Download Biomolecules review with answers

Biomolecule Unit Review Notes
1. What are elements? Made up of the same atoms
2. What is an atom? Smallest unit of matter
3. Identify the three parts of an atom. Indicate where they are found in an atom, and the charge on each.
a. Proton
b. Neutron
c. Electron
4. What is CHNOPS, and why is it important? Carbon, Hydrogen, Nitrogen, Oxygen, Potassium, Sulfur.
The five most common elements in the human body.
5.
What are valence electrons? Why are they important? The outermost electrons used in bonding
6. What is an ion? How can an atom become an ion? An atom with more or less electrons.
7. Explain how an ionic bond forms. An electron is added or taken away.
8. Explain how a covalent bond forms. Electrons are shared
9. Explain how a polar covalent bond is different from a nonpolar covalent bond. A polar bond has an
uneven charge. A water molecule will have a slight negative charge on the oxygen and a slight
positive charge on the hydrogen. A non polar covalent bond does not have this.
10. Explain how hydrogen bonds form. Identify 3 places hydrogen bonds are found in living things
a. Water and evaporative cooling
b. DNA
c. Folding or proteins
11. Define the terms hydrophobic and hydrophilic. Hydrophobic is water hating, phallic is water loving.
12. What is an acid? Give up more H+ ions
13. What is a base? Gives up more OH- ions
14.
What is measured by the pH scale? pH is the negative log of the H+ concentration in mol/L in any
medium.
15. Describe the pH scale. Measures from 1-14. 1-6.9 acidic, 7.1-14 basic
Bill and Ted are two most triumphant biology students. They measure the pH of tomato juice as 4, the pH of
grapefruit juice as 3 and the pH of lemon juice as 2.
16. Are these substances acids or bases? Acids
17.
How much stronger is grapefruit juice than tomato juice? 10 x
18.
How much stronger is lemon juice than tomato juice? 100 x
19. What are organic molecules? Contain carbon
What element makes up the backbone of all of the biological molecules? Below your answer list 2 characteristics
of this molecule that make it suitable to build biomolecules.
20. Element: Carbon
21. Characteristics:
a. Covalent bonds (valence electrons)
b. Highly unreactive
22. What is the relationship between polymers and monomers? Polymers are made of monomers
23. Explain what occurs during a condensation reaction. Monomers are joined to form polymers.
(Dehydration reaction because there is a formation of a water molecule as a result.
24. Explain what occurs during hydrolysis. Polymers are broken down into smaller units with the
addition of water.
25. What is the relationship between hydrogen and oxygen in carbohydrates? Most carbohydrates have a
ratio of 1:2:1 of carbon, hydrogen, and oxygen
Complete the chart below:
Biomolecule
Elements
Carbon
Oxygen
Carbohydrate
Hydrogen
Lipid
Protein
Nucleic Acid
Carbon
Oxygen
Hydrogen
Nitrogen
Phosphorus
Carbon
Oxygen
Hydrogen
Nitrogen
Sulfur
Carbon
Oxygen
Hydrogen
Nitrogen
Phosphorus
Monomer
Sugar
C6H12O6
Polymer
Starch
Cellulose
Chitin
Glycogen
Energy storage
Structural
Phospholipids
Cholesterol
Cell membrane
Energy storage
Amino acids
Proteins
Signaling
Energy storage
Structural
Sugar (ribose
or
deoxyribose)
Phosphate
Nitrogen base
DNA
RNA
mRNA
tRNA
rRNA
Genetic and
protein
information
Fatty acids:
glycol
26. Identify the function of each of the following carbohydrates
a. glucose: energy and monomer of polysaccharides
b. glycogen: energy store in the liver
c. starch: energy from polysaccharide
d. cellulose: structure and support
e. chitin: protection
Function of
Polymer
Other Info
Saturated
Unsaturated
27. Imagine that you eat a large meal containing lots of starch. Explain what happens to the starch during
digestion and how your body would use the digested starch? Starch is broken down into smaller
molecules used for energy during respiration.
28. How are starch and glycogen the same? How are they different? Both are polymers of sugars. Starch
is a long and sometimes slight branched chain of sugars. Glycogen is high branched.
29. How are starch and cellulose the same? How are they different? Both are polymers of sugar. Starch is
soluble in water, cellulose is not, and cellulose is highly branched and structural in plants and
not in humans.
30. Fats, oils, cholesterol and steroids all belong to what class of biomolecule? Lipids
31. One basic property of lipids is that they are hydrophobic. What does this mean? Do not attract water.
32. How do living things use fats and oils? Energy, insulation, organ cushioning, hormones
33. What is the difference between saturated and unsaturated fatty acids? Saturated fats have all the bonds
filled with single bonds to hydrogen, Unsaturated have some double bonds = less hydrogen.
34. How do phospholipids differ from triglycerides? Phospholipids contain three phosphate groups
between the fatty acids and the glycerol; Triglycerides get their name from three fatty acids
joined together.
35. How do living things use phospholipids? Cell membranes
36. How do livings things use cholesterol? Cell membranes, estrogen, testosterone, Vitamin D
37. Explain the relationship between amino acids, protein shape and protein function. Amino acids are the
monomers of proteins joined by peptide bonds. There are twenty Amino Acids to produce all
proteins. Protein shapes fall into 4 categories: Primary is straight, Secondary is twisted and
folded into sheets and helices, Tertiary is a complex inter linking for chains, and Quaternary
which is the noncovalent binding of multiple tertiary complexes.
38. How do living things use steroids? Estrogen, progesterone, and testosterone. Common steroid is
cholesterol. Steroids are characterized by having a carbon skeleton with four fused rings.
39. Enzymes are what type of biomolecule? Enzymes are proteins that speed up reactions.
40. What is the relationship between enzymes and activation energy? Lower the amount of activation
energy needed and thus speed up the reaction.
41. Why is the shape of an enzyme important? 1) substrates have a particular shape and fit into an
active site on the enzyme which must also have a particular shape; 2) most enzymes consist of
several proteins that fit together in a very precise way.
42. Explain each term below and how it relates to enzymes
a. active site: Site on enzyme that attaches to the target molecule (Substrate)
b. substrate: Target molecules often called reactants
c. products: End result of target molecule released from the active site. Enzyme is
unchanged
43. How many different types of substrate can an enzyme work with? Use your knowledge of enzyme structure
and function to explain why this is so. Only one specific substrate the enzyme is unchanged so it
can continue to work.
44. Examine the equation below. It represents a chemical reaction that has been catalyzed by an enzyme.
Identify the substrate, enzyme and products. Explain what is meant by ES
.
Catalase + 2H2O2
ES
Catalase + 2H2O + O2
ES: enzyme-substrate complex
Substrate: H2O2
Enzyme: Catalase (ase ending)
Products: 2H2O + O2
45. What happens to a protein that is denatured? Denaturation of proteins involves the disruption and
possible destruction of both the secondary and tertiary structures
46. What are two factors that can denature a protein? Temperature and pH
47. What are enzyme inhibitors? a molecule which binds to enzymes and decreases their activity.
48. What occurs during competitive inhibition? a molecule similar to the substrate but unable to be
acted on by the enzyme competes with the substrate for the active site
49. Explain how the lock and key model of enzyme action differs from the induced fit model. Lock and key is
specific, one enzyme one substrate. Induced fit states the substrate plays a role in determining
the final shape of the enzyme and that the enzyme is partially flexible
50. Ribose, glucose and maltose are what type of molecules? How do you know? Simple Sugars: (ose ending)
51. Lactase, maltase and diastase are what type of molecule? How do you know? Enzymes to break down
specifc sugars. (ase ending)
52. What are four nucleic acids. Explain what each is used for.
a. DNA (genetic code in cell, master set of directions found in nucleus) Double helix
b. mRNA: Carries codon out of nucleus
c. tRNA: Carries appropriate amino acid to peptide chain
d. rRNA: Site of polypeptide synthesis
Nucleic acid structure:
 Nitrogen-containing bases
the purines: adenine and guanine
the pyrimidines: cytosine, thymine (only in DNA), and uracil (only in RNA)
 Ribose (in RNA) or deoxyribose (in DNA) sugars
 Phosphate (linked to the sugars to form diesters)
53. What is the relationship between DNA and protein? DNA codes for a specific protein
54. What is the relationship between DNA and RNA? RNA takes the complementary code out of the
nucleus
55. What is the relationship between ATP and ADP? ATP is Adenosine-5'-triphosphate a nucleoside
triphosphate used in cells as a coenzyme. The energy currency of the cell. ADP is Adenosine5'-diphosphate which can be dehydrated with a phosphate group to become ATP.