AP BIOLOGY FIRST SEMESTER FINAL
EXAM REVIEW
Which four elements make up approximately 96% of living matter? - Correct Answers -
carbon, hydrogen, nitrogen, oxygen
What do cohesion, surface tension, and adhesion have in common with reference to
water? - Correct Answers -all properties related to hydrogen bonding
Why does ice float in liquid water - Correct Answers -Hydrogen bonds stabilize and
keep the molecules of ice farther apart than the water molecules of liquid water.
What makes a substance hydrophobic? - Correct Answers -It has a large area that is
nonpolar, hence no attraction to water
Which property of the carbon atom gives it compatibility with a greater number of
different elements than any other type of atom? - Correct Answers -is able to form 4
single bonds
What is the ultimate source of carbon that is found in organic molecules? - Correct
Answers -The ultimate source of all organic molecules is primary production, in which
photosynthetic organisms take in carbon dioxide gas (or bicarbonate - CO2's water-
dissolved form) and, using sunlight as an energy source, convert it into glucose.
The element nitrogen is present in what types of organic molecules? - Correct Answers
-proteins and nucleic acids
What are polysaccharides made of? - Correct Answers -Polysaccharides are long
chains of monosaccharides linked by glycosidic bonds.
How is the synthesis of polysaccharides, lipids, and proteins similar? - Correct Answers
-They are all synthesized from monomers by dehydration reactions.
Why can humans digest starch but not cellulose? - Correct Answers -humans have
enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta
glycosidic linkages of cellulose
Why do the 20 different amino acids found in polypeptides exhibit different chemical and
physical properties? - Correct Answers -different side chains (R groups)
, What would be a consequence of changing one amino acid in a protein? - Correct
Answers -the biological activity or function, the primary structure of the protein, and the
tertiary structure of the protein might be changed
What is the term used for a change in a protein's three-dimensional shape or
conformation? - Correct Answers -denaturation
What are the components of a nucleotide? - Correct Answers -sugar, phosphate group,
nitrogenous base
What are the structural differences between DNA and RNA? - Correct Answers -DNA is
double stranded and RNA is single stranded
What is the difference between the 5' end vs. 3' end of a polynucleotide strand? -
Correct Answers -A key feature of all nucleic acids is that they have two distinctive
ends: the 5' (5-prime) and 3' (3-prime) ends. This terminology refers to the 5' and 3'
carbons on the sugar. For both DNA (shown above) and RNA, the 5' end bears a
phosphate, and the 3' end a hydroxyl group.
What is the difference between a saturated vs. unsaturated fatty acid? - Correct
Answers -Saturated fatty acids are solid at room temperature, while unsaturated fatty
acids are liquid at room temperature. This is because saturated fats have no double
bond between molecules, which means there are no gaps and the fat is saturated with
hydrogen molecules. On the other hand, unsaturated fats have double bonds, which
break up the chain of hydrogen molecules and create gaps, allowing the fats to liquefy
at room temperature. Unsaturated is better for you
What cell parts differ between a prokaryotic cell vs. a eukaryotic cell? - Correct Answers
-Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while
prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes
include the presence of mitochondria and chloroplasts, the cell wall, and the structure of
chromosomal DNA.
Large numbers of ribosomes are present in cells that specialize in producing what type
of molecules? - Correct Answers -proteins
Which structure is the site of the synthesis of proteins that may be exported from the
cell? - Correct Answers -Endoplasmic reticulum with attached ribosomes is called rough
ER. The attached ribosomes make proteins that will be used inside the cell and proteins
made for export out of the cell. There are also ribosomes attached to the nuclear
envelope.
What is probably the most common route for membrane flow in the endomembrane
system? - Correct Answers -rough ER -> vesicles -> Golgi -> plasma membrane
EXAM REVIEW
Which four elements make up approximately 96% of living matter? - Correct Answers -
carbon, hydrogen, nitrogen, oxygen
What do cohesion, surface tension, and adhesion have in common with reference to
water? - Correct Answers -all properties related to hydrogen bonding
Why does ice float in liquid water - Correct Answers -Hydrogen bonds stabilize and
keep the molecules of ice farther apart than the water molecules of liquid water.
What makes a substance hydrophobic? - Correct Answers -It has a large area that is
nonpolar, hence no attraction to water
Which property of the carbon atom gives it compatibility with a greater number of
different elements than any other type of atom? - Correct Answers -is able to form 4
single bonds
What is the ultimate source of carbon that is found in organic molecules? - Correct
Answers -The ultimate source of all organic molecules is primary production, in which
photosynthetic organisms take in carbon dioxide gas (or bicarbonate - CO2's water-
dissolved form) and, using sunlight as an energy source, convert it into glucose.
The element nitrogen is present in what types of organic molecules? - Correct Answers
-proteins and nucleic acids
What are polysaccharides made of? - Correct Answers -Polysaccharides are long
chains of monosaccharides linked by glycosidic bonds.
How is the synthesis of polysaccharides, lipids, and proteins similar? - Correct Answers
-They are all synthesized from monomers by dehydration reactions.
Why can humans digest starch but not cellulose? - Correct Answers -humans have
enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta
glycosidic linkages of cellulose
Why do the 20 different amino acids found in polypeptides exhibit different chemical and
physical properties? - Correct Answers -different side chains (R groups)
, What would be a consequence of changing one amino acid in a protein? - Correct
Answers -the biological activity or function, the primary structure of the protein, and the
tertiary structure of the protein might be changed
What is the term used for a change in a protein's three-dimensional shape or
conformation? - Correct Answers -denaturation
What are the components of a nucleotide? - Correct Answers -sugar, phosphate group,
nitrogenous base
What are the structural differences between DNA and RNA? - Correct Answers -DNA is
double stranded and RNA is single stranded
What is the difference between the 5' end vs. 3' end of a polynucleotide strand? -
Correct Answers -A key feature of all nucleic acids is that they have two distinctive
ends: the 5' (5-prime) and 3' (3-prime) ends. This terminology refers to the 5' and 3'
carbons on the sugar. For both DNA (shown above) and RNA, the 5' end bears a
phosphate, and the 3' end a hydroxyl group.
What is the difference between a saturated vs. unsaturated fatty acid? - Correct
Answers -Saturated fatty acids are solid at room temperature, while unsaturated fatty
acids are liquid at room temperature. This is because saturated fats have no double
bond between molecules, which means there are no gaps and the fat is saturated with
hydrogen molecules. On the other hand, unsaturated fats have double bonds, which
break up the chain of hydrogen molecules and create gaps, allowing the fats to liquefy
at room temperature. Unsaturated is better for you
What cell parts differ between a prokaryotic cell vs. a eukaryotic cell? - Correct Answers
-Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while
prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes
include the presence of mitochondria and chloroplasts, the cell wall, and the structure of
chromosomal DNA.
Large numbers of ribosomes are present in cells that specialize in producing what type
of molecules? - Correct Answers -proteins
Which structure is the site of the synthesis of proteins that may be exported from the
cell? - Correct Answers -Endoplasmic reticulum with attached ribosomes is called rough
ER. The attached ribosomes make proteins that will be used inside the cell and proteins
made for export out of the cell. There are also ribosomes attached to the nuclear
envelope.
What is probably the most common route for membrane flow in the endomembrane
system? - Correct Answers -rough ER -> vesicles -> Golgi -> plasma membrane
