Chapter 8: Microbial Biology

Question 1

Biochemistry

Answer 1

The discipline that studies the chemistry of life, and its objective is to explain form and function based on chemical principles.

Question 2

Organic Chemistry

Answer 2

The discipline devoted to the study of carbon-based chemistry, which is the foundation for the study of biomolecules and the discipline of biochemistry.

Question 3

Macronutrients

Answer 3

Hydrogen, carbon, oxygen, nitrogen, phosphorus, and sulfur; they account for about 99% of the dry weight of cells.

Question 4

Micronutrients/ Trace Elements

Answer 4

Elements required by some cells in very small amounts like sodium, potassium, magnesium, zinc, iron, calcium, molybdenum, copper, cobalt, manganese, or vanadium.

Question 5

Inorganic Compounds

Answer 5

Compounds that do not contain carbon.

Question 6

Organic Molecules

Answer 6

Typically organized around chains of carbon atoms.

Question 7

Biomolecules

Answer 7

A molecule that is produced by a living organism.

Question 8

Carbon Skeleton

Answer 8

Carbon atoms binding together in large numbers.

Question 9

Macromolecule

Answer 9

A molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer.

Question 10

Monomer

Answer 10

A molecule that can be bonded to other identical molecules to form a polymer.

Question 11

Polymer

Answer 11

A substance that has a molecular structure consisting chiefly or entirely of a large number of similar units bonded together.

Question 12

Dehydration Synthesis

Answer 12

Monomer molecules bind end to end in a process that results in the formation of water molecules as a byproduct.

Question 13

Starch

Answer 13

Branched polymer, the primary energy storage molecule in plants.

Question 14

Glycogen

Answer 14

Branched polymer; the primary energy-storage molecule in animals and bacteria.

Question 15

Cellulose

Answer 15

Consists of a linear chain of glucose molecules and is a common structural component of cell walls in plants and other organisms.

Question 16

Glycosidic Bonds

Answer 16

How the monomeric units of polysaccharides are linked together.

Question 17

Polysaccharides (Glycans)

Answer 17

Large polymers composed of hundreds of monosaccharide monomers, they are not sweet and, in general, they are not soluble in water.

Question 18

Ergosterol

Answer 18

Produced by fungi, and some protozoa, which strengthens the cell membranes of these organisms.

Question 19

Hopanoids

Answer 19

Produced by bacteria, are multi-ringed structures that strengthen bacterial membranes.

Question 20

Cholesterol

Answer 20

Consists of four rings with a double bond in one of the rings, and a hydroxyl group at the sterol-defining position, its function is to strengthen cell membranes in eukaryotes and in bacteria without cell walls.

Question 21

Aresteols

Answer 21

The most common type of steroid containing an OH group, mainly hydrophobic molecules, but also have hydrophilic hydroxl groups.

Question 22

Steroids

Answer 22

A complex, ringed structures that are found in cell membranes, some function as horomones.

Question 23

Isoprenoids/Terpenoids

Answer 23

Branched lipids, formed by chemical modifications of the isoprene molecule.

Question 24

Lipid-Bilayer/ Unit Membranes

Answer 24

Large, two-dimensional assemblies of phospholipids congregated tail to tail.

Question 25

Micelles

Answer 25

Spherical assemblies containing a hydrophobic interior of phospholipids tails and an outer surface of polar head groups.

Question 26

Amphipathic

Answer 26

A molecule presenting a hydrophobic portion and a hydrophobic moiety.

Question 27

Triacylglycerol/Triglyceride

Answer 27

Formed when three fatty acids are chemically linked to a glycerol molecule, the primary components of adipose tissue, and are major components of sebum.

Question 28

Unsaturated Fatty Acids

Answer 28

Fatty acids with hydrogen chains containing at least one double bond which causes kinks in their carbon skeleton.

Question 29

Saturated Fatty Acids

Answer 29

Fatty acids with hydrocarbon chains that contain only single bonds, they have the greatest number of hydrogen atoms possible and are, therefore, “saturated” with hydrogen.

Question 30

Fatty Acids

Answer 30

Lipids that contain long-chain hydrocarbons terminated with a carboxylic acid functional group.

Question 31

Lipoprotein

Answer 31

A conjugate protein that has a lipid attached.

Question 32

Glycoprotein

Answer 32

A conjugated protein that has a carbohydrate attached.

Question 33

Conjugated Proteins

Answer 33

Have a nonprotein portion.

Question 34

Quaternary Structure

Answer 34

Stabilized by relatively weak interactions.

Question 35

Polypeptides/Protein Subunits

Answer 35

These proteins function adequately only when all subunits are present and appropriately configured.

Question 36

Denatured

Answer 36

Implies the loss of the secondary structure and tertiary structure (and, if present, the quaternary structure) without the loss of the primary structure.

Question 37

Native Structure

Answer 37

Folded proteins that are fully functional in their normal biological roles.

Question 38

Disulfide Bridges

Answer 38

Bonds between the sulfhydrl (-SH) functional groups on amino acid side groups; hydrogen bonds; ionic bonds; and hydrophobic interactions between nonpolar side chains.

Question 39

Tertiary Structure

Answer 39

The large-scale three-dimensional shape of a single polypeptide chain, determined by interactions between amino acids residues that are far apart in the chain.

Question 40

Beta-Plated Sheet

Answer 40

The pleats are formed by similar hydrogen bonds between continuous sequences of carbonyl and amino groups that are further separated on the backbone of the polypeptide chain.

Question 41

Alpha-Helix

Answer 41

The helix is held by hydrogen bonds between the oxygen atom in a carbonyl group of one amino acid and the hydrogen atom of the amino group that is just four amino acid units farther along the chain.

Question 42

Secondary Structure

Answer 42

When hydrogen bonding occurs between amine and carbonly functional groups within the peptide backbone, resulting in localized folding of the polypeptide chain into helices and sheets.

Question 43

Primary Structure

Answer 43

The sequence of amino acids that make up the polypeptide chain.

Question 44

MALDI-TOF

Answer 44

Identifies microorganisms by determining the specimen’s mass spectrum and then comparing it to a database that contains known mass spectra for thousands of microorganisms.

Question 45

FAME Analysis

Answer 45

Fatty acids are extracted from the membranes of microorganisms, chemically altered to form volatile methyl esters, and analyzed by gas chromatography.

Question 46

PLFA Analysis

Answer 46

Phospholipids that have released their fatty acids are subjected to FAME analysis.