Mastering Microbiology CH2

Based on your knowledge of DNA and RNA structure, drag each item to the appropriate box to indicate whether it best describes DNA or RNA.

DNA the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and thymine (T)the pentose sugar is deoxyribose; it functions by determining the heredity of trait; it is double-stranded in cells and most DNA viruses RNA the nitrogen-containing bases are adenine (A), cytosine (C), guanine (G), and uracil (U)it is single-stranded in cells and most RNA viruses; the pentose sugar is ribose; it functions in protein synthesis

Which of the following is not a correct statement about ionic bonding? Ionic bonds produce compounds. Ions are formed first, and then their opposite electric charges draw the atoms close, forming the bond. Electrons are shared between the two atoms. Valence electrons are either gained or lost.

Electrons are shared between the two atoms.

Which molecule demonstrates the widest range of functions due to its ability to adopt multiple conformations? DNA RNA Both molecules carry out a wide range of activities within the cell.

RNA

Protein structure is directly related to the function of the protein. Which of the following is an accurate description of the level of structure in a protein? View Available Hint(s) Primary protein structure refers to the polypeptide chain folds that give a protein a unique shape. Tertiary protein structure is the overall three-dimensional shape involving interactions between various amino acids and their side groups. Secondary structure is the unique sequence of amino acids linked together. Quaternary protein structure is the localized, repetitive twisting or folding of the polypeptide chain.

Tertiary protein structure is the overall three-dimensional shape involving interactions between various amino acids and their side groups.

Protein structure is directly related to the function of the protein. Which of the following is an accurate description of the level of structure in a protein? View Available Hint(s) Tertiary protein structure is the overall three-dimensional shape involving interactions between various amino acids and their side groups. Primary protein structure refers to the polypeptide chain folds that give a protein a unique shape. Secondary structure is the unique sequence of amino acids linked together. Quaternary protein structure is the localized, repetitive twisting or folding of the polypeptide chain.

Tertiary protein structure is the overall three-dimensional shape involving interactions between various amino acids and their side groups.

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

Tertiary structures are formed only from covalent bonds.

How is ATP used in our bodies? ATP is used to make potential energy. It is converted to ADP for storage and later use. The energy released from ATP is converted into kinetic energy to do work. It is used to create more energy.

The energy released from ATP is converted into kinetic energy to do work

What type of reaction is represented by the equation below? Molecule AB →Molecule A + Molecule B View Available Hint(s) reversion reaction synthesis reaction exchange reaction decomposition reaction

decomposition reaction

Choose from the following the answer that best finishes this statement. View Available Hint(s) dehydration synthesis reaction that removes a hydroxyl group from the carboxyl end of the amino acid and reforms the bond with the nitrogen from the amino group that has lost a hydrogen atom dehydration reaction that removes a hydroxyl group from the amino end of the amino acid and reforms the bond with the nitrogen from the amino group that has lost a hydrogen atom reaction that removes a hydroxyl group from one of the amino acids and reforms the bond with the nitrogen from another amino acid that has lost a hydrogen atom dehydration reaction that removes water to allow for the formation of a bond between two amino acids

dehydration synthesis reaction that removes a hydroxyl group from the carboxyl end of the amino acid and reforms the bond with the nitrogen from the amino group that has lost a hydrogen atom

What is the term used to describe the unfolding of a protein? denaturation dehydration hydrolysis catalysis

denaturation

The energy stored in ATP comes from which of the following? heat adenosine triphosphate food molecules kinetic energy

food molecules

Which bond is best described as an intermolecular attraction due to partial charges formed in polar covalent bonds? View Available Hint(s) hydrophobic bonds hydrogen bond ionic bonds covalent bonds

hydrogen bond

Which of the following is the type of bond between molecules of water in a beaker of water? ionic bond covalent bond hydrogen bond

hydrogen bond

Which type of bond is found between Na+ and Cl- ions in NaCl? View Available Hint(s) double bond covalent bond hydrogen bond ionic bond

ionic bond

Which of the following lipids is an important component of the outer membrane of certain bacteria called Gram-negative bacteria? ergosterol cholesterol lipopolysaccharide triglyceride

lipopolysaccharide

What would be the function of the lipid shown? source of stored energy transmission of information maintenance of membrane fluidity catalyst that speeds up chemical reactions

maintenance of membrane fluidity

What type of carbohydrate is pictured? View Available Hint(s) complex carbohydrate monosaccharide polysaccharide disaccharide

monosaccharide

What do genes consist of? carbohydrates lipids proteins nucleic acids

nucleic acids

Gastric juices have a pH of 1 or 2. This would indicate which of the following? View Available Hint(s) numerous H+ ions and a low pH numerous OH- ions and a high pH neutral fluids, perfect for decomposition reactions numerous OH- ions and a low pH

numerous H+ ions and a low pH

Gastric juices have a pH of 1 or 2. This would indicate which of the following? View Available Hint(s) neutral fluids, perfect for decomposition reactions numerous OH- ions and a high pH numerous OH- ions and a low pH numerous H+ ions and a low pH

numerous OH- ions and a low pH

Which level is most important in determining the structure and function of a protein? primary secondary tertiary quaternary

primary

Identify the following reaction: NH4OH ↔ NH3 + H2O dehydration synthesis reaction hydrolysis reaction exchange reaction reversible reaction ionic reaction

reversible reaction

Which level of protein structure is characterized by twists and turns stabilized by hydrogen bonds? primary secondary tertiary quaternary

secondary

Which of the following describes inorganic molecules? View Available Hint(s) large and typically complex molecules with carbon and hydrogen bonds molecules including nucleic acids, lipids, proteins, and carbohydrates small and structurally simple compounds, which typically lack carbon and in which ionic bonds may play an important role molecules mainly held together by covalent bonds

small and structurally simple compounds, which typically lack carbon and in which ionic bonds may play an important role

Which of the following describes inorganic molecules? View Available Hint(s) molecules mainly held together by covalent bonds molecules including nucleic acids, lipids, proteins, and carbohydrates small and structurally simple compounds, which typically lack carbon and in which ionic bonds may play an important role large and typically complex molecules with carbon and hydrogen bonds

small and structurally simple compounds, which typically lack carbon and in which ionic bonds may play an important role

There is a scheme of a lipid molecule, a base of which is formed by 3 hexane and 1 pentane rings. What type of lipid is pictured? sterol phospholipid fat triglyceride

sterol

A covalent bond results from __________. View Available Hint(s) the complete transfer of electrons from one atom to another the attraction of polar molecules to one another the sharing of electrons between two atoms the sharing of protons between two atoms

the sharing of electrons between two atoms

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. four one two three

two

Which of the following is true of ATP? View Available Hint(s) ATP is a nucleic acid. ATP is the principal energy-storing molecule in the cell. ATP represents an unlimited energy supply for cells. ATP stores energy in phosphate bonds.

ATP stores energy in phosphate bonds.

Choose the statement that does NOT pertain to amino acids. View Available Hint(s) Amino acids always contain a sulfur atom in their R-side group. The R-side group will determine the overall chemical properties of an individual amino acid. All amino acids must contain a nitrogen-based molecule and a carboxylic acid. The groups composing an amino acid are located around a central alpha-carbon.

Amino acids always contain a sulfur atom in their R-side group.

Based on the rules of complementary base pairing, the amount of guanine in a molecule of DNA will always be equal to the amount of cytosine. The same rule applies to adenine and thymine. What would be the sequence of the complementary DNA strand 5'ATCGGCTACG3'? 3'TAGCCGATGC'5 3'GAGCCTAGCA'5 5'GCCTAGCGAT'3 5'TAGCCGATGC'3

3'TAGCCGATGC'5

The two strands in a DNA helix are described as being antiparallel, or in opposite orientations. If one DNA strand is in the 5' to 3' orientation, the complementary DNA strand is orientated in which direction? View Available Hint(s) 1' to 5' 3' to 1' 3' to 5' 5' to 3' 5' to 1'

3' to 5'

What is the difference between a ketone and an aldehyde? A ketone contains nitrogen; an aldehyde does not. A ketone has a C=O at its terminal end; an aldehyde does not. A ketone contains an -OH attached to its C=O; an aldehyde does not. A ketone has an internal C=O flanked by carbons; an aldehyde does not.

A ketone has an internal C=O flanked by carbons; an aldehyde does not.

Which of the following formulas represents a triglyceride? C10H16N5O13P3 C6H12O6 C55H98O6 C3H7NO2

C55H98O6

Which of the following formulas represents a carbohydrate? C3H7NO2 C8H16O8 C10H16N5O13P3 C55H98O6

C8H16O8

Which of the following statements is true regarding organic molecules? View Available Hint(s) Proteins are composed of subunits called fatty acids and glycerol made up of carbon, hydrogen, and oxygen. Carbohydrates are a large and diverse group of molecules composed of carbon, hydrogen, and oxygen. Examples include glycogen and starch. Triglycerides are nonpolar molecules composed of peptide bonds linking amino acids. Nucleic acids are composed of proteins.

Carbohydrates are a large and diverse group of molecules composed of carbon, hydrogen, and oxygen. Examples include glycogen and starch.

Which of the following statements is true regarding organic molecules? View Available Hint(s) Proteins are composed of subunits called fatty acids and glycerol made up of carbon, hydrogen, and oxygen. Triglycerides are nonpolar molecules composed of peptide bonds linking amino acids. Nucleic acids are composed of proteins. Carbohydrates are a large and diverse group of molecules composed of carbon, hydrogen, and oxygen. Examples include glycogen and starch.

Carbohydrates are a large and diverse group of molecules composed of carbon, hydrogen, and oxygen. Examples include glycogen and starch.

Which of the following is a major function of carbohydrates? View Available Hint(s) Carbohydrates store information for the cell. Carbohydrates regulate blood sugar levels. Carbohydrates serve as catalysts for the cell. Carbohydrates are the primary source of energy for the cell.

Carbohydrates are the primary source of energy for the cell.

Two components are common to all four DNA nucleotides, and one component differs. Drag each of the following terms to the appropriate column to indicate whether that item is commonly found in all DNA nucleotides or only in specific DNA nucleotides.

Found in all DNA nucleotides deoxyribose sugar; phosphate Found only in specific DNA nucleotides cytosine; thymine; adenine; guanine

Place the chemical formulae into the correct bins. There will only be one formula per bin.

Hydroxyl -OH Phosphate -PO42- Amino -NH2 Carboxyl -COOH Sulfhydryl -SH

Place the chemical formulae into the correct bins. There will only be one formula per bin.

Phosphate (−PO42−) is involved in energy transfers Amino (−NH2) acts as a base and is often positively charged Carboxyl (−COOH) acts as an acid and is often negatively charged Sulfhydryl (−SH) participates in strong covalent bonds that stabilize folded proteins

Sort the following molecules based on whether they are polar or non-polar.

Polar covalent H-N;O-H Non-polar covalent O=O;H-H;C-H

Which of the following is not a true statement about covalent bonding? It occurs when atoms share valence electrons to become stable. Polar covalent bonds produce molecules with slight electrical charges. It forms strong chemical bonds. In nonpolar covalent bonds, electrons are shared unequally.

In nonpolar covalent bonds, electrons are shared unequally.

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

It has 12 neutrons in its nucleus.

Which of the following best characterizes a hydrogen bond? It forms only between nonpolar molecules. It is a weak and temporary electrical attraction between two polar molecules. It is a strong chemical bond formed by the sharing of valence electrons. It is formed only between different molecules (intermolecular).

It is a weak and temporary electrical attraction between two polar molecules.

Which of the following would have the greatest impact on blood glucose? View Available Hint(s) Apple (GI value =36) Jelly beans (GI value = 78) Wheat tortilla (GI value = 30) Soy beans (GI value =15)

Jelly beans (GI value = 78)

Which of the following pairs is mismatched? NaOH ↔ Na+ + OH- base H2SO4 ↔ 2H+ + SO42- acid KH2PO4 ↔ K+ + H2PO4- acid MgSO4 ↔ Mg2+ + SO42- salt HF ↔ H+ + F- - acid

KH2PO4 ↔ K+ + H2PO4- acid

What is the difference between these two molecules? There are 2 molecules. Molecule 1 is H3CCH3. Molecule 2 is H2COHCH3. The molecule on the left is polar and hydrophilic; the molecule on the right is non-polar and hydrophobic. The molecule on the left is non-polar and hydrophobic; the molecule on the right is polar and hydrophilic. There are no differences; they both have two carbons. The molecule on the left is non-polar and hydrophilic; the molecule on the right is polar and hydrophobic.

The molecule on the left is non-polar and hydrophobic; the molecule on the right is polar and hydrophilic.

Which of the following comparisons between sugar and sugar substitutes is incorrect? View Available Hint(s) They are structurally identical. Sugar is not as sweet as sugar substitutes. They are both considered organic molecules. Sugar has a high glycemic index value compared to sugar substitutes.

They are structurally identical.

Complete the following statements by dragging the correct term to the appropriate box.

Thymine Adenine forms base pairs with _____. Guanine Cytosine forms base pairs with _____. Cytosine Guanine forms base pairs with _____. Adenine Thymine forms base pairs with _____.

With which nucleotide does adenine base-pair in a folded RNA molecule? U G T A

U

Choose from the following statements the one that best describes the reactions illustrated in the figure above. View Available Hint(s) Using energy, an enzyme removes a hydroxyl group from the carboxyl group of one amino acid and a hydrogen atom from the amino group of another amino acid to join the amino acids in a dehydration reaction that releases water. Alternatively, another enzyme breaks the peptide bond and uses a water molecule to join a hydrogen atom to the carboxyl group of one amino acid and a hydroxyl group to the amino group of another amino acid in a hydration reaction. Using energy, an enzyme removes a hydroxyl group from the carboxyl group of one amino acid and a hydrogen atom from the amino group of another amino acid to join the amino acids in a dehydration synthesis reaction that releases water. Alternatively, another enzyme breaks the peptide bond and uses a water molecule to join a hydroxyl group to the carboxyl group of one amino acid and a hydrogen atom to the amino group of another amino acid in a hydrolysis reaction. Using energy, an enzyme removes a hydroxyl group from the amino group of one amino acid and a hydrogen atom from the carboxyl group of another amino acid to join the amino acids in a dehydration reaction that releases water. Alternatively, another enzyme breaks the peptide bond and uses a water molecule to join a hydroxyl group to the carboxyl group of one amino acid and a hydrogen atom to the amino group of another amino acid in a hydration reaction. Using energy, an enzyme removes a hydroxyl group from the carboxyl group of one amino acid and a hydrogen atom from the amino group of another amino acid to join the amino acids in a hydration reaction that releases water. Alternatively, another enzyme breaks the peptide bond and uses a water molecule to join a hydroxyl group to the carboxyl group of one amino acid and a hydrogen atom to the amino group of another amino acid in a dehydration reaction.

Using energy, an enzyme removes a hydroxyl group from the carboxyl group of one amino acid and a hydrogen atom from the amino group of another amino acid to join the amino acids in a dehydration synthesis reaction that releases water. Alternatively, another enzyme breaks the peptide bond and uses a water molecule to join a hydroxyl group to the carboxyl group of one amino acid and a hydrogen atom to the amino group of another amino acid in a hydrolysis reaction.

Which of the following would not be considered an organic compound? View Available Hint(s) Methane (CH4) Water (H2O) Glucose (C6H12O6) Saccharin (C6H4SO2CON)

Water (H2O)

Which of the following is true of nonpolar molecules? Water molecules are not nonpolar. They are larger than polar molecules. They include the electrolytes. They are formed by unequal sharing of electrons.

Water molecules are not nonpolar.

Which of the following statements about water is true? View Available Hint(s) Water is an organic molecule. Water is not a good temperature buffer, because there is no hydrogen bonding between water molecules. Water plays an important role in dehydration synthesis. Water is typically a nonpolar solvent.

Water plays an important role in dehydration synthesis.

Which compound in the figure is an organic acid? a b c d e

a

Which of the following correctly describes the structure of an atom? View Available Hint(s) a nucleus with negatively charged protons, uncharged neutrons, and orbiting positively charged electrons a nucleus with positively charged protons, uncharged neutrons, and orbiting negatively charged electrons a nucleus that contains protons, neutrons, and electrons, which are all charged but balance one another a nucleus with negatively charged electrons balanced by positively charged protons and orbiting uncharged neutrons

a nucleus with positively charged protons, uncharged neutrons, and orbiting negatively charged electrons

In a water molecule, the oxygen atom contains __________ charge, and the hydrogen exhibits __________ charge. View Available Hint(s) a partially positive; a partially negative a partially negative; a partially positive a partially positive; a partially positive a partially negative; no

a partially negative; a partially positive

When bonds between atoms are graphically depicted, a solid line represents covalent bonds, and a dotted line represents hydrogen bonds. Based on this figure, hydrogen bonds are located between which components of DNA nucleotides? View Available Hint(s) between a nitrogen-containing base and deoxyribose sugar between a deoxyribose sugar and phosphate group between a nitrogen-containing base and phosphate group between two deoxyribose sugars between two nitrogen-containing bases

between two nitrogen-containing bases

Which type of molecule is composed of (CH2O) units? protein carbohydrate lipid nucleic acid

carbohydrate

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

covalent bond

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

covalent bond

Which compound in the figure is an ester? a b c d e

d