microbiology chapter 2

Answer: FALSE

1) Elements only achieve the full complement of electrons in outermost energy cells by donating away or sharing electrons.

B) It has 12 neutrons in its nucleus

1) Which of the following statements about the atom C is FALSE? A) It has 6 protons in its nucleus. B) It has 12 neutrons in its nucleus. C) It has 6 electrons orbiting the nucleus. D) Its atomic number is 6. E) Its atomic weight is 12.

Answer: FALSE

10) Any compound that contains carbon is considered to be strictly organic.

C) exchange reaction

10) Identify the following reaction: HCl + NaHCO3 --> NaCl + H2CO3 A) dehydration synthesis reaction B) hydrolysis reaction C) exchange reaction D) reversible reaction E) ionic reaction

D) reversible reaction

11) Identify the following reaction: NH4OH ⇌ NH3 + H2O A) dehydration synthesis reaction B) hydrolysis reaction C) exchange reaction D) reversible reaction E) ionic reaction

B) phospholipids

12) Which type of molecule contains the alcohol glycerol? A) carbohydrate B) phospholipids C) DNA D) protein

A) carbohydrate

13) Which type of molecule is composed of (CH2O) units? A) carbohydrate B) lipid C) nucleic acid D) protein

D) protein

14) Which type of molecule contains -NH2 (amino) groups? A) carbohydrate B) triglycerides C) nucleic acid D) protein

A) triglycerides

15) Which type of molecule NEVER contains a phosphate group? A) triglycerides B) phospholipid C) nucleic acid D) ATP

B) two

16) Based upon the valence numbers of the elements magnesium (2) and hydrogen (1), predict how many covalent bonds would form between these atoms to achieve the full complement of electrons in their outermost energy shells. A) one B) two C) three D) four

B) 2

17) Table 2.1 O C H Using the information in Table 2.1, calculate the number of moles in 92 grams of ethanol, C2H5OH. A) 1 B) 2 C) 3 D) 4 E) The answer cannot be determined.

C) Tertiary structures are formed only from covalent bonds.

18) Which of the following statements regarding protein structure is FALSE? A) The primary structure is formed by covalent bonding between amino acid subunits. B) Secondary structures are formed only from hydrogen bonds. C) Tertiary structures are formed only from covalent bonds. D) Quaternary structures involved multiple polypeptides.

D) KH2PO4 K+ + H2PO4 acid

19) Which of the following pairs is mismatched? A) NaOH Na+ + OH base B) HF H+ + F acid C) MgSO4 Mg2+ + SO42- salt D) KH2PO4 K+ + H2PO4 acid E) H2SO4 2H+ + SO42- acid

Answer: FALSE

2) Covalent bonds are always shared equally.

A) They are exchange reactions.

20) Table 2.2 NaOH ⇌ Na+ + OH- base HF ⇌ H+ + F- - acid MgSO4 ⇌ Mg2+ + SO42- salt KH2PO4 ⇌ K+ + H2PO4- acid H2SO4 ⇌ 2H+ + SO42- salt Which of the following statements about the reactions in Table 2.2 is FALSE? A) They are exchange reactions. B) They are ionization reactions. C) They occur when the reactants are dissolved in water. D) They are dissociation reactions. E) They are reversible reactions.

C) hydrogen bond

21) What is the type of weak bond between the hydrogen of one molecule and the nitrogen of another molecule, where the two dont actively share an electron? A) ionic bond B) covalent bond C) hydrogen bond D) disulfide bond E) hydrophobic bond

B) covalent bond

22) What is the type of strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule? A) ionic bond B) covalent bond C) hydrogen bond

A) ionic bond

23) What is the type of bond between ions in salt? A) ionic bond B) covalent bond C) hydrogen bond

D) uracil

24) A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation? A) phosphate B) nitrogen C) guanine D) uracil E) thymine

D) nucleic acid

25) Structurally, ATP is most like which type of molecule? A) carbohydrate B) lipid C) protein D) nucleic acid

D) nucleic acids

26) What do genes consist of? A) carbohydrates B) lipids C) proteins D) nucleic acids

C) protein

27) Which molecule is composed of a chain of amino acids? A) carbohydrate B) lipid C) protein D) nucleic acid

B) lipids

28) Which are the primary molecules making up plasma membranes in cells? A) carbohydrates B) lipids C) proteins D) nucleic acids

C) eukaryotic plasma membranes.

29) The antimicrobial drug imidazole inhibits sterol synthesis. This would most likely interfere with A) bacterial cell walls. B) fungal cell walls. C) eukaryotic plasma membranes. D) prokaryotic plasma membranes. E) genes.

C) MgCl2

3) Antacids neutralize acid by the following reaction. Identify the salt in the following equation: Mg(OH)2 + 2HCl MgCl2 + H2O A) Mg(OH)2 B) HCl C) MgCl2 D) H2O E) None of the answers is correct.

Answer: TRUE

3) Individual covalent bonds are stronger than individual ionic bonds.

C) c

30) In Figure 2.1, which is an alcohol? A) a B) b C) c D) d E) e

D) d

31) Which compound in Figure 2.1 is an ester? A) a B) b C) c D) d E) e

A) a

32) Which compound in Figure 2.1 is an organic acid? A) a B) b C) c D) d E) e

A) L-isomers

33) Most amino acids found in cells demonstrate what type of chirality? A) L-isomers B) D-isomers C) C-isomers D) B-isomers E) A-isomers

E) peptide bond

34) Figure 2.3 What kind of bond is at the arrow in Figure 2.3? A) disulfide bridge B) double covalent bond C) hydrogen bond D) ionic bond E) peptide bond

D) The number of unsaturated chains must increase.

35) An E. coli culture that has been growing at 37C is moved to 25C. Which of the following changes must be made in its plasma membrane to help it cope with the decrease in temperature? A) The number of phosphate groups must increase. B) The viscosity must increase. C) The number of saturated chains must increase. D) The number of unsaturated chains must increase. E) No changes are necessary.

E) proteins.

36) Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 35S. After a 48-hour incubation, the 35S would most likely be found in the S. cerevisiaes A) carbohydrates. B) nucleic acids. C) water. D) lipids. E) proteins.

A) plasma membrane.

37) Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 32P. After a 48-hour incubation, the majority of the 32P would be found in the S. cerevisiaes A) plasma membrane. B) cell wall. C) water. D) proteins. E) carbohydrates.

B) glucose.

38) Starch, dextran, glycogen, and cellulose are polymers of A) amino acids. B) glucose. C) fatty acids. D) nucleic acids. E) acids.

C) NaOH Na+ + OH

39) Which of the following is a base? A) C2H5OCOOH H+ + C2H5OCOO B) C2H5OH C) NaOH Na+ + OH D) H2O H+ + OH E) H2CO

Answer: TRUE

4) All chemical reactions are, in theory, reversible.

B) Water molecules are formed by hydrolysis.

4) Which of the following statements is FALSE? A) Salts readily dissolve in water. B) Water molecules are formed by hydrolysis. C) Water freezes from the top down. D) Water is formed as a part of a dehydration synthesis reaction. E) Water is a polar molecule.

D) C12H22O11

40) Two glucose molecules are combined to make a maltose molecule. What is the chemical formula for maltose? A) C3H6O3 B) C6H12O6 C) C12H24O12 D) C12H22O11 E) C12H23O10

C) nonpolar

41) If an amino acid contained a hydrocarbon (a group of multiple carbons and hydrogens linked together) as its side group, in which of the following categories could it be appropriately designated? A) hydrophilic B) polar C) nonpolar D) basic E) acidic

Answer: TRUE

5) The formation of ADP from ATP can be defined as a hydrolytic reaction.

A) ionic bond

5) Which of the following is the type of bond holding K+ and I ions in KI? A) ionic bond B) covalent bond C) hydrogen bond

Answer: TRUE

6) The density of liquid water is greater than the density of ice.

C) hydrogen bond

6) Which of the following is the type of bond between molecules of water in a beaker of water? A) ionic bond B) covalent bond C) hydrogen bond

Answer: FALSE

7) A basic solution is expected to contain more hydrogen ions than hydroxyl ions.

B) covalent bond

7) What is the type of bond holding hydrogen and oxygen atoms together in a single H2O molecule? A) ionic bond B) covalent bond C) hydrogen bond

Answer: FALSE

8) All forms of life function optimally at a pH of 7.

A) dehydration synthesis reaction

8) Identify the following reaction: Glucose + Fructose → Sucrose + Water A) dehydration synthesis reaction B) hydrolysis reaction C) exchange reaction D) reversible reaction E) ionic reaction

B) hydrolysis reaction

9) Identify the following reaction: Lactose + H2O --> glucose + galactose A) dehydration synthesis reaction B) hydrolysis reaction C) exchange reaction D) reversible reaction E) ionic reaction

Answer: FALSE

9) There are some forms of life on Earth that can survive without water.

B) 46

Using the information in Table 2.1, calculate the molecular weight of ethanol, C2H5OH. A) 96 B) 46 C) 34 D) 33 E) The answer cannot be determined.