Biology Ch.2 Practice Test
The shape of the enzyme is essential for binding the two substrates and positioning them properly to react and form carbonic acid. Change to the shape therefore reduce the effectiveness of the enzyme.
Carbonic anhydrase is found in the bloodstream of the human body. The bloodstream is usually at a temperature of 37°C. How might an increase in a person's body temperature affect the function of carbonic anhydrase and other enzymes in the body? Be sure to explain any effects on the enzyme itself and the reaction that it catalyzes. The __________ of the enzyme is essential for binding the two ____________ and positioning them properly to ______ and form carbonic acid. Change to the ________ therefore __________ the _________________ of the enzyme.
The solution is basic (meaning it has fewer H+ ions than OH- ions)
Household bleach has a pH between 12 and 13. From this information, which of the following BEST describes the bleach solution? The solution is ________
the presence of amino groups and carboxyl groups allow any combination of amino acids to join together to form a polypeptide. The R groups differ among amino acids, and they determine the properties of the polypeptide or protein.
How do both the similarity and differences among amino acids allow them to form macromolecules with a wide variety of properties? the presence of __________ groups and ___________ groups allow any combination of amino acids to join together to form a ______________. The ___ groups differ among amino acids, and they determine the ______________ of the polypeptide or ___________.
Water is a polar molecule, meaning it has a positive and negative end. The polarity allows multiple hydrogen bonds to form among adjacent water molecules. The hydrogen bonds attract water molecules to one another, and account for the ability of water molecules to adhere, or stick together, such as by forming beads.
How does the structure of the water molecule help explain the ability of water to form beads on the wax? Water is a _________ molecule, meaning it has a ____________ and ____________ end. The ___________ allows multiple ____________ bonds to form among adjacent ________ molecules. The ____________ bonds attract ________ molecules to one another, and account for the ability of _______ molecules to adhere, or ______ ________, such as by forming beads.
Buffers prevent small amounts of acid or base from changing the pH of blood
Human blood has a pH of 7.4. How do buffers in the blood affect the pH? Buffers prevent ________ amounts of ______ or base from ____________ the ____ of blood.
the rearrangement of electrons to break or form chemical bonds
In a chemical reaction, which event ALWAYS occurs as the reaction proceeds? the rearrangement of _________ to break and form ____________ _______
the chemical structure of the R group in the molecule
Several different amino acids join together to form a protein. How do any two types of amino acids differ from one another? the ___________ structure of the __ group in the molecule
very different
The elements sodium and chlorine react to form the chemical compound sodium chloride. How would you predict the properties of sodium chloride compare with those of its constituent elements? very _____________
It decreases the activation energy
The enzyme carbonic anhydrase is a protein that binds to two small molecules: water and carbon dioxide. By holding the two molecules in the proper position, the enzyme allows the two molecules to react to form a product, carbonic acid. The enzyme then releases the product and becomes available to catalyze the same reaction once again. How does carbonic anhydrase change the reaction between carbon dioxide and water? it ________________ the _____________ _______
covalent bonds (formed by shared electrons between atoms)
What allows the three atoms in a water molecule to stay together? _______________ bonds
Starch is a polymer made of glucose monomers
What best describes the relationship between starch and glucose? ________ is a _________ made of ___________ ___________
Move the protons and neutrons to a small space in the center
What change to Hobie's model of a carbon atom would improve its accuracy? move the __________ and ___________ to a small space in the __________
the gain or loss of one or more electrons
What event changes an atom into an ion? the gain or loss of one or more _____________
Enzymes decrease the activation energy of the reaction
What is the effect of an enzyme on the energy of a chemical reaction? Enzymes ____________ the ______________ ________ of the reaction.
polarity (O is negative, H is positive)
What property of a water molecule allows hydrogen bonds to form among adjacent molecules? _____________
a long chain made only of carbon and hydrogen atoms
Which of these molecular structures could be found in a lipid, but not in a carbohydrate, protein, or nucleic acid? a long chain made only of ___________ and ______________ atoms
protons, electrons
Which two types of particles are present in equal numbers in an atom, but not in an ion? ____________, _____________
nucleic acid
Which type of macromolecule has the function of storing and transmitting hereditary or genetic information? ____________ ____
c. (11 protons, 13 neutrons, and 11 electrons)
A scientist is studying two isotopes of sodium, labeled A and B. In Isotope A, each of the atoms has 11 protons, 12 neutrons, and 11 electrons. What could be the atomic structure of Isotope B? A. 11 protons, 12 neutrons, and 10 electrons B. 12 protons, 12 neutrons, and 11 electrons C. 11 protons, 13 neutrons, and 11 electrons D. 11 protons, 12 neutrons, and 12 electrons
Lipid molecules are nonpolar because they repel water molecules, which are polar
A teacher assigns the following experiment to a class. Draw an outline of a bird's feather, and color one half of the outline with a thick coat from a wax crayon. Leave the other half uncolored. Next, sprinkle a few drops of water on both halves of the feather. You will observe that the water soaks into the plain paper. The waxy coat, however, allows the paper to remain dry. Water forms tiny beads on top of the wax instead of soaking through it. The results of the experiment MOST STRONGLY support which conclusion about the polarity of lipid molecules? Lipid molecules are __________ because they ______ water molecules, which are _______
forming a waterproof covering on feathers, leaves, and fruits
A teacher assigns the following experiment to a class. Draw an outline of a bird's feather, and color one half of the outline with a thick coat from a wax crayon. Leave the other half uncolored. Next, sprinkle a few drops of water on both halves of the feather. You will observe that the water soaks into the plain paper. The waxy coat, however, allows the paper to remain dry. Water forms tiny beads on top of the wax instead of soaking through it. The results of the experiment are MOST USEFUL for explaining which of these functions of lipids in organisms? forming a ___________ _____________ on feathers, leaves, and fruits
a protein that specifically binds lipids or oils
A team of scientists and engineers is working together to develop a new cleaning product. The team has identified a species of bacteria that gets energy by breaking apart lipids and oils. The team wants to isolate the key substance that the bacteria use for this process, and then adapt the substance for the new cleaning product. Which macromolecule should the team try to isolate from the bacteria? a __________ that specifically binds ______ or _______
an amino group and a carboxyl group
Amino acids are named after two of their functional groups: the amino group (NH2), which acts like a base, and the carboxyl group (COOH), which acts like an acid. Amino acids also contain a third functional group, often called the R group. In alanine, the R group is a methyl group (CH3). In serine, the R group is a methyl alcohol (-CH2OH). What functional groups will be joined together if alanine and serine molecules combine to form a single molecule? an __________ group and a ___________ group
peptide, water, protein
Amino acids are named after two of their functional groups: the amino group (NH2), which acts like a base, and the carboxyl group (COOH), which acts like an acid. Amino acids also contain a third functional group, often called the R group. In alanine, the R group is a methyl group (CH3). In serine, the R group is a methyl alcohol (-CH2OH). Two amino acids unite by forming a ___________ bond between them and releasing a molecule of ________. The union of many amino acids forms a macromolecule called a __________
