleic acids?
Nitrogen (in the nitrogen bases) and phosphorus (in the phosphate group) The formula of the phosphate
group is PO4
68. Label this little section of DNA:
“rungs”
C
G
sugar
Phosphate group
“siderails”
sugar
Phosphate group
A
T
T
A
Nitrogen bases / base pairs
69. Once this nucleic acid gets long enough, what characteristic and famous shape does it have?
The double helix
70. How many base pairs does your (as a species) particular genome have?
5