BS -GI SYSTEM II
1. What is the difference in the bonding between alpha-helix and beta sheets? -
ANSWER Hydrogen bonding occurs between the amides of adjacent chains
in the sheets instead of between the amides in different parts of the helices.
2. Organic molecules have a carbon backbone and _____ such as -OH and -
NH2 that can form hydrogen bonds - ANSWER functional groups
3. Phospholipids are made up of: - ANSWER a phosphate, two fatty acids and
a glycerol.
4. Proteins are polymers formed of structural units called: - ANSWER amino
acids.
5. Proteins are created with: - ANSWER peptide bonds.
6. The covalent bonds connecting monomer units in sugars can be formed by
the removal of a water molecule. This reaction is referred to as: - ANSWER
a dehydration reaction.
7. Common lipids for energy storage are: - ANSWER triglycerides.
8. A DNA strand contains 20 purines and 26 pyrimidines. How many purines
will the complementary strand contain? - ANSWER 26
,9. α - glucose is present in potatoes and β - glucose is present in wood. Both
are glucose molecules but one can be used by humans to synthesize ATP and
one cannot. Based on this information, what is the best explanation on why
humans can only digest one of the glucose types? - ANSWER α - glucose
and β - glucose are stereoisomers with OH groups oriented differently.
10.Egg whites consist primarily of water and the protein albumin. When you fry
an egg, why does the egg white turn from clear to white? - ANSWER The
protein becomes denatured.
11.Which chemical group forms hydrogen bonds with water and is most likely
to explain why sugars dissolve well in water? - ANSWER -O-H
12.Atoms of a single element that possess different numbers of neutrons are
called: - ANSWER isotopes.
13.An atom has 20 electrons and 20 neutrons. What is the mass of this atom? -
ANSWER 40
14.The reaction (H2 + F2 → 2HF) is an example of a redox reaction. In reality,
two half reactions are occurring. The half reaction (H2 → 2H+ + 2e-) is a(n):
- ANSWER oxidation reaction
15.In the crystal matrix of ordinary salt, the sodium and chlorine are held
together by: - ANSWER ionic bonds.
, 16.Water molecules are attracted to each other due to the opposite charges
created by partial charge separations within the molecules. These attractions
are called: - ANSWER hydrogen bonds.
17.The negative logarithm of the hydrogen ion concentration in the solution is
referred to as: - ANSWER pH
18.A chemist adds a chemical to pure water and there is a 100 fold increase in
the concentration of hydrogen ions. What is the best approximation of the
new pH value? - ANSWER 5
19.Water is most dense and thus heaviest at 4oC. At 0oC, ice forms and can
float on liquid water. Suppose ice were most dense at 0oC. What would
happen in a lake? - ANSWER The ice would cover the bottom of the aquatic
system and would build up in layers over time.
20.The accumulation of amino acids and sugars in animal cells can occur
through - ANSWER coupled transport.
21.Incubation of cells at 20°C blocks the release of proteins from the trans-
Golgi. Under such conditions, you would expect to see - ANSWER a
decrease in exocytosis.
22.The organelle that can collect, package, modify, and transport molecules is
called the: - ANSWER Golgi apparatus.
1. What is the difference in the bonding between alpha-helix and beta sheets? -
ANSWER Hydrogen bonding occurs between the amides of adjacent chains
in the sheets instead of between the amides in different parts of the helices.
2. Organic molecules have a carbon backbone and _____ such as -OH and -
NH2 that can form hydrogen bonds - ANSWER functional groups
3. Phospholipids are made up of: - ANSWER a phosphate, two fatty acids and
a glycerol.
4. Proteins are polymers formed of structural units called: - ANSWER amino
acids.
5. Proteins are created with: - ANSWER peptide bonds.
6. The covalent bonds connecting monomer units in sugars can be formed by
the removal of a water molecule. This reaction is referred to as: - ANSWER
a dehydration reaction.
7. Common lipids for energy storage are: - ANSWER triglycerides.
8. A DNA strand contains 20 purines and 26 pyrimidines. How many purines
will the complementary strand contain? - ANSWER 26
,9. α - glucose is present in potatoes and β - glucose is present in wood. Both
are glucose molecules but one can be used by humans to synthesize ATP and
one cannot. Based on this information, what is the best explanation on why
humans can only digest one of the glucose types? - ANSWER α - glucose
and β - glucose are stereoisomers with OH groups oriented differently.
10.Egg whites consist primarily of water and the protein albumin. When you fry
an egg, why does the egg white turn from clear to white? - ANSWER The
protein becomes denatured.
11.Which chemical group forms hydrogen bonds with water and is most likely
to explain why sugars dissolve well in water? - ANSWER -O-H
12.Atoms of a single element that possess different numbers of neutrons are
called: - ANSWER isotopes.
13.An atom has 20 electrons and 20 neutrons. What is the mass of this atom? -
ANSWER 40
14.The reaction (H2 + F2 → 2HF) is an example of a redox reaction. In reality,
two half reactions are occurring. The half reaction (H2 → 2H+ + 2e-) is a(n):
- ANSWER oxidation reaction
15.In the crystal matrix of ordinary salt, the sodium and chlorine are held
together by: - ANSWER ionic bonds.
, 16.Water molecules are attracted to each other due to the opposite charges
created by partial charge separations within the molecules. These attractions
are called: - ANSWER hydrogen bonds.
17.The negative logarithm of the hydrogen ion concentration in the solution is
referred to as: - ANSWER pH
18.A chemist adds a chemical to pure water and there is a 100 fold increase in
the concentration of hydrogen ions. What is the best approximation of the
new pH value? - ANSWER 5
19.Water is most dense and thus heaviest at 4oC. At 0oC, ice forms and can
float on liquid water. Suppose ice were most dense at 0oC. What would
happen in a lake? - ANSWER The ice would cover the bottom of the aquatic
system and would build up in layers over time.
20.The accumulation of amino acids and sugars in animal cells can occur
through - ANSWER coupled transport.
21.Incubation of cells at 20°C blocks the release of proteins from the trans-
Golgi. Under such conditions, you would expect to see - ANSWER a
decrease in exocytosis.
22.The organelle that can collect, package, modify, and transport molecules is
called the: - ANSWER Golgi apparatus.
