Download EXAM 1 LINK

Biochemistry: REVIEW
1) About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25
elements make up approximately 96% of living matter?
2) Why is each element unique and different from other elements with respect to its chemical
properties?
3) What are two differences between carbon-12 (
C) and carbon-14 (
C)?
4) A covalent chemical bond is one in which ……..
5) What results from an unequal sharing of electrons between atoms?
6) When is a covalent bond is likely to be polar?
7) Which bond or interaction would be difficult to disrupt when compounds are put into water?
8) What are Van der Waals interactions?
9) What bonding or interaction is most likely to occur among a broad array of molecules of
various types (polar, nonpolar, hydrophilic, hydrophobic)?
10) What is the maximum number of hydrogen atoms that can be covalently bonded in a
molecule containing two carbon atoms?
11) Describe chemical equilibrium.
12) What is the attraction of water molecules to one another called?
13) If a salamander relied on hydrogen bonds to cling to surfaces, describe the surface would
cause the most problems for this animal?
14) In a single molecule of water, how are the two hydrogen atoms are bonded to a single
oxygen atom?
15) The slight negative charge at one end of one water molecule is attracted to the slight positive
charge of another water molecule. What is this attraction called?
16) The partial negative charge in a molecule of water occurs because…..
17) What type of molecules can water molecules form hydrogen bonds with?
18) Water has a high specific heat. Explain.
19) Which type of bond must be broken for water to vaporize?
20) Why does ice float in liquid water?
1
21) What is a buffer solution?
22) How do buffers help resist shifts in pH?
23) What elements are present in all organic molecules?
24) How can you account for the complexity and variety of organic molecules?
25) What type of bonds does a carbon atom most likely to form with other atoms?
26) Which two functional groups are always found in amino acids?
27) Amino acids in water are amphoteric. Explain.
28) What is the chemical reaction mechanism by which cells make polymers from monomers?
29) How many molecules of water are needed to completely hydrolyze a polymer that is 11
monomers long?
30) Summarize the relationship between dehydration reactions and hydrolysis.
31) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a
molecule made by linking three glucose molecules together by dehydration reactions?
32) Why are hydrocarbons insoluble in water?
33) There are 20 different amino acids. What makes one amino acid different from another?
34) Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How
many peptide bonds are present in this protein?
35) Which bonds are created during the formation of the primary structure of a protein?
36) What maintains the secondary structure of a protein?
37) Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins?
38) What type of covalent bond between amino acid side chains (R groups) functions in
maintaining a polypeptide's specific three-dimensional shape?
39) At which level(s) of protein structure are interactions between the side chains (R groups)
most important?
40) The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain
of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino
acids in a globular protein in aqueous solution? (Hint: facing outward into the cytoplasm or
facing towards the interior of the protein).
2
41) What is the primary function of DNA and RNA molecules?
42) What are the components of nucleotides of DNA? RNA?
43) What are the structural differences between DNA and RNA?
44) Matching:
Carboxyl
Amine
Alcohol
Thiol
Carbonyl
Acid
Base
Polar
Nonpolar
__
__
__
__
__
__
__
__
__
3
45) Matching:
Carbohydrate
Lipid
Amino acid
Fatty acid
Cholesterol
Monosaccharide
Glycerol
__
__
__
__
__
__
__
A
B
C
D
4
E
F
46) A chemist wishes to make an organic molecule less acidic. What functional groups should be
added to the molecule in order to do so?
Use the following information to answer the question below.
47) Approximately 32 different monomeric carbohydrate subunits are found in various natural
polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each
synthesized from four nucleotides.
Which class of biological polymer has the greatest functional variety and why? Provide a
mathematical example supporting your claim.
48) How do saturated and unsaturated fats compare structurally?
49) What structural level of a protein least affected by a disruption in hydrogen bonding?
50) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a
polymer made by linking ten glucose molecules together by dehydration reactions?
5