Microbiology Midterm

1. FAME analysis involves which of the following? A. gas chromatography B. high-pressure liquid chromatography C. immunological testing D. mass spectrometry

A

1. The phospholipid molecules in the plasma membrane are which of the following? A. amphipathic B. hydrophilic only C. hydrophobic only D. in the shape of micelles

A

1. Which are the components found in starch? A. amylose and amylopectin B. amylose and glycogen C. cellulose and glycogen D. glucosamine and muramic acid

A

Monomer

A simple compound whose molecules can join together to form polymers

exergonic reaction

A spontaneous chemical reaction in which there is a net release of energy.

Match each type of microbe with the best example. A. aerotolerant B. facultative anaerobe C. microaerophile D. obligate anaerobe i. Streptococcus ii. Clostridium difficile iii. Campylobacter pylori iv. Staphylococcus

A. i., B. iv., C. iii., D. ii

What is the energy currency of the cell?

Adenosine triphosphate (ATP)

metabolism

All of the chemical reactions that occur within an organism

1. How many single covalent bonds can oxygen form? A. one B. two C. three D. four

B

1. The phospholipids of the plasma membrane contain which subcomponents? A. a wax, a glycerol, and a phosphate group B. two fatty acids, a glycerol, and a phosphate group C. three fatty acids, a glycerol, and a phosphate group D. four sphingolipids and a phosphate group

B

1. Which type of molecule is CH3(CH2)14COOH? A. amino acid B. fatty acid C. monosaccharide D. nucleotide

B

Which group comprises all lithotrophs? A. algae B. autotrophs C. microbes D. plants

C

Which of the following processes produces hydrogen sulfide? A. anoxygenic photosynthesis B. oxygenic photosynthesis C. anaerobic respiration D. chemoautrophy

C

Which type of microbes thrive in the Great Salt Lake? A. barophilic B. barotolerant C. extreme halophiles D. halotolerant

C

carboxylic acid

COOH

The light-independent reactions of photosynthesis are also known as the ________.

Calvin-Benson cycle (the names Calvin cycle or dark reactions may also be used, although the latter is not a preferred name)

What are inorganic ions that stabilize enzyme conformation and function?

Cofactors

________ is a hormone produced in response to stress; it is marketed in a synthetic form as hydrocortisone to reduce skin irritation and inflammation.

Cortisol

1. Amylose is a component of which of the following? A. cellulose B. disaccharides C. nucleotides D. starch

D

Which method involves the analysis of membrane-bound carbohydrates? A. FAME B. PLFA C. MALDI-TOF D. Lancefield group testing

D

Most commonly, glycolysis occurs by the ________ pathway.

Embden-Meyerhof

Disulfide bridges are a major component of the secondary structure of a protein.

False

Oxygen is necessary for an electron transport chain to function.

False

Quorum sensing always occurs between members of the same species.

False

occurs when the product of a metabolic pathway noncompetitively binds to an enzyme early on in the pathway, ultimately preventing the synthesis of the product

Feedback inhibition

1. ________ is an important accessory pigment used by brown algae to aid photosynthesis at low light levels.

Fucoxanthin

________ results in the production of a mixture of fermentation products, including lactic acid, ethanol and/or acetic acid, and CO2.

Heterolactic fermentation

Provide a basic overview of the major steps of the sulfur cycle.

Hydrogen sulfide is oxidized to elemental sulfur and then to sulfate.

Cyclic photophosphorylation uses only photosystem ________.

I [PSI or P700]

Ester

Lipids nucleic acid

matrix assisted laser desorption/ionization time of flight mass spectrometry - what is the acronym?

MALDI-TOF

________ are bacteria and archaea that use methane as a carbon source.

Methanotrophs

Does glycolysis require oxygen?

No, it is anaerobic

Transition Reaction

Pyruvate is converted to acetyl coenzyme A links glycolysis to aerobic respiration

________ is a type of medium used to detect the production of an extracellular protease called caseinase.

Skim milk agar

nucleic acids functions

Storage and transfer of genetic information

substrate-level phosphorylation

The formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.

1. What is the difference between the optimum oxygen concentration and the maximum permissive oxygen concentration?

The optimum oxygen concentration is the concentration at which a microbe grows best. In contrast, the maximum permissive oxygen concentration is the maximum concentration at which a microbe can grow.

active site

The part of an enzyme or antibody where the chemical reaction occurs.

proton motive force

The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across biological membranes during chemiosmosis.

Phosphorylation

The transfer of a phosphate group, usually from ATP, to a molecule. Nearly all cellular work depends on ATP energizing other molecules by phosphorylation.

Indicate the α carbon on the amino acid below.

The α carbon is the carbon to which the amino group, carboxyl group, hydrogen, and R group are joined.

Generation time in prokaryotes refers to the amount of time required for the doubling of the population through a single round of binary fission.

True

Autotrophs

convert inorganic carbon dioxide into organic carbon

primordial soup hypothesis

energy from sunlight and lightning allowed the first organic molecules to form

glycogen

energy storage polymer found in animal cells and bacteria

acetone-butanol-ethanol fermentation is used in the production of _______________.

industrial solvents

electron transport chain of cellular respiration - where?

inner mitochondrial membrane

Cofactors

inorganic ions such as iron (Fe2+) and magnesium (Mg2+) that help stabilize enzyme conformation and function.

1. The generation time for a particular bacterial species in a particular batch culture is called the ________.

intrinsic growth rate

feedback inhibition (negative feedback)

involves the use of a pathway product to regulate its own further production. The cell responds to the abundance of specific products by slowing production during anabolic or catabolic reactions

secondary protein structure

local folding of the polypeptide chain into helices or sheets

competitive inhibitor

molecule similar enough to a substrate that it can compete with the substrate for binding to the active site by simply blocking the substrate from binding.

What is the process called when a phosphate group is added to a molecule?

phosphorylation

purple sulfur bacteria

photoautotroph

green nonsulfur bacteria

photoheterotroph

Competitive inhibitors

regulate enzymes by binding to an enzyme's active site, preventing substrate binding

In oxygenic photosynthesis, oxygen is released because ________is split to provide an electron to replace one that absorbs a photon of light .

water

What are the products of the Krebs cycle?

2 CO2 1 ATP 3 NADH 1 FADH2

Glycolysis cannot occur in an anaerobic environment.

False

1. ________is when the cell membrane moves away from the cell wall due to osmosis occurring within the cytoplasm.

Plasmolysis

The sequence of amino acids in a protein is called its __________.

Primary structure

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

Which of the following best describes catabolic pathways?

They break down large molecules into smaller components.

redox reactions

When there is a transfer of one or more electrons from one reactant to another.

Do prokaryotic organisms typically depend on organic molecules for metabolism?

Widely variable

carbonyl

ketones aldehydes carboxylic acids amides

aerobic respiration - how it works?

uses an electron transport chain with O2 as the terminal electron acceptor

anaerobic respiration - how it works?

uses an electron transport chain with an inorganic molecule such as SO42- as the terminal electron acceptor

chemoautotroph

uses chemical energy and an inorganic carbon source

chemoheterotroph

uses chemical energy and an organic carbon source

photoautotroph

uses light energy and an inorganic carbon source

Structural diagrams for the linear and cyclic forms of a monosaccharide are shown. (a) What is the molecular formula for this monosaccharide? (Count the C, H and O atoms in each to confirm that these two molecules have the same formula, and report this formula.) (b) Identify which hydroxyl group in the linear structure undergoes the ring-forming reaction with the carbonyl group.

(a) The linear structure shows five carbon atoms, 10 hydrogen atoms, and five oxygen atoms, so its molecular formula is C5H10O5. The same is true for the ring structure. (b) To form the five-member ring, the hydroxyl group circled in the following structure must be involved in the reaction:

The structural formula shown corresponds to penicillin G, a narrow-spectrum antibiotic that is given intravenously or intramuscularly as a treatment for several bacterial diseases. The antibiotic is produced by fungi of the genus Penicillium. (a) Identify three major functional groups in this molecule that each comprise two simpler functional groups. (b) Name the two simpler functional groups composing each of the major functional groups identified in (a).

(a) The structure contains two amide groups and one carboxylic acid group. (b) The amide groups are composed of carbonyl (C=O) and amine (R3N) functional groups. The carboxylic acid group is composed of carbonyl (C=O) and hydroxyl (OH) groups.

1. Which of the following molecules is an organic molecule? A. CO2 B. CaCO3 C. CH3OH D. H2O

C

propionic acid fermentation is used in the production of _______________.

Swiss cheese

Clostridium acetobutylicum - fermentation type?

acetone-butanol-ethanol

Ketone

carbohydrates

Streptococcus, Lactobacillus - fermentation type?

lactic acid

How is ATP made by ATP synthase?

oxidative phosphorylation

The figure depicts the structural formulas of glucose, galactose, and fructose. (a) Circle the functional groups that classify the sugars either an aldose or a ketose, and identify each sugar as one or the other. (b) The chemical formula of these compounds is the same, although the structural formula is different. What are such compounds called?

(a) All sugars contain hydroxyl functional groups. Glucose and galactose both contain aldehyde functional groups and are classified as aldoses. Fructose contains a ketone group and is classified as a ketose. (b) Structural isomers.

The image shown represents a tetrapeptide (a) How many peptide bonds are in this molecule? (b) Identify the side groups of the four amino acids composing this peptide.

(a) three peptide bonds (b) Left-to-right, the side groups are:

Match the fermentation pathway with the correct commercial product it is used to produce: 1.___ acetone-butanol-ethanol fermentation 2.___ alcohol fermentation 3.___ lactic acid fermentation 4.___ mixed acid fermentation 5.___ propionic acid fermentation A. bread B. pharmaceuticals C. Swiss cheese D. yogurt E. industrial solvents

1 E, 2 A, 3 D, 4 B, 5 C

What's the range of ATP made during anaerobic respiration?

1- 32 ATP

Match each polysaccharide with its description. 1. energy storage polymer in plants 2. structural polymer found in plants 3. structural polymer found in cell walls of fungi and exoskeletons of some animals 4. energy storage polymer found in animal cells and bacteria A. chitin B. glycogen C. starch D. cellulose

1. C; 2. D; 3. A; 4. B

How many turns of the Krbs cycle are required to process all of the carbon form one glucose molecule?

2

In glycolysis, what is the net gain from the breakdown of a glucose molecule?

2 ATP 2 NADH 2 pyruvate

Krebs Cycle Carbon Flow Molecules of Reduced Coenzymes Net ATP by substrate level phosphorylation Net ATP by oxidative phosphorylation Max ATP

2 acetyl -> 4 CO2 6 NADH + 2 FADH2 2 ATP 18 ATP from 6 NADH, 4 ATP from 2 FADH2 24 ATP

Transition Reaction Carbon Flow Molecules of Reduced Coenzymes Net ATP by substrate level phosphorylation Net ATP by oxidative phosphorylation Max ATP

2 pyruvate -> 2 acetyl + 2 CO2 2 NADH - 6 ATP from 2 NADH 6 ATP

quaternary protein structure

2+ protein chains forming functional protein produced by joining more than one polypeptide chain by interactions including hydrogen bonding, hydrophobic interactions, disulfide bonds, and ionic interactions

Per turn of the Krebs cycle, one acetyl is oxidized, forming ____ CO2, ____ ATP, ____ NADH, and ____ FADH2 molecules.

2; 1; 3; 1

For each turn of the Krebs Cycle, what is produced?

3 NADH 1 FADH2 1 ATP 2 CO2

What's the maximum amount of ATP made during aerobic respiration and oxidative phosphorylation?

34 ATP

tertiary protein structure

3D folding pattern of a protein due to side chain interactions

tertiary protein structure

3D folding pattern of a protein due to side chain interactions created from interactions between relatively distant amino acids, including hydrogen bonding, hydrophobic interactions, disulfide bonds, and ionic interactions

1. Which enantiomers rotate plane polarized light in a clockwise direction? A. + or d B. + or l C. - or d D. - or l

A

1. Which is a common type of secondary structure of proteins? A. the α helix B. the β helix C. the Δ helix D. the ω helix

A

1. Which of the following best describes the molecule lactose? A. disaccharide B. monosaccharide C. polysaccharide D. trisaccharide

A

1. Which of the following is not true of triglycerides? A. They are a type of phospholipid. B. They are considered simple lipids. C. They are hydrophobic. D. They contain glycerol and three fatty acids.

A

1. Which of the following refers to the term metabolism? A. all the reactions in a cell or organism B. all the reactions in a cell that break down molecules only C. all the reactions in a cell that build new molecules only D. all the reactions in a cell that decompose molecules only

A

1. Which of the following types of bonds joins monosaccharides together to form a polysaccharide? A. glycosidic bonds B. hydrogen bonds C. peptide bonds D. phosphodiester bonds

A

1. Why does it matter which enantiomer of a molecule is used for a medication? A. Enantiomers can have different pharmacologic effects and only one may be effective. B. It is usually easier to prepare one enantiomer than mixtures of both. C. The d form is typically more effective than the l form. D. The l form is typically more effective than the d form.

A

A candle jar is often used to grow which type of bacteria? A. capnophiles B. microaerophiles C. obligate aerobes D. obligate anaerobes

A

Bacteria most commonly reproduce using which of the following methods? A. binary fission B. budding C. meiosis D. mitosis

A

Capnophiles are bacteria that grow best under which of the following conditions? A. relatively high CO2 and relatively low oxygen concentrations B. relatively high oxygen and relatively low CO2 concentrations C. relatively low CO2 and oxygen concentrations D. relatively low oxygen and CO2 concentrations

A

Fatty acids are often degraded using which set of reactions? A. β-oxidation B. glycolysis C. photophosphorylation D. the tricarboxylic acid cycle

A

Glycolysis produces a net gain of which of the following? A. two ATP, two NADH, and two pyruvates B. two ATP, two NADH, and four pyruvates C. two ATP, four NADH, and two pyruvates D. four ATP, two NADH, and two pyruvates

A

Human pathogens are generally which type of microbe? A. mesophiles B. psychrophiles C. psychrotrophs D. thermophiles

A

If you grow two species of bacteria on mannitol salt agar to determine which can ferment mannitol, and you know both species can grow on the medium, which type of medium is the agar? A. differential B. selective C. both a differential medium and a selective medium D. neither a differential medium nor a selective medium

A

In prokaryotes, in which direction are hydrogen ions pumped by the electron transport system of photosynthetic membranes? A. to the outside of the plasma membrane B. to the inside (cytoplasm) of the cell C. to the stroma D. to the intermembrane space of the chloroplast

A

In prokaryotes, which of the following is true? A. As electrons are transferred through an ETS, H+ is pumped out of the cell. B. As electrons are transferred through an ETS, H+ is pumped into the cell. C. As protons are transferred through an ETS, electrons are pumped out of the cell. D. As protons are transferred through an ETS, electrons are pumped into the cell.

A

The building blocks of polymers are called which of the following? A. monomers B. macromolecules C. nucleic acids D. inorganic molecules

A

Triglycerides are broken down by which of the following? A. lipases B. nitrogenases C. phospholipases D. proteases

A

Which best describes bacterial growth during the log phase of the growth curve? A. exponential B. linear C. S-shaped D. stationary

A

Which method involves conversion of a microbe's lipids to volatile compounds for analysis by gas chromatography? A. FAME B. proteomic analysis C. MALDI-TOF D. Lancefield group testing

A

Which molecule is often called the cell's energy currency? A. adenosine triphosphate B. flavin adenine dinucleotide C. nicotinamide adenine dinucleotide D. nicotinamide adenine dinucleotide phosphate

A

Which of the following are inorganic molecules that bind to enzymes? A. cofactors B. holoenzymes C. apoenzymes D. coenzymes

A

Which of the following best describes a transition reaction? A. a reaction that converts pyruvate to acetyl CoA with the release of carbon dioxide B. a series of reactions that convert citric acid to oxaloacetate C. an optional reaction that transports pyruvate into the mitochondrion D. the reaction that converts glucose to glucose-6-phosphate in glycolysis

A

Which of the following best describes an endergonic reaction? A. absorbs energy from the environment B. is coupled with another reaction C. is involved in biosynthesis D. releases energy into the environment

A

Which of the following best describes catabolic pathways? A. They break down large molecules into smaller components. B. They must be coupled with the breakdown of ATP. C. They build up large molecules from smaller components. D. They always absorb energy.

A

Which of the following best describes how a microaerophile would grow in a thioglycolate tube culture? A. a short distance below the top of the medium, but not at the top B. at the bottom of the medium only, with no growth in the middle or top C. near and at the top of the medium, with no growth at the bottom D. throughout the medium

A

Which of the following best describes the difference between steroids and sterols? A. Sterols are a type of steroid with an OH group. b. Steroids contain rings, whereas sterols do not. C. Steroids are the most common type of sterol. D. Sterols are present in prokaryotes and steroids are not.

A

Which of the following best describes the subcomponents of pyrophosphate? A. two inorganic phosphate molecules B. two organic phosphate molecules C. three inorganic phosphate molecules D. three organic phosphate molecules

A

Which of the following bonds are not involved in tertiary structure? A. peptide bonds B. ionic bonds C. hydrophobic interactions D. hydrogen bonds

A

Which of the following is an inhibitor that binds to the active site of an enzyme? A. a competitive inhibitor B. a noncompetitive inhibitor C. an allosteric inhibitor D. an uncompetitive inhibitor

A

Which of the following is an organism that obtains its energy from the transfer of electrons originating from chemical compounds and its carbon from an inorganic source? A. chemoautotroph B. chemoheterotroph C. photoheterotroph D. photoautotroph

A

Which of the following is another term for generation time? A. doubling time B. growth rate C. mitotic index D. replication index

A

Which of the following is not a reactive oxygen species? A. atmospheric oxygen B. peroxides C. singlet oxygen D. superoxide

A

Which of the following is the first step in triglyceride degradation? A. removal of fatty acids B. β-oxidation C. breakage of fused rings D. formation of smaller peptides

A

Which of the following is the most acidic location in a mitochondrion? A. the intermembrane space B. the matrix C. within the outer membrane D. within the thylakoid

A

Which of the following is the step in which CO2 enters the light-independent reactions (Calvin cycle)? A. fixation B. reduction C. regeneration D. transition

A

Which of the following molecules is not produced during the breakdown of phospholipids? A. glucose B. glycerol C. acetyl groups D. fatty acids

A

Which of the following processes is not involved in the conversion of organic nitrogen to nitrogen gas? A. nitrogen fixation B. ammonification C. nitrification D. denitrification

A

Which of these elements is not a micronutrient? A. C B. Ca C. Co D. Cu

A

Which property best describes the hydrocarbon TAILS in the plasma membrane? A. hydrophobic B. polar C. hydrophilic D. amphipathic

A

dehydration synthesis

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Based on what you know about different metabolic types of microbes, what would be the carbon, energy, and electron requirements for a chemoorganoautotroph?

A chemoorganoautotroph would be an organism that used chemical reactions of organic molecules to gain energy and electrons but is also capable of fixing inorganic molecules to produce organic molecules.

Disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

Match each term with its best example. A. chemoautotroph B. chemoheterotroph C. photoautotroph D. photoheterotroph i. animals ii. iron-oxidizing bacteria iii. purple sulfur bacteria iv. green nonsulfur bacteria

A ii, B i, C iii, D iv

Match each description with the best definition. A. chemoautotroph B. chemoheterotroph C. photoautotroph D. photoheterotroph i. uses light energy and an inorganic carbon source ii. uses chemical energy and an inorganic carbon source iii. uses light energy and an organic carbon source iv. uses chemical energy and an organic carbon source

A ii, B iv, C i, D iii

Match each molecule with the best description. A. FAME B. MALDI-TOF C. PLFA D. proteomic analysis i. uses saponification to release fatty acids for further analysis to produce gas chromatograms ii. produces gas chromatograms of fatty acids to compare with references iii. uses HPLC, digestion, then mass spectrometry iv. produces a mass spectrum to compare with references without requiring HPLC

A ii, B iv, C i, D iii

Match each molecule with the class of macromolecules it exemplifies. A. β-carotene B. chitin C. hemoglobin D. RNA i. protein ii. lipid iii. nucleic acid iv. carbohydrate

A ii, B iv, C i, D iii

Match each process with the best definition. A. aerobic respiration B. anaerobic respiration C. fermentation i. uses an electron transport chain with an inorganic molecule such as SO42- as the terminal electron acceptor ii. regenerates NAD+ for glycolysis by donating an electron to an endogenous organic molecule, often pyruvate iii. uses an electron transport chain with O2 as the terminal electron acceptor

A iii, B i, C ii

Match each molecule with a type of functional group it contains. A. NH2CH2CH3 B. CH3COCH3 C. CH3CH2OH D. CH3CH2COOH E. CH3CH2SH i. ketone ii. carboxylic acid iii. amino iv. sulfhydryl v. hydroxyl

A iii, B i, C v, D ii, E iv

Match each word with the best definition. A. apoenzyme B. coenzyme C. cofactor D. holoenzyme i. an inorganic enzyme helper molecule ii. an active enzyme with its coenzyme or cofactor iii. an inactive enzyme lacking its coenzyme or cofactor iv. an organic enzyme helper molecule

A iii, B iv, C i, D ii

Match each molecule with type of monomer it exemplifies. A. adenosine triphosphate B. alanine C. cholesterol D. ribose i. amino acid ii. lipid iii. monosaccharide iv. nucleotide

A iv, B i, C ii, D iii

Match each term with the best definition. A. primary protein structure B. secondary protein structure C. tertiary protein structure D. quaternary protein structure i. created from localized folding that creates helices and sheets primarily stabilized by hydrogen bonding ii. produced by joining more than one polypeptide chain by interactions including hydrogen bonding, hydrophobic interactions, disulfide bonds, and ionic interactions iii. created from interactions between relatively distant amino acids, including hydrogen bonding, hydrophobic interactions, disulfide bonds, and ionic interactions iv. refers to the sequence of amino acids connected by peptide bonds

A iv, B i, C iii, D ii

Match each type of fermentation with a microbe that uses it. A. acetone-butanol-ethanol B. alcohol C. butanediol D. lactic acid E. mixed acid i. Candida, Saccharomyces ii. Escherichia, Shigella iii. Klebsiella, Enterobacter iv. Clostridium acetobutylicum v. Streptococcus, Lactobacillus

A iv, B i, C iii, D v, E ii

Match each reaction with the place that it occurs in eukaryotic cells. A. electron transport chain of cellular respiration B. glycolysis C. Krebs cycle D. light-independent reactions (Calvin cycle) E. light reactions of photosynthesis i. stroma of chloroplast ii. cytoplasm iii. thylakoid membrane iv. inner mitochondrial membrane v. mitochondrial matrix

A iv, B ii, C v, D i, E iii

Match each type of fermentation with some of its end products. A. alcohol B. butanediol C. mixed acid D. propionic acid i. acetic acid and other products ii. succinic acid and other products iii. formic acid, lactic acid, and other products iv. ethanol and CO2 only

A iv, B iii, C ii, D i

chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

glycoprotein

A protein with one or more carbohydrates covalently attached to it.

What is a unit membrane?

A unit membrane is the standard membrane of plasma membranes and eukaryotic organelles. Unit membranes have a phospholipid bilayer structure.

Match each microbe with the best description. A. Bacillus firmus B. Ferroplasma C. Geobacillus D. Halomonas i. acidophile ii. alkaliphile iii. halotolerant iv. thermophile

A. ii., B. i., C. iv., D. iii

Match each type of microbe with the best description. A. hyperthermophile B. mesophile C. psychrophile D. psychrotroph i. temperature range for growth: approximately 0-15 °C ii. temperature range for growth: approximately 80-110 °C iii. temperature range for growth: approximately 50-80 °C iv. optimal temperature range for growth: approximately 20-40 °C v. grows well between 4 °C and 25 °C

A. ii., B. iv., C. i., D. v., E. iii

Match each type of medium with the best description. A. chemically defined medium B. complex medium C. differential medium D. enriched medium E. selective media i. a medium with growth factors added to promote the growth of fastidious organisms ii. a medium made from the digests of yeasts, meats, or plants, meaning that the exact composition is unknown iii. a medium that favors the growth of some organisms over others iv. a medium for which the entire composition is exactly known v. a medium that allows colonies of bacteria to be distinguished based on one or more characteristics

A. iv., B. ii., C. v., D. i., E. iii

Match each type of organism with the best description of its oxygen requirements. A. aerotolerant anaerobes B. facultative anaerobe C. microaerophile D. obligate aerobe E. obligate anaerobe i. an organism that requires an oxygen-free environment ii. an organism that requires oxygen to survive iii. an organism that requires a low concentration of oxygen (less than the oxygen concentration in the atmosphere) iv. an organism that grows equally well with or without oxygen v. an organism that can grow without oxygen but that grows best with oxygen

A. iv., B. v., C. iii., D. ii., E. i

Cyclic photophosphorylation produces ________.

ATP

The molecule with is often referred to as the cell's energy currency is called __________________.

ATP

The NADH and FADH2 produced during β-oxidation are used to make ________.

ATP by oxidative phosphorylation

The passage of hydrogen ions through ________ down their electrochemical gradient harnesses the energy needed for ATP synthesis by oxidative phosphorylation.

ATP synthase

________ tissue stores energy in the form of triglycerides.

Adipose (fat)

1. Using the standard equation to calculate number of cells at each generation, how many cells would be present after four generations in a population undergoing exponential growth that started with a population of two cells? How does this compare with the size after four generations of a similar population that started with eight cells?

After four generations, a population of two cells would have grown to 32 cells. After four generations, a population of eight cells would have grown to 128 cells.

Is life dependent on the carbon fixation that occurs during the light-independent reactions of photosynthesis? Explain.

Although much of life, including the life forms with which we are most familiar, are dependent on the organic carbon molecules produced during CO2 fixation that occurs during the light-independent reactions, there are some more unusual ecosystems that are not dependent on photoautotrophy for CO2 fixation. These ecosystems, like the deep-sea hydrothermal vent ecosystem, are completely devoid of light and depend instead on the CO2 fixation carried out by chemoautotrophs. Many of these also use the Calvin cycle, but others use alternative CO2 fixation pathways.

Compare the structures of starch, glycogen, and cellulose. Explain why humans cannot use cellulose as a major source of energy even though it contains glucose molecules.

Although starch, glycogen, and cellulose are all polymers of glucose, they have different structures, resulting in different properties. Starch consists of two types of chains, a straight chain (amylose) and a branched chain (amylopectin). Glycogen consists of one type of chain, which is more branched than amylopectin. Cellulose is not branched but has linkages between its linear chains that make it strong. Because cellulose has different glycosidic linkages than those of starch and glycogen, a different enzyme is needed to break it down and human do not produce this enzyme.

Beta-amyloid and Tau proteins have been implicated in which of the following diseases?

Alzheimer's disease

apoenzyme

An enzyme lacking a cofactor or coenzyme

Why would an organism perform cyclic phosphorylation instead of noncyclic phosphorylation?

An organism would prefer cyclic phosphorylation when its needs for ATP outweigh its needs for NADPH or NADH. Perhaps it is not doing much biosynthesis, so it does not need to make much NADPH or NADH.

1. Which of the following is an important component of insect exoskeletons? A. cellulose B. chitin C. glycogen D. starch

B

A triglyceride contains which subcomponents? A. a glycerol and two sugars B. a glycerol and three fatty acids C. a glycerol and two fatty acids D. a glycerol and three sugars

B

ATP is produced through oxidative phosphorylation when which of the following occurs? A. FADH2 donates electrons to succinate dehydrogenase B. H+ moves through ATP synthase C. NADH donates electrons to NADH dehydrogenase D. the light-independent reactions fix CO2

B

Beta-amyloid and Tau proteins have been implicated in which of the following diseases? A. Cystic fibrosis B. Alzheimer's disease C. Multiple sclerosis D. Rheumatoid arthritis

B

During the Krebs cycle, FAD is reduced to which of the following? A. FADH B. FADH2 C. NADH D. NADH2

B

During the light-dependent reactions, which molecule loses an electron? A. a light-harvesting pigment molecule B. a reaction center pigment molecule C. NADPH D. 3-phosphoglycerate

B

During which of the following is ATP not made by substrate-level phosphorylation? A. Embden-Meyerhof pathway B. Transition reaction C. Krebs cycle D. Entner-Doudoroff pathway

B

Each pyruvate molecule contains how many carbon atoms? A. two B. three C. four D. six

B

Enzymes work by which of the following? A. increasing the activation energy B. reducing the activation energy C. making exergonic reactions endergonic D. making endergonic reactions exergonic

B

In batch culture, how does the log phase of the bacterial growth curve appear? A. exponential on a semi-log scale B. linear on a semi-log scale C. logarithmic on an arithmetic scale D. logarithmic on a semi-log scale

B

Molecules bearing both polar and nonpolar groups are said to be which of the following? A. hydrophilic B. amphipathic C. hydrophobic D. polyfunctional

B

The Krebs cycle begins with the addition of acetyl CoA to which of the following? A. citric acid B. oxaloacetate C. ribulose bisphosphate D. succinate dehydrogenase

B

The reaction that breaks down ATP to form ADP and inorganic phosphate is classified as which of the following? A. endergonic B. exergonic C. nonspontaneous D. reduction

B

What is the goal number of CFUs on a spread plate if a serial dilution is done correctly? A. 1-10 per plate B. 30-300 per plate C. 400-900 per plate D. 1000 or more per plate

B

Which are two products of the light-dependent reactions are ________. A. glucose and NADPH B. NADPH and ATP C. glyceraldehyde 3-phosphate and CO2 D. glucose and oxygen

B

Which fermentation product is important for making bread rise? A. ethanol B. CO2 C. lactic acid D. hydrogen gas

B

Which of the following are organic molecules that help enzymes work correctly? A. cofactors B. coenzymes C. holoenzymes D. apoenzymes

B

Which of the following best describes FtsZ? A. a cytoskeletal protein in eukaryotic cells B. the protein that assembles the Z ring, which forms a divisome before division by binary fission C. the protein that forms within the central structure of the new cell wall and septum that separates the daughter cells during binary fission D. the protein that gives structure to spirochetes, contributing to their unusual shape and motility

B

Which of the following best describes catabolic pathways? A. They always absorb energy. B. They break down large molecules into smaller components. C. They build up large molecules from smaller components. D. They must be coupled with the breakdown of ATP.

B

Which of the following best describes culture density? A. another term for a batch culture B. the number of cells per unit volume C. the reproducible pattern of growth D. the total number of cells

B

Which of the following best describes the enzymes of extreme alkaliphiles? A. They have many acidic amino acids. B. They have relatively high isoelectric points. C. They have relatively high numbers of negatively charged surface amino acids. D. They have the ability to pump protons out of cells.

B

Which of the following characteristics/compounds is not considered to be a phenotypic biochemical characteristic used of microbial identification? A. poly-β-hydroxybutyrate B. small-subunit (16S) rRNA gene C. carbon utilization D. lipid composition

B

Which of the following is a pathway that breaks down glucose in some microbes? A. the Calvin cycle B. the Entner-Doudoroff pathway C. the Krebs cycle D. the tricarboxylic acid cycle

B

Which of the following is not a commercially important fermentation product? A. ethanol B. pyruvate C. butanol D. penicillin

B

Which of the following is not a common step in preparing a pour plate to make a count of microbial numbers? A. A serial dilution is performed. B. Bacteria are spread across the agar, using a sterile spreader. C. Bacteria are mixed with warm agar and poured onto a Petri plate, then swirled. D. The sample is allowed to grow, then colonies are counted.

B

Which of the following is not a lipid? A. a fatty acid B. a glyceraldehyde C. a wax D. an isoprenoid

B

Which of the following is not an electron carrier within an electron transport system? A. flavoprotein B. ATP synthase C. ubiquinone D. cytochrome oxidase

B

Which of the following is not an example of an enzyme used to detoxify reactive oxygen species? A. catalase B. permeases C. peroxidases D. superoxide dismutases

B

Which of the following is the best example of a micronutrient? A. phosphorus B. potassium C. carbon D. nitrogen

B

Which of the following is the correct order of phases of growth in the growth curve of a batch culture? A. death/decine -> lag -> log -> stationary B. lag -> log -> stationary -> death/decline C. log -> lag -> stationary -> death/decline D. stationary -> log -> lag -> death/decline

B

Which of the following is true of using a Petroff-Hausser chamber to do a direct cell count? A. Identical squares, all the same size, are etched into the slide. B. If the sample was diluted, then the concentration must be corrected accordingly. C. It is not necessary to know the volume of the sample added to the slide. D. The chamber does not resemble a hemocytometer.

B

Which of the following products is made during Embden-Meyerhof glycolysis? A. NAD+ B. pyruvate C. CO2 D. two-carbon acetyl

B

Which range of the electromagnetic spectrum is considered photosynthetically active radiation? A. from ultraviolet to near infrared B. from visible light to near infrared C. in near infrared only D. in visible light only

B

Which site on an enzyme is where substrates bind? A. the activation site B. the active site C. the catalyst site D. the lock and key site

B

Which structure separates new daughter cells in binary fission? A. the crescent B. the division septum C. the FtsZ D. the spindle apparatus

B

Which type of system is used to maintain bacteria in a relatively constant environment, allowing them to stay in the log phase of growth? A. bacteriostat B. chemostat C. maintenance state D. stable state

B

1. Why do researchers often work with bacteria in the log phase of bacterial growth in a batch culture, rather than in other phases?

Bacteria in the log stage are most commonly used because of their relatively consistent characteristics (i.e., growth and metabolism) and susceptibility to disinfectants and antibiotics.

Microorganisms can thrive under many different conditions, including high-temperature environments such as hot springs. To function properly, cell membranes have to be in a fluid state. How do you expect the fatty acid content (saturated versus unsaturated) of bacteria living in high-temperature environments might compare with that of bacteria living in more moderate temperatures?

Bacteria living in hot springs will likely have a greater saturated fatty acid content than bacteria living in more moderate temperatures. Saturated fatty acids experience stronger mutual attractive forces due to their relatively straight hydrocarbon chains, thus many are solids near room temperature and only become fluid when adequately heated. The "kinked" hydrocarbon chains of unsaturated fatty acids make them less strongly attracted to one another, and they are fluid at room temperature. At elevated temperatures, the mutual attractions among unsaturated fatty acids may be weakened to the point that the membrane dissociates.

1. Where are barophilic organisms found?

Barophilic organisms require high pressures to grow, so they are found deep in the ocean.

What is the function of molecules like NAD+/NADH and FAD/FADH2 in cells?

Because electrons cannot exist in an unbound form in cells, these molecules serve as mobile electron carriers in cells, accepting electrons from some molecules and shuttling them to others.

Why is the Krebs cycle called the citric acid cycle?

Because the acetyl group is added to a C4 intermediate producing citric acid

What are similarities between cholesterol and hopanoids? What types of organisms use them? What are some other molecules with similar functions?

Both cholesterol and hopanoids are used to stabilize the cell membrane. Hopanoids are found in prokaryotic cell membranes and cholesterol is found in eukaryotic cell membranes. Other molecules with similar functions are phytosterols, used by plants, and ergosterols, used by fungi.

Heating a protein sufficiently may cause it to denature. Considering the definition of denaturation, what does this statement say about the strengths of peptide bonds in comparison to hydrogen bonds?

By definition, denaturation involves the loss of higher-order protein structure (secondary, tertiary, quaternary). If heating a protein can disrupt, for example, its secondary structure (due to hydrogen bonding) but not its primary structure (due to covalent bonding, specifically, the formation of peptide bonds), this indicates that peptide bonds are much stronger than hydrogen bonds.

1. A triglyceride contains which subcomponents? A. a glycerol and two fatty acids B. a glycerol and two sugars C. a glycerol and three fatty acids D. a glycerol and three sugars

C

1. C6H12O6 is an example of which type of molecule? A. amino acid B. fatty acid C. monosaccharide D. nucleotide

C

1. Chitin is a polymer of which of the following? A. amylase and amylopectin B. glycosaminoglycan C. N-acetyl glucosamine D. N-acetyl muramic acid

C

1. Dextromethorphan and levomethorphan are best described as which of the following? A. achiral B. biologically identical C. enantiomers D. structural isomers

C

1. The building blocks of polymers are called which of the following? A. inorganic molecules B. macromolecules C. monomers D. nucleic acids

C

1. Which best describes oligopeptides? A. a molecule consisting of two amino acids B. long chains of amino acids C. polymers of about 20 amino acids D. polymers of about 50 amino acids

C

1. Which describes the hydrocarbon tails in the plasma membrane? A. amphipathic B. hydrophilic C. hydrophobic D. polar

C

1. Which monomers make up lipids? A. amino acids B. fatty acids C. lipids do not consist of monomers D. monosaccharides

C

1. Which of the following best describes the difference between steroids and sterols? A. Steroids are the most common type of sterol. B. Steroids contain rings, whereas sterols do not. C. Sterols are a type of steroid with an OH group. D. Sterols are present in prokaryotes and steroids are not.

C

1. Which of the following is not one of the four major types of carbon-based macromolecules found in cells? A. carbohydrates B. lipids C. macronutrients D. nucleic acids

C

1. Which of the following is the typical, stable shape of glucose in cells? A. a branched chain B. a double ring C. a ring D. a tetrahedron

C

1. Which term specifically describes fatty acids that do not have any double bonds, triple bonds, or rings? A. esterified B. polyunsaturated C. saturated D. unsaturated

C

By definition, carbohydrates contain which elements? A. carbon and hydrogen B. carbon, hydrogen, and nitrogen C. carbon, hydrogen, and oxygen D. carbon and oxygen

C

Carotenoids are pigments that are which of the following colors? A. blue/green B. green/orange C. orange/yellow/red D. purple/blue

C

Caseinase is which type of enzyme? A. phospholipase B. lipase C. extracellular protease D. intracellular protease

C

Food spoilage is often caused by which type of microbe? A. mesophiles B. psychrophiles C. psychrotrophs D. thermophiles

C

The initial cells added to a batch culture are called which of the following? A. the batch B. the culture C. the inoculum D. the lagging cells

C

To which of the following does a competitive inhibitor most structurally resemble? A. the active site B. the allosteric site C. the substrate D. a coenzyme

C

Which is a common electron acceptor in catabolic reactions? A. ATP B. FADH2 C. NAD+ D. NADPH

C

Which is the source of the energy used to make ATP by oxidative phosphorylation? A. oxygen B. high-energy phosphate bonds C. the proton motive force D. Pi

C

Which method involves the generation of gas phase ions from intact microorganisms? A. FAME B. PLFA C. MALDI-TOF D. Lancefield group testing

C

Which microbial pathogen has an unusually long doubling time? A. Bacillus subtilis B. Escherichia coli C. Mycobacterium leprae D. Salmonella typhimurium

C

Which molecule typically serves as the final electron acceptor during fermentation? A. oxygen B. NAD+ C. pyruvate D. CO2

C

Which of the following are inorganic molecules that bind to enzymes? A. apoenzymes B. coenzymes C. cofactors D. holoenzymes

C

Which of the following best defines chemiosmosis? A. the disruption of the inner mitochondrial membrane, which dissipates energy B. the movement of electrons from one acceptor to another C. the movement of hydrogen ions through ATP synthase D. the series of reactions that regenerate oxaloacetate

C

Which of the following best describes why extracellular polymeric substances are important? A. They are chemicals produced as part of the immune response to microbial invasion. B. They are components of a biofilm secreted by the host cells as an immune response to wall off the pathogens. C. They are components of a biofilm secreted by the microbes present. D. They are secreted by free-living bacteria as virulence factors to allow them to penetrate the bloodstream.

C

Which of the following describes a molecule that had an electron removed? A. anabolized B. electronated C. oxidized D. reduced

C

Which of the following groups varies among different amino acids? A. hydrogen atom B. carboxyl group C. R group D. amino group

C

Which of the following is NOT considered a functional group? A. hydroxyl B. aldehyde C. sterol D. ketone

C

Which of the following is an inhibitor that binds to the active site of an enzyme? A. a noncompetitive inhibitor B. an allosteric inhibitor C. a competitive inhibitor D. an uncompetitive inhibitor

C

Which of the following is not a name for the cycle resulting in the conversion of a two-carbon acetyl to one ATP, two CO2, one FADH2, and three NADH molecules? A. Krebs cycle B. tricarboxylic acid cycle C. Calvin cycle D. citric acid cycle

C

Which of the following is the group of archaea that can use CO2 as their final electron acceptor during anaerobic respiration, producing CH4? A. methylotrophs B. methanotrophs C. methanogens D. anoxygenic photosynthesizers

C

Which of the following is the purpose of fermentation? A. to produce carbon dioxide B. to produce large quantities of additional energy C. to regenerate NAD+ D. to regenerate oxygen

C

Which of the following is the term for free-living bacteria? A. biofilms B. pathogenic C. planktonic D. sessile

C

Which of the following media is commonly used to determine the oxygen requirements of a bacterial species? A. chocolate agar medium B. Mueller-Hinton agar medium C. thioglycolate medium D. tryptic soy medium

C

Which of the following occurs when molecules are broken down using β-oxidation? A. Carbon dioxide is removed. B. Three carbon propyl groups are removed. C. Two carbon acetyl groups are removed. D. Two carbon acyl groups are removed.

C

Which type of organism can survive at great depths in the ocean? A. acidophilic B. barophilic C. barotolerant D. halophilic

C

Why is the actual ATP yield of aerobic respiration often less than the maximum possible yield of 38 ATP? A. Aerobic respiration competes with anaerobic respiration for energy. B. Aerobic respiration competes with fermentation for energy. C. In eukaryotes, energy is used to move molecules across membranes. D. No organisms complete all parts of aerobic respiration.

C

Why are carbon, nitrogen, oxygen, and hydrogen the most abundant elements in living matter and, therefore, considered macronutrients?

Carbon, nitrogen, oxygen, and hydrogen have low atomic numbers. They can form strong bonds with other atoms, so they are present in large amounts in living matter. Cells require them in large amounts to make biomass and biomolecules, so they are considered macronutrients.

1. Why is it helpful for some bacteria, such as Staphylococcus aureus, to produce virulence factors during the stationary phase of growth in a batch culture?

Cells enter the stationary phase because their environment has become less favorable for growth because of increased concentrations of waste products and/or reduced availability of nutrients and oxygen. By producing virulence factors, bacteria may increase their ability to spread to new locations. For example, S. aureus produces enzymes that help it break down tissues to more easily move to new locations.

What characteristics cause an organism to be classified as a chemoheterotroph?

Chemotrophs get their energy from chemical reactions. Heterotrophs obtain preformed organic molecules and cannot build organic molecules from inorganic molecules. Organisms that consume food (organic molecules) to get energy and organic molecules are chemoheterotrophs.

What is the function of cholesterol in cell membranes?

Cholesterol makes cell membranes more resilient. [While the chapter only mentions that cholesterol strengthens cell membranes, students may also say that cholesterol helps regulate membrane fluidity.]

What would be the consequences to a cell of having a mutation that knocks out coenzyme A synthesis?

Coenzyme A is important as a carrier molecule for the production of acetyl-CoA and other molecules. Without coenzyme A, the tiny two-carbon acetyl group produced by the transition reaction would have difficulty entering the Krebs cycle. The large number of reduced molecules (i.e., NADH, FADH2) normally made during the Krebs cycle would not be made, and intermediates used for amino acid and nucleotide synthesis would not be made.

regulate enzymes by binding to an enzyme's active site, preventing substrate binding

Competitive inhibitors

structural isomer

Compounds that have the same molecular formula but differ in the covalent arrangements of their atoms.

isomers

Compounds with the same formula but different structures.

Compare the photosystems used in cyclic and noncyclic photophosphorylation, as well as the products of each.

Cyclic photophosphorylation uses photosystem I only (PSI or P700). It produces ATP. In contrast, noncyclic photophosphorylation uses photosystem I (PSI or P700) and photosystem II (PSII or P680). Noncyclic photophosphorylation produces ATP and NADPH.

What electron carrier in the electron transport chain can be used to distinguish similar bacterial species?

Cytochrome oxidase, the electron carrier that donates electrons to oxygen, differs among species and can be used in identification.

1. Amino groups are an important component of which of the following macromolecules? A. carbohydrates B. lipids C. nucleic acids D. proteins

D

1. Disulfide bridges are most important in which of the following? A. primary structure of proteins B. secondary structure of proteins C. structure of carbohydrates D. tertiary structure of proteins

D

1. In a protein, which type of chemical linkage joins the amino acids? A. disulfide linkages B. glycosidic linkages or bonds C. hydrogen bonds D. peptide bonds

D

1. In which form do plants generally store sugar molecules? A. cellulose B. chitin C. glycogen D. starch

D

1. Which of the following best describes glucose, fructose, and galactose? A. achiral B. enantiomers C. stereoisomers D. structural isomers

D

1. Which of the following is the best definition of a macronutrient? A. a trace element B. a vitamin C. an organic molecule necessary for life D. the most abundant elements found in living cells

D

1. Which of the following is the best example of a micronutrient? A. carbon B. nitrogen C. phosphorus D. potassium

D

A cell might perform anaerobic respiration for which of the following reasons? A. It lacks glucose for degradation. B. It lacks the transition reaction to convert pyruvate to acetyl-CoA. C. It lacks Krebs cycle enzymes for processing acetyl-CoA to CO2. D. It lacks a cytochrome oxidase for passing electrons to oxygen.

D

Chemotrophs obtain their energy from which of the following? A. inorganic chemical reactions only B. light energy C. organic chemical reactions only D. organic and inorganic chemical reactions

D

Disulfide bridges are most important in which of the following? A. secondary structure of proteins B. structure of carbohydrates C. primary structure of proteins D. tertiary structure of proteins

D

During the catabolism of glucose, which of the following is produced only in the Krebs cycle? A. ATP B. NADH C. NADPH D. FADH2

D

How can enteropathogenic O157:H7 E. coli strain be recognized from other E. coli strains? A. Unlike other E. coli, it cannot ferment lactose. B. Unlike other E. coli, it cannot ferment mannose. C. Unlike other E. coli, it cannot ferment pyruvate. D. Unlike other E. coli, it cannot ferment sorbitol.

D

In which form do plants generally store sugar molecules? A. chitin B. glycogen C. cellulose D. starch

D

Monosaccharides may link together to form polysaccharides by forming which type of bond? A. hydrogen B. peptide C. ionic D. glycosidic

D

Proteomic analysis is a methodology that deals with which of the following? A. the analysis of proteins functioning as enzymes within the cell B. analysis of transport proteins in the cell C. the analysis of integral proteins of the cell membrane D. the study of all accumulated proteins of an organism

D

The amino acids present in proteins differ in which of the following? A. size B. shape C. side groups D. all of the above

D

The biogeochemical cycle of which of the following elements is based on changes in solubility rather than redox chemistry? A. carbon B. sulfur C. nitrogen D. phosphorus

D

When is the pentose phosphate pathway favored over other pathways to break down glucose? A. when biosynthesis is not needed B. when phospholipids are needed C. when the cell has a severe energy deficit and needs energy rapidly D. when the synthesis of nucleic acids and proteins is needed

D

Which best defines the term "persisters?" A. cells that form endospores rapidly when environmental conditions become unfavorable, allowing them to survive in a dormant state without causing disease symptoms B. cells that persist in the log phase for much longer than other cells C. cells that rapidly colonize new environments by releasing virulence factors and moving through tissues, allowing them to contribute to severe systemic infections. D. cells with relatively slow metabolic rates that survive longer than others during the death phase and that can cause chronic infections

D

Which is the location of electron transports systems in prokaryotes? A. the outer mitochondrial membrane B. the cytoplasm C. the inner mitochondrial membrane D. the cytoplasmic membrane

D

Which of the following are enzymes that break down proteins? A. amylases B. oxidases C. oxygenases D. proteases

D

Which of the following best describes the cell membranes of microbes that thrive at low temperatures? A. They have only one layer. B. They have relatively even amounts of saturated and unsaturated fatty acids. C. They have relatively high amounts of saturated fatty acids. D. They have relatively high amounts of unsaturated fatty acids.

D

Which of the following does not occur during cyclic photophosphorylation in cyanobacteria? A. electron transport through an ETS B. photosystem I use C. ATP synthesis D. NADPH formation

D

Which of the following is an indirect method of measuring numbers of bacterial cells? A. a Coulter counter B. a Petroff-Hausser chamber C. microscopic cell count D. turbidity measurements

D

Which of the following is not a common electron acceptor in anaerobic respiration? A. Fe3+ B. H2S C. NO3- D. PO43-

D

Which of the following is not a common way bacteria divide? A. binary fission B. budding C. fragmentation D. sporulation

D

Which of the following is not a product of the Krebs cycle? A. GTP, which is converted to ATP B. NADH C. carbon dioxide D. pyruvate

D

Which of the following is not a product of the Krebs cycle? A. carbon dioxide B. GTP, which is converted to ATP C. NADH D. pyruvate

D

Which of the following is the most common category of bacteria? A. acidophiles B. alkaliphiles C. extreme alkaliphiles D. neutrophiles

D

Which of the following is the name for molecules whose structures are nonsuperimposable mirror images? A. structural isomers B. monomers C. polymers D. enantiomers

D

Which of the following is the purpose of fermentation? A. to make ATP B. to make carbon molecule intermediates for anabolism C. to make NADH D. to make NAD+

D

Which of the following microbes uses light energy to pump hydrogen and sodium? A. Bacteriodetes B. Campylobacter C. Chlamydomonas D. Halobacterium

D

Which of the following molecules is reduced? A. NAD+ B. FAD C. O2 D. NADPH

D

Which of the following pigments are especially useful at great depths, where less light penetrates? A. bacteriorhodopsin and carotenoids B. carotenoids and chlorophylls C. fucoxanthin and carotenoids D. fucoxanthin and phycobilins

D

Which of the following would be the best choice for distinguishing living and dead bacteria in a cell count? A. using a Coulter counter or other electronic counting method B. using a streak plate, spread plate, or pour plate C. using gram staining or a similar method D. primary and secondary fluorescent stains

D

Which term specifically describes fatty acids that ONLY contain single bonds and have a resulting linear structure? A. polyunsaturated B. unsaturated C. esterified D. saturated

D

How can fermentation be used to differentiate various types of microbes?

Different types of microbes use different fermentation pathways. The production of particular fermentation products can be monitored. For example, pH indicators can be used to detect acid production due to mixed acid fermentation. Gas production is typically visualized by using an inverted Durham tube in a liquid-broth tube to trap gas. Additionally, microbes can be differentiated according to the substrates they can ferment. Providing microbes different carbon sources and looking for acid and/or gas production is an easy way to see this. For example, the ability to ferment mannitol differentiates Staphylococcus aureus from other staphylococci.

Ether

Disaccharides polysaccharides lipids

During glycolysis, how many ATP molecules are consumed and how many are produced?

During glycolysis, two ATP molecules are consumed and four ATP molecules are produced. There is a net gain of two ATP molecules.

Which of the following describes lipids? A. a source of nutrients for organisms B. energy-storage molecules C. molecules having structural role in membranes D. molecules that are part of hormones and pigments E. all of the above

E

The bacterium E. coli is capable of performing aerobic respiration, anaerobic respiration, and fermentation. When would it perform each process and why? How is ATP made in each case?

E. coli has the genes necessary to do all three processes. Therefore, the triggers to switch from one form of metabolism to another are environmental. Aerobic respiration is preferred and is performed if oxygen is present because this type of metabolism results in the most ATP (up to 38 molecules) being made per glucose molecule, most (34 ATP molecules) of which is made during oxidative phosphorylation. If oxygen becomes depleted, then anaerobic respiration is next preferred if there is a suitable inorganic electron acceptor available. This is because this type of metabolism results in the next largest number of ATP molecules being made per glucose molecule. Should E. coli lack both oxygen and a suitable inorganic terminal electron acceptor, then its last resort is fermentation. Fermenting organisms are inefficient at making ATP from glucose; they make only two ATP molecules per glucose molecule by substrate-level phosphorylation during glycolysis.

What is name of the type of glycolysis found in animals and most common microbes?

Embden-Meyerhof-Parnas (EMP) pathway

activation energy

Energy needed to get a reaction started

lipid functions

Energy storage membrane structure insulation hormones pigments

carbohydrate functions

Energy storage receptors food structural role in plants fungal cell walls exoskeletons of insects

protein functions

Enzymes structure receptors transport structural role in the cytoskeleton of a cell and the extracellular matrix

How can human activity lead to eutrophication?

Eutrophication results from the introduction by humans of an excess amount of a nutrient that is normally limiting to an aquatic environment. Examples include the introduction of excess nitrogen by runoff from agricultural lands using nitrogen-rich fertilizer as well as the introduction of excess phosphorus due to the use of phosphate-rich detergents. This leads to an algal bloom. When these algae die, they decompose, making the water column underneath anaerobic. This is detrimental to aquatic plants, fish, and other aquatic organisms that need oxygen to survive.

Name 3 sets of electron carriers

FAD/FADH2 NAD+/NADH NADP+/NADPH

A change in one amino acid in a protein sequence always results in a loss of function.

False

A denatured protein has lost its primary structure

False

A triglyceride is formed by joining three glycerol molecules to a fatty acid backbone in a dehydration reaction.

False

Competitive inhibitors bind to allosteric sites.

False

Fermentation is necessary because it provides additional energy compared with glycolysis alone.

False

Glycolysis requires oxygen or another inorganic final electron acceptor to proceed.

False

Halotolerant microbes cannot grow without high concentrations of salt.

False

Lancefield group tests can identify microbes using antibodies that specifically bind cell-surface proteins.

False

Lipids are a naturally occurring group of substances that are not soluble in water but are freely soluble in organic solvents.

False

MacConkey agar can be used to select for the growth of gram-positive bacteria, making it especially useful to study Enterobacteriaceae.

False

Photosynthesis always results in the formation of oxygen.

False

Polysaccharides generally have a sweet taste.

False

The presence of poly-β-hydroxybutyrate granules is used in the classification of species of Pseudomonas bacteria.

False

The structure of β-pleated sheets is maintained by covalent bonds and ionic interactions.

False

Two molecules containing the same types and numbers of atoms but different bonding sequences are called enantiomers.

False

1. Why might you need to enrich media?

Fastidious microbes need particular specialized vitamins, growth factors, or other nutrients added to media. When these are added, the medium is called an enriched medium.

People often think of fats as unhealthy and something that they should avoid. What are some reasons that fats are important in the human diet? Give at least three reasons.

Fats are important in building cell membranes. There are phospholipids forming the membrane bilayer and cholesterol within the membrane. Adipose (fat) tissue provides insulation, cushioning, and contouring. Fats are important in energy storage. Because fat is hydrophobic, it can be very tightly packed and takes up less space than glycogen (which associates with water molecules). Animals obtain energy by oxidizing organic molecules. Because fats are more reduced than carbohydrates or proteins, more energy can be extracted from them. Fats also serve additional purposes while storing energy, such as providing cushioning and insulation.

Compare the energy produced by fermentation with that produced by aerobic respiration.

Fermentation produces a net gain of two ATP molecules. In contrast, aerobic respiration produces a maximum of 38 ATP molecules.

Glycolysis Carbon Flow Molecules of Reduced Coenzymes Net ATP by substrate level phosphorylation Net ATP by oxidative phosphorylation Max ATP

Glucose -> 2 pyruvate 2 NADH 2 ATP 6 ATP from 2 NADH 8 ATP

1. ________ organisms do not require high salt concentrations for growth but can grow in salty environments.

Halotolerant

________ is an important globular protein that has four subunits, including two α peptides and two β peptides.

Hemoglobin

Think about the structure of the plasma membrane and about how proteins form three-dimensional structures. How do you think hydrophobic interactions affect an integral membrane protein? Where would hydrophobic amino acids be located on the protein? How would this differ from the location of hydrophobic amino acids in a protein that is loose in the cytoplasm, such as an enzyme?

Hydrophobic interactions make it energetically favorable for nonpolar amino acids to be in the center of a protein in the cytoplasm, where they will interact with each other instead of with the watery cytoplasm of the cell. The inner layer of the cell membrane is composed of the fatty acid tails of the phospholipids, so it is nonpolar. Therefore, hydrophobic amino acids would tend to be located where they would contact the fatty acid tails in center of the cell membrane rather than the polar phosphate groups on the inner and outer sides of the membrane. Within the hydrocarbon portion of the membrane, nonpolar amino acids would be toward the outside of the protein and polar amino acids may be inside in the case of a protein channel. For parts of the protein toward the outside of the membrane, which interact with the polar heads of the phospholipids and extend into the cell, polar amino acids would be predicted to be on the outside and nonpolar amino acids would be toward the inside of the folded protein.

1. Explain how you would do a serial dilution beginning with 1 mL of your bacterial culture.

If you have 1 mL of culture, then you would add 9 mL to have 10 mL total (a 1:10 dilution). You then take 1 mL of the first dilution and add 9 mL of water to get a 1:100 dilution. You repeat this process as many times as needed to obtain the dilution required.

What are the electron carrier molecules that deliver electrons to the electron transport chain in aerobic respiration?

In aerobic respiration, electrons are provided by NADH and FADH2.

How does the location of ATP synthase differ between prokaryotes and eukaryotes? Where do protons accumulate as a result of the ETS in each cell type?

In prokaryotes, the ATP synthase is located within the cytoplasmic membrane, and protons accumulate outside of the cytoplasmic membrane. In eukaryotes, the ATP synthase is located within mitochondrial inner membrane, and protons accumulate in the mitochondrial intermembrane space.

In prokaryotic cells, where does the electron transport chain of aerobic respiration take place?

In prokaryotic cells, the electron transport chain takes place on the cell membrane because these cells do not have mitochondria.

________ is a branched lipid that is a building block of β-carotene.

Isoprene

transfers remaining electrons from the acetyl group produced during the transition reaction to electron carrier molecules, thus reducing them.

Krebs cycle

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Compare MALDI-TOF, FAME, and PLFA, and explain how each technique would be used to identify pathogens.

MALDI-TOF uses the whole microorganism, which is mixed with a specialized matrix reagent and irradiated. Gaseous ions that the reaction emits are analyzed by a mass spectrometer and compared to a database of reference spectra from known microorganisms. FAME analyzes the fatty acids extracted from the membranes of microorganisms and then chemically altered to form volatile methyl esters. The resulting gas chromatogram is compared with reference chromatograms from known microorganisms. PLFA saponifies phospholipids to release fatty acids, which are then analyzed using FAME to measure lipid profiles against an existing database.

1. Why is MacConkey agar considered both a selective and a differential medium?

MacConkey agar is selective because the bile salts and crystal violet included in the medium favor the growth of gram-negative bacteria while interfering with the growth of gram-positive bacteria. It is differential because bacteria that are able to grow cause the medium to turn red if they ferment lactose, whereas nonfermenters do not cause a color change. In this way, fermenters can be distinguished from nonfermenters.

What are micelles and why is it energetically favorable for them to form?

Micelles are spherical structures that assemble from phospholipids with the phosphate groups toward the outside and the lipid tails toward the inside. This is energetically favorable because the lipid tails are hydrophobic and it would take more energy to keep them in contact with water than in contact with each other.

1. Why are microbes in the stationary phase of growth less susceptible to antibiotics?

Microbes at this stage have slower metabolic activities, so they are less susceptible to antibiotics that target those activities.

What are monosaccharides, disaccharides, and polysaccharides?

Monosaccharides are the simplest, smallest molecules of carbohydrates, called simple sugars. Disaccharides are carbohydrates composed of two monosaccharides linked by a glycosidic bond. Polysaccharides are the largest carbohydrates, polymers made of hundreds of chemically linked monosaccharides.

1. What are the most important signaling molecules for quorum sensing in gram-negative bacteria? How does this compare with the signaling molecules used by gram-positive bacteria?

N-acetylated lactones are the most important signaling molecules used for quorum sensing by gram-negative bacteria. In contrast, the most important signaling molecules used by gram-positive bacteria are small peptides.

In cells, can an oxidation reaction happen in the absence of a reduction reaction? Explain.

No, oxidation reactions cannot happen in the absence of reduction reactions because unbound electrons cannot float around in cells independent of molecules. Thus, when an electron is lost from a molecule during an oxidation reaction, it is picked up by a molecule during a reduction reaction.

bind to allosteric sites, inducing a conformational change in the enzyme that prevents it from functioning

Noncompetitive (allosteric) inhibitors

1. What is the standard way to grow obligate anaerobes in the laboratory?

Obligate anaerobes are killed by oxygen, so they need to be maintained in an oxygen-free environment. This can be accomplished using an anaerobic jar or anaerobic chamber. A candle jar is generally used for capnophiles, specifically because it contains a high CO2 concentration. The oxygen concentration decreases as the candle burns, so it is not completely devoid of oxygen, which is the condition needed for strict anaerobes.

Explain at least three reasons why some cells may not use aerobic respiration even though it produces more energy than other forms of respiration.

One possible reason is that a cell lacks an appropriate cytochrome oxidase to use in an electron transport chain. Cytochrome oxidase is needed to transfer electrons to oxygen. Another possible reason is that the cell may not have mechanisms to protect itself from damage caused by the presence of oxygen. When oxygen is present, reactive oxygen species, such as hydrogen peroxide and the superoxide radical, are present and can damage cells if the cells do not have mechanisms to protect themselves. Finally, the cell may be in an environment in which there is not enough oxygen for it to perform cellular respiration.

1. Staphylococci thrive on human skin. What does this tell you about their environmental requirements?

Organisms that thrive on human skin are generally mesophiles, because the optimal temperature range for these species includes human body temperature. They also need to be able to tolerate salt from sweat, so they are generally halotolerant. Water availability varies on different parts of the skin, as do other environmental factors.

In terms of water and electron donors, what is the difference between oxygenic and anoxygenic photosynthesis?

Oxygenic photosynthesis produces oxygen and anoxygenic photosynthesis does not. Oxygenic photosynthesis involves the use of water to donate an electron, releasing oxygen. In anoxygenic photosynthesis, other electron donors are used.

Which two methods identify microbes by their lipid compositions?

PLFA and FAME

Describe the structure of a typical phospholipid. Are these molecules polar or nonpolar?

Phospholipids are molecules made of glycerol linked to two fatty acid molecules and one phosphate group, which may or may not be substituted. Phospholipids have characteristics that are both polar and nonpolar; they are amphipathic molecules, meaning that they have a nonpolar portion (the fatty acid chains) and a polar portion (the group phosphate).

Draw an example of a type of dehydration reaction (a chemical reaction) important in living organisms.

Polymers are often made using dehydration reactions. For example, amino acids are joined together by removing water (a dehydration reaction).

Where does the transition reaction occur in prokaryotic cells, compared with eukaryotic cells?

Prokaryotic cells do not have mitochondria, so the transition reaction takes place in the cytoplasm. In contrast, in eukaryotic cells, the transition reaction takes place in the mitochondrial matrix.

______________________ is the study of all accumulated proteins of an organisms and can be used as a method to identify bacteria.

Proteomic analysis

What is the relationship between chemiosmosis and the proton motive force?

Proton motive force is the electrochemical gradient generated by some ETS complexes pumping H+ through the membrane, causing there to be a higher H+ concentration on one side of the membrane than the other. The flow of H+ down a concentration gradient (i.e., from an area of higher concentration to an area of lower concentration) through ATP synthase is called chemiosmosis. Chemiosmosis through ATP synthase harnesses the energy of the proton motive force and uses it to make ATP by oxidative phosphorylation.

ester

RCOOR

Explain redox potential and why it is important in understanding the electron transport chain.

Redox potential describes how easily a molecule acquires electrons. A molecule with a more positive redox potential will more readily accept an electron from another molecule, being reduced in the process. In the electron transport chain, an electron is passed from one acceptor to another, with each having a more positive redox potential than the last.

What does a catalyst do?

Reduces activation energy

In considering the symbiotic relationship between Rhizobium species and their plant hosts, what metabolic activity does each organism perform that benefits the other member of the pair?

Rhizobium bacteria fix nitrogen gas, converting it into ammonia, then use this ammonia to make organic nitrogen (amino acids) that they provide for their plant hosts. The plants perform photosynthesis, fixing CO2 into sugar molecules that then is taken up by the Rhizobium bacteria living in nodules associated with their roots.

Describe an example of a microbe being used for bioremediation.

Rhodococcus and Pseudomonas are used to break down harmful compounds, such as those that could be released during an oil spill.

primordial soup experimenters

Stanley Miller Harold Urey

Give an example of a halotolerant species that can cause food poisoning

Staphylococcus aureus and Bacillus cereus are halotolerant and can cause food poisoning. Vibrio cholerae, the causative agent of cholera, is also halotolerant.

optical isomers

Stereoisomers that are non-superimposable mirror images of each other enantiomers

What is the difference between a steroid and a sterol?

Steroids lack an -OH group present in sterols.

Some lipid molecules have a distinctive four-ringed structure and often function as hormones. What is the name for this group of hormones, and what are two examples of molecules in this group?

Steroids, including sterols, have this structure. Cholesterol and steroid hormones are examples.

starch

Storage polysaccharide of plants. branched polymer

Compare the types of interactions that are responsible for the four different levels of protein structure.

Student answers will vary but should include components of the following. Primary protein structure is determined by the sequence of amino acids, which are joined together by peptide bonds. Secondary structure results from hydrogen bonding between amino acids that are relatively close together, forming α-helices and β-pleated sheets. Tertiary structure involves interactions between amino acids that are farther apart and results from hydrogen bonding, hydrophobic interactions, disulfide bonds, and ionic interactions. Quaternary structure results from the same interactions as tertiary structure but involves more than one polypeptide chain.

Explain how the structure of the plasma membrane affects what can pass through it.

Student answers will vary but should include components of the following. The middle of the membrane is hydrophobic, so only small, uncharged molecules can pass through easily. Molecules that are polar, such as water, may pass through if they are sufficiently small. However, even very small ions, such as Na+, are unable to pass without assistance (e.g., by passing through a protein channel). Larger, nonpolar molecules, such as steroid hormones, can pass through the membrane.

When a plasma membrane is damaged, it reseals to keep the lipid bilayer intact. Explain how this process happens and why it is energetically favorable.

Student answers will vary but should include components of the following. The middle of the plasma membrane is a hydrophobic lipid layer. It is energetically favorable for the hydrophobic molecules to contact each other rather than being in contact with the watery material inside and outside the cell. For this reason, it is energetically favorable for the membrane to reseal itself when damaged.

Look at the phospholipid molecule below. Compare the shape of saturated and unsaturated fatty acids and think about what would happen if you packed together many phospholipids with a saturated fatty acids compared with packing together many phospholipids with unsaturated fatty acids. How do you think the plasma membrane might act differently if it has a higher proportion of saturated fatty acids versus a higher proportion of unsaturated fatty acids? picture of phospholipid with one saturated and one unsaturated tail

Student answers will vary but should include the following. Saturated fatty acids can pack tightly because they are straight. In contrast, unsaturated fatty acids are kinked and this causes them to pack less tightly. If the temperature were increased without any changes in the composition of the membrane, then the membrane would become too fluid if it had a high proportion of unsaturated fatty acids. By increasing the amount of saturation in the membrane, organisms can make the membrane more solid as the temperature increases. Organisms can also make the membrane more flexible as the temperature drops by increasing the amount of unsaturation.

Explain the difference between substrate level phosphorylation and oxidative phosphorylation.

Substrate level phosphorylation occurs when two reactions are coupled, one that releases energy and one that uses that energy to form ATP. Oxidative phosphorylation occurs when an electron transport chain is used to perform multiple oxidation reactions, providing the energy to produce ATP.

How does oxidative phosphorylation differ from substrate-level phosphorylation?

Substrate-level phosphorylation involves the direct transfer of a phosphate group on an organic molecule to ADP, creating ATP. In oxidative phosphorylation, the phosphate source is inorganic (Pi). The energy required to accomplish oxidative phosphorylation comes from harnessing the proton motive force generated by the electron transport system, and ATP synthase is required. An ETS, proton motive force, and ATP synthase are not involved in making ATP by substrate-level phosphorylation.

What is substrate-level phosphorylation? When does it occur during the breakdown of glucose to CO2?

Substrate-level phosphorylation is a mechanism to make ATP whereby a high-energy phosphate group from an organic molecule is transferred to ADP, resulting in ATP. It occurs during glycolysis, resulting in the net production of two ATP molecules per one glucose molecule. It also occurs during the Krebs cycle, making one ATP molecule per turn of the cycle, or two per starting glucose.

Why is glucose usually found in nature as a ring rather than as a linear structure?

Sugars can form a ring through the interaction of a hydroxyl group and a carbonyl group. When the ring is the right size for maintaining appropriate bond angles (reducing ring strain), then a ring is more stable than the linear molecule. Glucose has six carbons and can form either a six-membered ring or a five-membered ring.

1. Which group of bacteria commonly divides using fragmentation?

The Actinomycetes commonly divide using fragmentation.

Compare the Embden-Meyerhof-Parnas, Entner-Doudoroff, and pentose phosphate pathways for breaking down glucose.

The Embden-Meyerhof-Parnas pathway (EMP), or glycolysis, is the most common pathway and is found in most cells. The Entner-Doudoroff pathway (ED) can coexist with the EMP pathway in some cells. Other organisms use only the ED pathway. The pentose phosphate pathway occurs in all cells and is useful in biosynthesis. It is especially important when molecules with an odd number of carbons, proteins, and nucleic acids are needed.

Why is the Krebs cycle important in both catabolism and anabolism?

The Krebs cycle is important in catabolism for the production of some ATP and, more importantly, for the production of a significant amount of reduced molecules (NADH and FADH2) that can be subsequently be used to make ATP during respiration. However, the Krebs cycle is also important for the intermediates it produces because these can be used to make amino acids and nucleotides for protein and nucleic acid synthesis, respectively.

The term "dextrose" is commonly used in medical settings when referring to the biologically relevant isomer of the monosaccharide glucose. Explain the logic of this alternative name.

The biologically relevant form of glucose is the "d" optical isomer (right-handed or dexter), which is also the isomeric form that rotates polarized light in the clockwise direction (dextrorotary). Thus, the alternative name for d-glucose combines the isomeric designation with the common sugar suffix: "dextr" + "ose" = "dextrose".

high energy phosphate bond

The bond between two phosphates in an ADP or ATP molecule that readily releases its energy for cellular processes when bond is broken, energy is released to drive endergonic reactions

What is the function of photosynthetic pigments in the light-harvesting complex?

The function of these pigments is to absorb light energy at a given wavelength and then transfer that energy to other light-harvesting pigments until the energy eventually reaches a reaction center pigment.

What is the general strategy used by microbes for the degradation of macromolecules?

The general strategy is to produce extracellular enzymes to degrade large macromolecules outside of cells into smaller components, which can then be taken up by cells and further degraded enzymatically in the cytoplasm.

What is produced by the light-independent reactions (the Calvin cycle) of photosynthesis?

The light-independent reactions of photosynthesis produce glyceraldehyde-3-phosphate. These reactions consume ATP and NADPH, producing ADP, Pi, and NADP+ that can be used for the light reactions. (Note that the last sentence is not explained clearly in the text, although the text mentions that ATP and NADPH are used.)

How are the products of lipid and protein degradation connected to glucose metabolism pathways?

The products of lipid and protein degradation enter glycolysis, the transition reaction, and the Krebs cycle. In the case of triglycerides, for example, the three-carbon glycerol can enter glycolysis, while the acetyl-CoA produced by β-oxidation of fatty acids can enter the Krebs cycle. In the case of proteins, the amino acids released may be deaminated and enter glycolysis, the transition reaction, or the Krebs cycle, depending on the amino acid.

1. There has been considerable concern about finding good ways to treat infections involving biofilms, such as those that develop on medical devices. What characteristics of biofilms complicate the treatment of infections involving biofilms?

The proposed hypotheses include at least three possibilities. First, microbes in biofilms may be less metabolically active and bacteria that are less metabolically active are generally affected less by medications. Second, the extracellular polymeric substances may inhibit the ability of medications and other chemicals to penetrate the biofilm to affect the deeper cells. In addition, microbes in biofilms may have metabolic abilities that help to counteract medications. For example, they may be able to pump out antibiotics using efflux pumps. Finally, microbes in biofilms can exchange resistance genes through horizontal gene transfer.

1. Explain what factors influence the length of the lag phase in a batch culture, and why.

The species present, health of the cells, type of medium, and other factors influence the length of the lag phase. When microbes are first placed into a new culture, they must adjust and repair damage before beginning the log phase of growth. They must produce any enzymes necessary to grow in the new medium, although this will be more rapid if the medium and growth conditions are very similar to their previous growth medium. Damaged cells need to undergo repair before rapid growth can begin.

1. Which enzymes that detoxify reactive oxygen species are present or absent in obligate anaerobes and aerotolerant organisms?

The three major types of enzymes used to detoxify reactive oxygen species are catalases, peroxidases, and superoxide dismutases. Aerotolerant organisms usually have superoxide dismutase, but obligate anaerobes usually lack all these enzymes.

Describe some ways that differences in metabolic abilities can be used to identify microbes.

There are many ways that differences in metabolic abilities can be used to identify microbes. Multiple examples are included in the chapter. For example, an oxidase test can be used to distinguish Pseudomonas aeruginosa and Vibrio cholerae from negative Enterobacteriaceae because they use different cytochrome oxidases. The ability to ferment lactose distinguishes Escherichia coli from some other gram-negative bacteria. Additionally, O157:H7 E. coli can be distinguished from other E. coli strains because it cannot ferment sorbitol. Staphylococcus aureus can be distinguished from other staphylococci because it can ferment mannitol.

1. Why is an enzyme from Thermus aquaticus especially useful for PCR?

Thermus aquaticus is a thermophile; its enzymes function well at high temperatures, making it useful for PCR.

1. What are some ways in which the structures of thermophiles and hyperthermophiles differ in order to help them thrive at high temperatures?

These organisms have greater proportions of unsaturated fatty acids in their membranes, which reduces membrane fluidity. They also have higher proportions of guanine-cytosine nitrogenous bases in their DNA to strengthen hydrogen bonding between the two strands, as well as additional bonds (ionic and covalent) to stabilize their protein structure.

Why are some microbes, including Streptococcus spp., unable to perform aerobic respiration, even in the presence of oxygen?

These organisms lack either genes encoding appropriate complexes and electron carriers in the electron transport system and/or genes encoding one or more enzymes in the Krebs cycle. Because their inability to perform aerobic respiration is genetic, it cannot be overcome even in the presence of oxygen.

How do nitrogen-fixing bacteria benefit plants?

They can be housed in root nodules. They convert atmospheric nitrogen to ammonia.

Why must autotrophic organisms also respire or ferment in addition to fixing CO2?

They respire or ferment so that they can actually access the energy that they have stored in the bonds of the organic molecules that they have synthesized. They are not fixing CO2 into organic molecules simply for the good of the heterotrophs that eat them, but rather for their own needs.

1. What is the following equation used for and what do the variables n, Nn, and N0 refer to? Nn = N02n

This equation is used to calculate the number of cells in a population undergoing binary fission for a particular starting population size. The initial number of cells is N0; n represents the number of generations; and Nn represents the number of cells after n generations.

Identify the functional group or groups in this molecule: CH3CH2CHO

This molecule contains an aldehyde.

What type of chemical reaction is needed to separate triglyceride into three fatty acids and glycerol?

To break down this molecule, water must be added (i.e., a hydrolysis reaction).

Aldehydes, amides, carboxylic acids, esters, and ketones all contain carbonyl groups.

True

All organisms that use aerobic cellular respiration have cytochrome oxidase

True

Cellulose is an important structural component of plant cell walls.

True

Cyclic photophosphorylation produces only ATP, but noncyclic photophosphorylation produces ATP and NADH.

True

E. coli can be distinguished from some if its close gram-negative relatives because it can ferment lactose.

True

Estimates of coliforms in water are often made using most probable number techniques.

True

Fatty acids having no double bonds are called "unsaturated."

True

Fungi can generally thrive in drier environments than can bacteria.

True

MALDI-TOF relies on obtaining a unique mass spectrum for the bacteria tested and then checking the acquired mass spectrum against the spectrum databases registered in the analysis software to identify the microorganism.

True

Mycobacterium tuberculosis can degrade cholesterol, making it more virulent.

True

Nitrogen is fixed to ammonia by cyanobacteria and other microbes.

True

Proteins embedded within the plasma membrane are called integral proteins.

True

Some halotolerant microbes are important causes of food poisoning.

True

Some plants use leghemoglobin to bind oxygen.

True

TRUE or FALSE: Two molecules containing the same types and numbers of atoms but different bonding sequences are called stereoisomers.

True

The MALDI-TOF method includes irradiation of the sample.

True

The largest component of the dry weight of a biofilm is usually extracellular polymeric substances.

True

The light reactions of photosynthesis include an electron transport chain.

True

There are many naturally occurring microbes that have the ability to degrade several of the compounds found in oil.

True

Xanthophylls are a type of isoprenoid.

True

________ fatty acids are usually liquid at room temperature.

Unsaturated

1. ________ is a measure of available moisture.

Water activity

hydrophobic

Water fearing

1. What happens during plasmolysis and what causes it?

When a cell is exposed to a high osmotic pressure, the protoplasm moves away from the cell wall. (More detailed answer students may give if they remember the information from Chapter 3: Plasmolysis occurs when an organism with a cell wall is placed in a hypertonic solution. Water leaves the cell through osmosis, causing the plasma membrane to pull away from the cell wall, containing the reduced contents of the cell.)

1. Mixed bacterial infections can occur that include both facultative anaerobes and obligate anaerobes. What happens when these species coexist?

When facultative anaerobes and obligate anaerobes coexist, the facultative anaerobes use up any oxygen present, which allows the obligate anaerobes to thrive

What are xenobiotics?

Xenobiotics are chemicals produced by humans and released into the environment.

Do eukaryotic organisms typically depend on organic molecules for metabolism?

Yes

Is the electron transport system variable between microbes?

Yes It used for diagnostic purposes to help identify certain pathogens.

Is the α carbon of this molecule chiral? Explain.

Yes, the α carbon of this molecule is chiral because it has four different groups attached to it and, therefore, has two mirror image forms.

The ________ is another name for the flow of electrons in noncyclic photophosphorylation.

Z scheme

Which of the following is an inhibitor that binds to the active site of an enzyme?

a competitive inhibitor

phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group.

triglyceride

a lipid made of three fatty acid molecules and one glycerol molecule adipose tissue

allosteric site

a location other than the active site

adenosine monophosphate (AMP)

a low-energy compound that results from the removal of two phosphate groups from ATP

What is substrate level phosphorylation?

a phosphate group is removed from an organic molecule and is directly transferred to an available ADP molecule, producing ATP.

allosteric sites

a region of the enzyme other than the active site to which a substance can bind

cellular electron carriers

accept high-energy electrons from foods and later serve as electron donors in subsequent redox reactions

What kind of fermentation is used in the production of industrial solvents?

acetone-butanol-ethanol fermentation

What molecule starts the Krebs cycle?

acetyl group

The part of an enzyme to which a substrate binds is called the ________.

active site

Where do substrates bind on an enzyme?

active site

location within the enzyme where the substrate binds

active site

The molecule with is often referred to as the cell's energy currency is called __________________.

adenosine triphosphate

What is the energy currency of the cell?

adenosine triphosphate (ATP)

Candida, Saccharomyces - fermentation type?

alcohol

ethanol and CO2 only

alcohol

What kind of fermentation is used in the production of bread?

alcohol fermentation

Hydroxyl

alcohols monosaccharides amino acids nucleic acids

Waxes contain esters formed from long-chain __________ and saturated __________, and they may also contain substituted hydrocarbons.

alcohols; fatty acids

bind to locations on an enzyme away from the active site, inducing a conformational change that increases the affinity of the enzyme's active site(s) for its substrate(s).

allosteric activators

functional group? - NH2CH2CH3

amino

exemplifies which type of monomer? - alanine

amino acid

Results of Miller-Urey Experiment

amino acid formation

Besides energy and CO2, what are intermediate products of the Krebs Cycle used for?

amino acids cholophylls fatty acids nucleotides

Sulfhydryl

amino acids proteins

amino

amino acids proteins

carboxylic acid

amino acids proteins fatty acids

apoenzyme

an enzyme lacking a necessary cofactor or coenzyme

holoenzyme

an enzyme with a bound cofactor or coenzyme

holoenzyme

an enzyme with the necessary associated cofactor or coenzyme

Processes in which cellular energy is used to make complex molecules from simpler ones are described as ________.

anabolic

Which metabolic pathways synthesizes larger molecules?

anabolic pathways

Is glycolysis aerobic or anaerobic?

anaerobic

An enzyme lacking a cofactor or coenzyme

apoenzyme

an enzyme lacking a necessary cofactor or coenzyme

apoenzyme

an inactive enzyme lacking its coenzyme or cofactor

apoenzyme

To be effective, what does the concentration of a competitive inhibitor need to be?

approximately equal to the substrate concentration

1. The pigment used by Halobacteria to absorb light is called ________.

bacteriorhodopsin

Bacteria most commonly reproduce using which of the following methods?

binary fission

Noncompetitive (allosteric) inhibitors

bind to allosteric sites, inducing a conformational change in the enzyme that prevents it from functioning

allosteric activators

bind to locations on an enzyme away from the active site, inducing a conformational change that increases the affinity of the enzyme's active site(s) for its substrate(s).

noncompetitive inhibitor

binds to the enzyme at an allosteric site, a location other than the active site, and still manages to block substrate binding to the active site by inducing a conformational change that reduces the affinity of the enzyme for its substrate

What are enzymes?

biological catalysts that increase the rate of chemical reactions inside cells by lowering the activation energy required for the reaction to proceed

The use of microbes to remove pollutants from a contaminated system is called ________.

bioremediation

glycosidic bond

bond formed by a dehydration reaction between two monosaccharides

lipoprotein

bonding of molecules of fat and protein

peptide bonds

bonds between amino acids

alcohol fermentation is used in the production of _______________.

bread

formic acid, lactic acid, and other products

butanediol

Klebsiella, Enterobacter - fermentation type?

butanediolacetone-butanol-ethanol

How is the energy of the proton motive force harnessed?

by allowing hydrogen ions to diffuse back through the membrane by chemiosmosis using ATP synthase

How does an enzyme lower activation energy?

by binding to the reactant molecules and holding them in such a way as to speed up the reaction.

macromolecule? - chitin

carbohydrate

aldehyde

carbohydrates

saccharides

carbohydrates

lipid molecules contain

carbon hydrogen oxygen nitrogen sulfur phosphorus

4 most common elements in living things

carbon nitrogen oxygen hydrogen

The molecule central to the carbon cycle that is exchanged within and between ecosystems, being produced by heterotrophs and used by autotrophs, is ________.

carbon dioxide

functional group? - CH3CH2COOH

carboxylic acid

Which metabolic pathways breakdown molecules into smaller ones?

catabolic pathways

2 paths of metabolism

catabolism anabolism

Which of the following methods was used to enhance microbial degradation of oil from the Deepwater Horizon?

chemical dispersants

isoprenoids

chemical modifications of isoprene molecule pharmaceuticals pigments fragrances hydrophobic oils and waxes many bacteria feed on these

Substrates

chemical reactants to which an enzyme binds

iron-oxidizing bacteria

chemoautotroph

animals

chemoheterotroph

A ___________ is a type of system that is used to maintain bacteria in a relatively constant environment, allowing them to stay in the log phase of growth

chemostat

The types of pigment molecules found in plants, algae, and cyanobacteria are ________ and ________.

chlorophylls and carotenoids

What are two other names for the Krebs cycle?

citric acid cycle tricarboxylic acid cycle (TCA)

an organic enzyme helper molecule

coenzyme

organic helper molecules that are required for enzyme action.

coenzyme

What carries the acetyl group to the Krebs Cycle?

coenzyme A

What is the acetyl group attached to before the Krebs Cycle?

coenzyme A

an inorganic enzyme helper molecule

cofactor

Which of the following are inorganic molecules that bind to enzymes?

cofactors

inorganic ions such as iron (Fe2+) and magnesium (Mg2+) that help stabilize enzyme conformation and function.

cofactors

secondary protein structure

coiling or folding of a polypeptide due to H-bonding between amino acids

1. When a spread plate is used to estimate bacterial numbers, the numbers are reported as ________.

colony forming units per milliliter (CFU/mL)

molecule similar enough to a substrate that it can compete with the substrate for binding to the active site by simply blocking the substrate from binding.

competitive inhibitor

Besides oxygen, what does a cell need to carry out aerobic respiration?

complete Krebs cycle an appropriate cytochrome oxidase oxygen detoxification enzymes

electron transport system (ETS)

composed of a series of membrane-associated protein complexes and associated mobile accessory electron carriers. The ETS is embedded in the cytoplasmic membrane of prokaryotes and the inner mitochondrial membrane of eukaryotes.

The final ETS complex used in aerobic respiration that transfers energy-depleted electrons to oxygen to form H2O is called ________.

cytochrome oxidase

Where does glycolysis take place?

cytoplasm

glycolysis - where?

cytoplasm

What happens to pyruvate after glycolysis?

decarboxylated to make a 2-carbon acetyl and NADH

What are the two steps of the transition reaction?

decarboxylation by pyruvate dehydrogenase pyruvate -> acetyl group acetyl attached to coenzyme A

Sulfhydryl groups in amino acids join together to form ________.

disulfide bridges (disulfide bonds)

composed of a series of membrane-associated protein complexes and associated mobile accessory electron carriers.

electron transport system

the last component involved in the process of cellular respiration;

electron transport system (ETS)

What is basic chain of cellular respiration

electrons are transferred from NADH and FADH2 through a series of chemical reactions to a final electron receptor

anabolism

endergonic metabolic pathways involved in biosynthesis simple molecular building blocks into more complex molecules fueled by use of cellular energy

What is the first part of the Embden-Meyerhof-Parnas (EMP) pathway called?

energy investment phase,

What is the second part of the Embden-Meyerhof-Parnas (EMP) pathway called?

energy payoff phase

starch

energy storage polymer in plants

What proteins play an important role in cellular metabolism?

enzymes

Fungi produce ________ in their cell membranes, which serves a similar function as cholesterol in animal cell membranes.

ergosterol

Where is the ETS located in eukaryotes and prokaryotes?

eukaryotes - inner mitochondrial membrane prokaryotes - cytoplasmic membrane

Which type of energetic reactions are coupled in cells.

exergonic and endergonic

catabolism

exergonic pathways breakdown complex molecules into simpler ones Molecular energy stored in the bonds of complex molecules is released

Which best describes bacterial growth during the log phase of the growth curve?

exponential

What does FAME stand for?

fatty acid methyl ester

A FAME analysis involves the conversion of _______ to more volatile _____ for analysis using ____________.

fatty acids, methyl esters, gas chromatography

involves the use of a pathway product to regulate its own further production. The cell responds to the abundance of specific products by slowing production during anabolic or catabolic reactions

feedback inhibition

The process of division by which cells split from a parent filament is called ________.

fragmentation

What happens during the energy payoff phase of glycolysis?

gains 4 ATP G3P is oxidized to pyruvate (2) NAD+ -> (2) NADH

Chemotrophs

get their energy from chemical compounds

What carbon products does glycolysis begin and end with?

glucose -> 2 pyruvate

Total Aerobic Respiration Carbon Flow Molecules of Reduced Coenzymes Net ATP by substrate level phosphorylation Net ATP by oxidative phosphorylation Max ATP

glucose -> 6 CO2 10 NADH, 2 FADH2 4 ATP 34 ATP 38 ATP

Another name for the Embden-Meyerhof-Parnas pathway is ________.

glycolysis

Fermenting organisms make ATP through the process of ________.

glycolysis

most common pathway for the catabolism of glucose;

glycolysis

What type of macromolecule in the cell wall can be used for identification?

glycoproteins

A __________ bond joins two monosaccharides together to form a disaccharide.

glycosidic

Conjugated proteins

have a nonpolypeptide portion that can be a carbohydrate or a lipid important components of membranes

unsaturated fatty acids

have one or more double bonds "kinks" in carbon skeleton

saturated fatty acids

have the maximum number of hydrogen atoms possible and no double bonds straight, flexible backbone

amphipathic

having both a hydrophilic region and a hydrophobic region

an active enzyme with its coenzyme or cofactor

holoenzyme

an enzyme with a bound cofactor or coenzyme

holoenzyme

an enzyme with the necessary associated cofactor or coenzyme

holoenzyme

long carbon chain

hydrocarbon chain organic molecules

macronutrients

hydrogen carbon oxygen nitrogen phosphorus sulfur

What are the four groups bonded to the alpha carbon in an amino acid?

hydrogen atom carboxyl group amine group R

A phospholipid has two parts: a ________________ _____________ made up of _____________ and ________________, and _________________ ____________________

hydrophilic head, phosphate, glycerol, hydrophobic tails

functional group? - CH3CH2OH

hydroxyl

What is MALDI-TOF used for?

identifying an unknown microbe

What is FAME used for?

identifying microbes by their lipid compositions

What is PLFA used for?

identifying microbes by their lipid compositions

Enantiomers

isomers that are mirror images of each other

functional group? - CH3COCH3

ketone

internal carbonyl group

ketone

What kind of fermentation is used in the production of yogurt?

lactic acid

polymer

large compound formed from combinations of many monomers

Polysaccharides

large macromolecules formed from monosaccharides not sweet not water soluble

catabolism

large molecules broken down into smaller ones releases energy

Rhizobia are bacteria that live in the root nodules of plants known as ________.

legumes

1. At low temperatures, membranes become ________ fluid unless they are able to modify their composition.

less

exemplifies which type of monomer? - cholesterol

lipid

macromolecule? - β-carotene

lipid

micelle

lipid molecules that arrange themselves in a spherical form in aqueous solutions

steroids

lipids characterized by a carbon skeleton consisting of four fused rings

fatty acids

long chain hydrocarbons with a carboxyl group at the end

denaturation

loss of normal shape of a protein due to heat or other factor

Adenosine Diphosphate (ADP)

low-energy molecule that can be converted to ATP

What does an enzyme do to activation energy?

lowers it

1. The process of freeze-drying microbes so they can be stored until needed is called ________.

lyophilization

What does MALDI-TOF stand for?

matrix assisted laser desorption ionization time of flight

MALDI-TOF

measures the masses of various components using mass spectrophotometer

Acetate fermentation is used by ________.

methanogens

Methyl

methylated compounds: methyl alcohols methyl esters

Krebs cycle - where?

mitochondrial matrix

Escherichia, Shigella - fermentation type?

mixed acid

What kind of fermentation is used in the production of pharmaceuticals?

mixed acid

succinic acid and other products

mixed acid

steroisomers

molecules in which the atoms are joined in the same order, but the positions of the atoms in space are different

monosaccharides

monomers of carbohydrates classified based on the position of the carbonyl group and the number of carbons in the backbone

exemplifies which type of monomer? - ribose

monosaccharide

Carbohydrates

most abundant biomolecules on earth

glycolysis

most common pathway for the catabolism of glucose;

To be effective, what does the concentration of a noncompetitive inhibitor need to be?

much lower than the substrate concentration

Micronutrients (trace elements)

needed in small amounts sodium potassium magnesium zinc iron calcium molybdenum copper cobalt manganese vanadium

Approximately 78% of the atmosphere is ________.

nitrogen gas [N2]

binds to the enzyme at an allosteric site, a location other than the active site, and still manages to block substrate binding to the active site by inducing a conformational change that reduces the affinity of the enzyme for its substrate

noncompetitive inhibitor

macromolecule? - RNA

nucleic acid

Phosphate

nucleic acids phospholipids ATP

exemplifies which type of monomer? - adenosine triphosphate

nucleotide

Name 6 protein functions

nutrients enzyme storage molecules for carbon storage molecules for nitrogen storage molecules for energy structural components

lipid functions

nutrients storage form for carbon energy-storage molecules membranes hormones

Phototrophs

obtain their energy from light

Feedback inhibition

occurs when the product of a metabolic pathway noncompetitively binds to an enzyme early on in the pathway, ultimately preventing the synthesis of the product

secondary protein structure

occurs when the sequence of amino acids are linked by hydrogen bonds created from localized folding that creates helices and sheets primarily stabilized by hydrogen bonding

coenzyme

organic helper molecules that are required for enzyme action. Like enzymes, they are not consumed and, hence, are reusable. The most common sources of coenzymes are dietary vitamins.

Coenzymes

organic molecules required for proper enzyme function often derived from vitamins

The loss of an electron from a molecule is called ________.

oxidation

How is most of the ATP made during cellular respiration?

oxidative phosphorylation

Which part of glucose catabolism produces most of the ATP?

oxidative phosphorylation

What does a cell require to carry out aerobic respiration?

oxygen as the final electron acceptor

mixed acid fermentation is used in the production of _______________.

pharmaceuticals

What does PLFA stand for?

phospholipid-derived fatty acids

Which of the following is the term for free-living bacteria?

planktonic

cellulose

plant cell walls

The presence or absence of the storage molecule ________ can be used to identify some species of Pseudomonas.

poly-β-hydroxybutyrate

Proteins

polymers formed by the linkage of a very large number of amino acids

Peptides

polymers formed by the linkage of amino acids via dehydration synthesis

glycogen

primary energy storage molecule in animals and bacteria branched polymer

MALDI-TOF

produces a mass spectrum to compare with references without requiring HPLC

FAME

produces gas chromatograms of fatty acids to compare with references

acetic acid and other products

propionic acid

What kind of fermentation is used in the production of Swiss cheese?

propiponic acid

macromolecule? - hemoglobin

protein

quaternary protein structure

protein consisting of more than one amino acid chain

amide

proteins

enzyme

proteins that serve as catalysts for biochemical reactions

______________________ is the study of all accumulated proteins of an organisms and can be used as a method to identify bacteria.

proteomic analysis

Which of the following is not a product of the Krebs cycle?

pyruvate

primary protein structure

refers to the sequence of amino acids connected by peptide bonds

fermentation - how it works?

regenerates NAD+ for glycolysis by donating an electron to an endogenous organic molecule, often pyruvate

Do catabolic pathways require energy or release energy?

release energy

exergonic reactions

release energy do not require energy beyond activation energy to proceed

exergonic

releases energy

dephosphorylation

removal of a phosphate group

Does phosphorylation require energy or release energy?

require

Do anabolic pathways require energy or release energy?

require energy

endergonic reactions

require energy beyond activation energy to occur

endergonic

requires energy

endergonic reaction

requires energy to proceed.

The enzyme responsible for CO2 fixation during the Calvin cycle is called ________.

ribulose bisphosphate carboxylase (RuBisCO)

The enzyme that brings CO2 into the light-independent reactions of photosynthesis, catalyzing the first reaction, is ________.

ribulose bisphosphate carboxylate oxidase (RuBisCO)

Stanley Miller and Harold Urey

scientists who formed amino acids and other simple organic compounds in a laboratory experiment by reacting ammonia, methane, and hydrogen gases mixed with water vapor

Denaturation implies the loss of the __________ and __________ structures without the loss of the __________ structure.

secondary, tertiary, primary

primary protein structure

sequence of a chain of amino acids

primary protein structure

sequence of amino acids

anabolism

small molecules are assembled into larger ones uses energy

1. Turbidity is measured using a ________.

spectrophotometer

Sebum contains wax esters, triacylglycerol, and ________.

squalene

What do cofactors do?

stabilize enzyme conformation and function

Cholesterol is the most common member of the __________ group, found in animal tissues; it has a tetracyclic carbon ring system with a __________ bond in one of the rings and one free __________group.

steroid; double; hydroxyl

sterols

steroids with an OH group

what shapes can the carbon skeletons of organic molecules take?

straight branched ring shaped (cyclic)

light-independent reactions (Calvin cycle) - where?

stroma of chloroplast

The phenotypic identification of microorganisms involves using observable traits like:

structural components such as lipids biosynthetic products such as sugars or amino acids storage compounds such as poly-β-hydroxybutyrate

chitin

structural polymer found in cell walls of fungi and exoskeletons of some animals

cellulose

structural polymer found in plants

catalyst

substance that speeds up the rate of a chemical reaction

What binds to an enzyme's active site?

substrate

How is ATP made during the energy payoff phase of glycolysis?

substrate-level phosphorylation

chemical reactants to which an enzyme binds

substrates

functional group? - CH3CH2SH

sulfhydryl

sulfide-oxidizing bacteria can be found in mine tailings. What substance do they produce that can kill aquatic plants and animals by causing low pH?

sulfuric acid

Sulfuric acid is produced by sulfide-oxidizing bacteria? What harmful effect can this have on the environment?

sulfuric acid can lower aquatic pH

What are the intermediate products of the Krebs cycle used for?

synthesizing: amino acids chlorophylls fatty acids nucleotides

Disulfide bridges are most important in which of the following?

tertiary structure of proteins

What is the induced-fit model?

the active site of the enzyme undergoes conformational changes upon binding with the substrate.

functional groups

the components of organic molecules that are most commonly involved in chemical reactions

Glycolysis

the first step in the breakdown of glucose ATP NADH pyruvate Glycolysis does not use oxygen and is not oxygen dependent.

electron transport system (ETS)

the last component involved in the process of cellular respiration;

native structure

the normal state of a protein structure

Which of the following best describes FtsZ?

the protein that assembles the Z ring, which forms a divisome before division by binary fission

Proteomic analysis

the study of all accumulated proteins of an organism used for bacterial ID

organic chemisty

the study of most carbon-containing compounds

tertiary protein structure

three-dimensional folding pattern of a protein due to side chain interactions

light reactions of photosynthesis - where?

thylakoid membrane

1. Which of the following is the purpose of fermentation? to produce carbon dioxide to regenerate NAD+ to regenerate oxygen to produce large quantities of additional energy

to regenerate NAD+

Krebs cycle

transfers remaining electrons from the acetyl group produced during the transition reaction to electron carrier molecules, thus reducing them.

Another term for triglyceride is ________.

triacylglycerol

organic molecules contain carbon, inorganic compounds do not t/f

true

Which of the following is an indirect method of measuring numbers of bacterial cells?

turbidity measurements

How does ATP store energy?

two high-energy phosphate bonds

heterotrophs

use fixed organic carbon compounds

lithotrophs

use inorganic chemicals

Organotrophs

use organic molecules

What happens during the energy investment phase of glycolysis?

uses 2 ATP splits (1) C6 into (2) C3 (1) glucose into (2) glyceraldehyde 3-phosphate (G3P)

proteomic analysis

uses HPLC, digestion, then mass spectrometry

photoheterotroph

uses light energy and an organic carbon source

PLFA

uses saponification to release fatty acids for further analysis to produce gas chromatograms

In oxygenic photosynthesis, oxygen is released because ________is split to provide an electron to replace one that absorbs a photon of light.

water

ingredients in Miller and Urey's experiment

water methane hydrogen ammonia heat "lightning"

hydrophilic

water loving

The microbe responsible for ethanol fermentation for the purpose of producing alcoholic beverages is ________.

yeast (Saccharomyces cerevisiae)

lactic acid fermentation is used in the production of _______________.

yogurt

The process by which two-carbon units are sequentially removed from fatty acids, producing acetyl-CoA, FADH2, and NADH is called ________.

β-oxidation

Do you think that β-oxidation can occur in an organism incapable of cellular respiration? Why or why not?

β-oxidation is unlikely in an organism incapable of cellular respiration. β-oxidation directly produces a lot of NADH and FADH2 molecules that must be processed by respiration. In addition, the large number of acetyl groups produced by β-oxidation need to be processed by the Krebs cycle, which also requires cellular respiration to process the NADH and FADH2 molecules produced during the Krebs cycle.