BIOLOGY EXAM 1 CHAPTERS 1-3
QUESTIONS WITH COMPLETE
SOLUTIONS
Bases - ANSWER-accepts hydrogen and removes them from solution (8-14 on the
pH scale); less hydrogen ions than acidic
Buffers - ANSWER-substances that minimize changes in pH (accept hydrogen ions
when they are in excess and donate hydrogen ions when they are depleted)
Life-supporting properties of water: - ANSWER-hydrogen bonding among water
molecules explains most of water's life-supporting properties; water molecules are
polar (they stick together as a result of hydrogen bonding); cohesion (tendency of
molecules of the same kind to stick together-> attracted to each other); water can
dissolve an enormous variety of solutes necessary for life, providing a medium for
chemical reactions (aqueous environments)
How does structure of water relate to its properties? - ANSWER-all stems from the
hydrogen bonding
What is the importance of water in the cell? - ANSWER-Acts as a solvent for
chemical reactions and also helps transport dissolved compounds into and out of
cells
What is the pH scale? - ANSWER-a measure of the hydrogen concentration in a
substance (7 is neutral; 0-6= acidic; 8-14= basic)
What substances are acidic, basic, and neutral? - ANSWER-Acidic- lemon juice,
battery acid
Basic- bleach, oven cleaner
Neutral- water
Why does carbonic acid form in the ocean?; What is the importance of the ocean
becoming more acidic? - ANSWER-carbonic acid molecules react with a water
molecule to give a bicarbonate ion and a hydronium ion (increasing ocean acidity); it
will affect all wildlife in the ocean and could affect humans if we eat seafood
Denaturation - ANSWER-the alteration of a protein shape through some form of
external stress (ex: heat, acid or alkali), in such a way that it will no longer be able to
carry out its cellular function
Renaturation - ANSWER-reconstruction of a protein or nucleic acid (such as DNA) to
their original form (after denaturation)
What is a functional group? - ANSWER-1. hydroxyl 2. methyl 3. carbonyl 4. carboxyl
5. amino 6. phosphate 7. sulfhydryl
, What are the major macromolecules found in the cell? - ANSWER-1. lipids 2.
carbohydrates 3. proteins 4. nucleic acid
What chemical reaction synthesizes polymer formation? - ANSWER-dehydration
reaction
What chemical reaction breaks down the polymer? - ANSWER-Hydrolysis reaction
Function of each macromolecule: - ANSWER-Carb- fuel (readily available energy)
Lipids- energy storage and hormones
Protein- hormonal, receptive, contractile and motor, structural, defensive, storage
Nucleic Acid- transmission and storage of genetic information
Products - ANSWER-a substance that is formed when 2 or more chemicals react
Reactants - ANSWER-substances that start a chemical reaction
What is the periodic table? - ANSWER-a list of 92 elements in order from lowest
amount of protons to greatest
What elements are most prevalent in the human body? - ANSWER-1. nitrogen 2.
oxygen 3. carbon 4. hydrogen
What are trace elements? - ANSWER-only need a small amount of them to thrive;
they are important because they are vital for maintaining health
What are specific examples of the importance of trace elements in the human body?
- ANSWER-Iodine- goiter will occur if not enough iodine; fluorine- maintain healthy
bones and teeth (found in dental products and water)
What are the major bonds in biological molecules? - ANSWER-1. non-covalent
(hydrogen bond, ionic bond, hydrophobic, hydrophilic, and Van der Waals)
2. covalent (polar and non-polar)
Covalent bonds - ANSWER-takes a lot of effort to break the bond; forms when 2
atoms share one or more pairs of electrons (very strong)
Non-covalent bonds - ANSWER-easily broken bond; forms when 2 atoms are
attracted to 1 or more pairs of electrons (weak); requires less energy to break
Hydrogen bond - ANSWER-partial positive charge and partial negative charge
Van der Waals - ANSWER-happens when molecules are certain distances from
each other (not too close or too far apart); occurs between polar and non polar
molecules and intermolecular forces
What is the role of molecule structure and function? - ANSWER-Structure dictates
function
QUESTIONS WITH COMPLETE
SOLUTIONS
Bases - ANSWER-accepts hydrogen and removes them from solution (8-14 on the
pH scale); less hydrogen ions than acidic
Buffers - ANSWER-substances that minimize changes in pH (accept hydrogen ions
when they are in excess and donate hydrogen ions when they are depleted)
Life-supporting properties of water: - ANSWER-hydrogen bonding among water
molecules explains most of water's life-supporting properties; water molecules are
polar (they stick together as a result of hydrogen bonding); cohesion (tendency of
molecules of the same kind to stick together-> attracted to each other); water can
dissolve an enormous variety of solutes necessary for life, providing a medium for
chemical reactions (aqueous environments)
How does structure of water relate to its properties? - ANSWER-all stems from the
hydrogen bonding
What is the importance of water in the cell? - ANSWER-Acts as a solvent for
chemical reactions and also helps transport dissolved compounds into and out of
cells
What is the pH scale? - ANSWER-a measure of the hydrogen concentration in a
substance (7 is neutral; 0-6= acidic; 8-14= basic)
What substances are acidic, basic, and neutral? - ANSWER-Acidic- lemon juice,
battery acid
Basic- bleach, oven cleaner
Neutral- water
Why does carbonic acid form in the ocean?; What is the importance of the ocean
becoming more acidic? - ANSWER-carbonic acid molecules react with a water
molecule to give a bicarbonate ion and a hydronium ion (increasing ocean acidity); it
will affect all wildlife in the ocean and could affect humans if we eat seafood
Denaturation - ANSWER-the alteration of a protein shape through some form of
external stress (ex: heat, acid or alkali), in such a way that it will no longer be able to
carry out its cellular function
Renaturation - ANSWER-reconstruction of a protein or nucleic acid (such as DNA) to
their original form (after denaturation)
What is a functional group? - ANSWER-1. hydroxyl 2. methyl 3. carbonyl 4. carboxyl
5. amino 6. phosphate 7. sulfhydryl
, What are the major macromolecules found in the cell? - ANSWER-1. lipids 2.
carbohydrates 3. proteins 4. nucleic acid
What chemical reaction synthesizes polymer formation? - ANSWER-dehydration
reaction
What chemical reaction breaks down the polymer? - ANSWER-Hydrolysis reaction
Function of each macromolecule: - ANSWER-Carb- fuel (readily available energy)
Lipids- energy storage and hormones
Protein- hormonal, receptive, contractile and motor, structural, defensive, storage
Nucleic Acid- transmission and storage of genetic information
Products - ANSWER-a substance that is formed when 2 or more chemicals react
Reactants - ANSWER-substances that start a chemical reaction
What is the periodic table? - ANSWER-a list of 92 elements in order from lowest
amount of protons to greatest
What elements are most prevalent in the human body? - ANSWER-1. nitrogen 2.
oxygen 3. carbon 4. hydrogen
What are trace elements? - ANSWER-only need a small amount of them to thrive;
they are important because they are vital for maintaining health
What are specific examples of the importance of trace elements in the human body?
- ANSWER-Iodine- goiter will occur if not enough iodine; fluorine- maintain healthy
bones and teeth (found in dental products and water)
What are the major bonds in biological molecules? - ANSWER-1. non-covalent
(hydrogen bond, ionic bond, hydrophobic, hydrophilic, and Van der Waals)
2. covalent (polar and non-polar)
Covalent bonds - ANSWER-takes a lot of effort to break the bond; forms when 2
atoms share one or more pairs of electrons (very strong)
Non-covalent bonds - ANSWER-easily broken bond; forms when 2 atoms are
attracted to 1 or more pairs of electrons (weak); requires less energy to break
Hydrogen bond - ANSWER-partial positive charge and partial negative charge
Van der Waals - ANSWER-happens when molecules are certain distances from
each other (not too close or too far apart); occurs between polar and non polar
molecules and intermolecular forces
What is the role of molecule structure and function? - ANSWER-Structure dictates
function
