The chemical properties of atoms are largely a function of the number of ______. |
c. electrons in the valence shell |
The electrically neutral chemical bond holding the sodium ion () and chloride ion () together in a sodium chloride molecule is a/an: |
c. ionic bond. |
Which basic type of chemical reaction is expressed by the formula: ? |
a. Exchange reaction |
How does the hydrogen ion concentration ([]) of lemon juice (pH 2) compare to the [] of urine (pH 6)? |
b. Lemon juice has a ten thousand times higher concentration of hydrogen ions than urine. |
Water is an excellent solvent, as well as a reactant or product in many chemical reactions; this is due to ________. |
d. the polarity of water |
Which statement accurately describes the two strands in the DNA double helix? |
d. The two strands are complementary and antiparallel. |
Regarding organic compounds, which functional group is found in bacterial and eukaryotic plasma membranes? |
d. Ester group |
Which level of protein structure is defined by the localized, repetitious twisting or folding of the polypeptide chain into helices and pleated sheets? |
c. Secondary structure |
Which of the following statements is true regarding organic molecules? |
b. All steroids are lipids. |
What is responsible for the "backbone" of the double helix of DNA? |
b. A repeating sugar-phosphate combination |
Regarding the structure of simple lipids such as oleic acid, a cis fatty acid, the bond between the glycerol molecule and each fatty acid is called a/an ______. |
d. ester linkage |
The formation of the disaccharide sucrose (C12H22O11) from the monosaccharides glucose (C6H12O6) and fructose (C6H12O6) occurs via which process? |
a. Dehydration synthesis |
Regarding the general structural formula for amino acids, which of the following is not a structural component of an amino acid? |
a. An ether group (CH2-O-CH2) |
What type of bond holds the double strands of DNA together? |
a. Hydrogen bonds |
In a double-stranded molecule of DNA, which nucleotides are paired with one another? |
a. Guanine and cytosine |
Which of the following is not found in DNA? |
d. Adenosine |
An E. coli culture that has been growing at 37°C is moved to 25°C. Which of the following changes must be made in its plasma membrane? |
d. The number of unsaturated chains must increase. |
Identify the following reaction: H2O + CO2 ↔ H2CO3 |
c. Exchange reaction |
What is the type of bond holding hydrogen and oxygen atoms in the H2O molecule? |
c. Covalent bond |
Identify the following reaction: NH4OH ↔ NH3 + H2O |
a. Reversible reaction |
Two glucose molecules are combined to make a maltose molecule. What is the chemical formula for maltose? |
d. C12H22O11 |
Antacids neutralize acid by the following reaction. Identify the salt. |
c. MgCl2 |
Identify the following reaction: Sucrose + H2O → Glucose + Fructose |
b. Hydrolysis reaction |
The antimicrobial drug imidazole inhibits sterol synthesis. This would most likely interfere with |
a. Eukaryotic plasma membranes. |
Desulfovibrio bacteria can perform the following reaction: S6- → S2-. These bacteria are |
a. Oxidizing sulfur. |
What is the type of bond between the hydrogen of one molecule and the nitrogen of another molecule? |
b. Hydrogen bond |
Structurally, ATP is most like which type of molecule? |
a. Nucleic acid |
Which of the following is a base? |
b. NaOH → Na+ + OH- |
Oil-degrading bacteria are naturally present in the environment but cannot degrade an oil spill fast enough to avoid ecological damage. How can the actions of these bacteria be sped up? |
e. Provide nitrogen and phosphorus. |
Which type of molecule contains -NH2 groups? |
b. Protein |
Identify the following reaction: Lactose + H2O → Glucose + Galactose |
c. Hydrolysis reaction |
Which type of molecule contains the alcohol glycerol? |
b. Lipid |
Identify the following reaction: Glucose + Fructose → Sucrose + Water |
e. Dehydration synthesis reaction |
What is the type of bond between carbon, hydrogen, and oxygen atoms in organic molecules? |
a. Covalent bond |
Which of the following is the type of bond between molecules of water in a beaker of water? |
b. Hydrogen bond |
Which are the primary molecules making up plasma membranes in cells? |
d. Lipids |
What do genes consist of? |
a. Nucleic acids |
Starch, dextran, glycogen, and cellulose are polymers of |
a. Glucose. |
Which of the following is the type of bond holding K+ and I- ions in KI? |
c. Ionic bond |
What is the type of bond between ions in salt? |
b. Ionic bond |
Which molecule is composed of a chain of amino acids? |
a. Protein |