Micro ch5, ch6

What type of organism caused the outbreak at Seneca Lake Sprayground? ch5Quiz

Bacterium

Consider the biochemical pathway: A → B → C Enzyme 1 catalyzes A → B Enzyme 2 catalyzes B → C Enzyme 1 can use

Both A and B substrates

Consider the three key central metabolic pathways (glycolysis, pentose phosphate pathway, and the TCA cycle). What three beneficial products of these pathways? (ch6)

ATP precursor metabolites reducing power

Considering the general equation that describes photosynthesis, the rate of the process would be most influenced by the availability of _______ in the atmosphere. (ch6)

CO2

What happens to carbon dioxide after it is released during reactions of the TCA cycle?

It diffuses out of the cell.

Until the optimal temperature is reached, raising the temperature has what effect on the speed of enzymatic reactions? (ch6)

It increases their rate.

What happens to an organism if it lacks one or more enzymes in a given biosynthetic pathway? (ch6)

It must have the end product provided from an external source.

What part of the body is affected with hepatitis? ch5Quiz

Liver

The two 3-carbon molecules glucose is split into are converted through a series of steps into pyruvate. During these steps

NAD+ is converted to NADH.

The electron transport chain is a cluster of membrane-embedded electron carriers that accept electrons from the coenzymes ___ and ___ and then pass these electrons along the chain. (ch6)

NADH FADH2

Hydrogen is transported from other reactions to the electron transport chain by ______.

NADH & FADH2

Consider the biochemical pathway: A → B → C Enzyme 1 catalyzes A → B Enzyme 2 catalyzes B → C If enzyme 2 is inactive, which of the following compounds will accumulate?

Only B

The terminal electron acceptor in aerobic respiration is ______.

Oxygen

Some members of which of the following groups can use inorganic chemicals such as hydrogen sulfide and ammonia for energy? (ch6)

Prokaryotes only

The two 3-carbon molecules that glucose is split into during glycolysis are converted through a series of steps ending in what 3-carbon molecule?

Pyruvate

Identify what investigations would need to be done to eliminate the possibility that patient A contracted hepatitis C by occupational exposure at the facility where she worked. ch5Quiz

Reviewing records for all patients at the facility. Onsite inspection of the facility for evidence of HCV. Observation of the safety practices used by staff at the facility.

Consider the figure showing the relationship between catabolism and anabolism. Which side shows catabolism, and which side shows anabolism? (ch6)

The left side shows catabolism, and the right side shows anabolism.

What is oxidation?

The loss of electrons from a molecule.

Which of the following chemical classes destroy microorganisms by forming chemical bonds that cross-link and inactivate proteins and nucleic acids? ch5

aldehydes

The figure illustrates a type of regulation used by cells to rapidly control certain key enzymes. The arrow labeled "1" points to the _______________ site, and the arrow labeled "2" points to the _____________ site. (ch6)

allosteric active

Cells can quickly alter the activity of certain key enzymes, using other molecules that bind reversibly and distort them. This control of enzymes is called ___ regulation. (ch6)

allosteric (AKA: noncompetitive)

How do aqueous solutions of alcohol usually affect microbes? ch5

by denaturing proteins by damaging lipid membranes

The energy released by ______ is captured by cells to make ATP; this ATP can then be used for biosynthesis, or ______. (ch6)

catabolism, anabolism

High pressure (130,000 psi) is thought to kill microbes by altering their ______. ch5

cell membranes proteins

UV light causes ______ bonds to form between adjacent thymines on the same strand of DNA. ch5Quiz

covalent

Glycolysis takes place in the ______.

cytoplasm

The TCA (Krebs) cycle takes place in the mitochondria of eukaryote cells. Where does it take place in prokaryote cells?

cytoplasm

Where does the TCA cycle take place in bacteria?

cytoplasm

Consider the effect of temperature on enzyme activity. If the temperature is too high, proteins will ___ and no longer function. (ch6)

denature

Radio waves, X-rays, microwaves, UV light and gamma rays are all examples of ______. ch5

electromagnetic radiation

Glycolysis makes products that feed into

electron transport chain, TCA cycle/Krebs cycle AND fermentation.

The most highly resistant microbial structure is the bacterial ___. ch5

endospore

Hydrogen sulfide is produced as a result of certain types of anaerobic respiration. Some chemolithotrophs can then use this as a/an ______. (ch6)

energy source

In the case of plants, algae, and cyanobacteria, the two major products of photosynthesis are ______. (ch6)

glucose and oxygen

Lipid synthesis generally requires the ___ components and ___ acids. (ch6)

glycerol fatty

The primary pathway used by many organisms to convert glucose to pyruvate is ___ . (ch6)

glycolysis (AKA: Embden-Meyerhoff)

Chlorine and iodine are common disinfectants that belong to a class of chemicals called ___ . ch5

halogens

Chlorine and iodine are common disinfectants that belong to a class of chemicals called ___. ch5

halogens

Salting and drying decrease the availability of water in food, resulting in an environment that is ______ relative to microbes, thereby preventing their growth. ch5

hypertonic

Hydrogen peroxide is a more effective germicide on ______. ch5

inanimate objects

What is one disadvantage of using heat treatment to sterilize plastic items? ch5

items might melt

After glycolysis, pyruvate can be converted into ______ under anaerobic conditions.

lactic acid

Microorganisms that are free living are ______ to chemical disinfectants than microorganisms in a biofilm. ch5

less resistant

The reactions that capture radiant energy and convert it into chemical energy in the form of ATP are called the __ - __ reactions. (ch6)

light - dependent

A solution of sodium hypochlorite is more effective against bacteria at _______ pH. ch5

low

The sum total of all chemical reactions in a cell is called ___ . (ch6)

metabolism

The effectiveness of hydrogen peroxide as a germicide on living tissue like wounds is reduced because ______. ch5

our catalase enzymes quickly break it down

The TCA cycle completes the ______ of glucose. (ch6)

oxidation

The mechanism by which cellular respiration uses reducing power generated in glycolysis, the transition step, and the TCA cycle to synthesize ATP is ___ phosphorylation. (ch6)

oxidative

Cells obtain energy by ______ food molecules such as glucose.

oxidizing

Halogens are highly reactive _______ agents that _______. ch5

oxidizing; cause damage to proteins

Used as an alternative to chlorine for disinfecting water, ___ is a strong but unstable oxidizing agent that must be generated on-site, usually be passing air or O2 between two electrodes. ch5

ozone or O3

When selecting an appropriate chemical disinfectant, it is important to realize that the death rate is significantly influenced by ______. ch5

pH, temperature

The central metabolic pathway that generates reducing power in the form of NADPH is the ___ ___ pathway. (ch6)

pentose phosphate

What is the active ingredient in Lysol? ch5

phenolics

A high-solute environment damages microbial cells by causing ______. ch5

plasmolysis

What are the two main forms of energy? (ch6)

potential & kinetic

Energy is the ability to do work and can exist as ___ energy (stored energy) and ___ energy (energy of motion). (ch6)

potential, kinetic

When a cell processes glucose or other organic molecules through its central metabolic pathways, it does so to generate what three critical things? (ch6)

ATP, reducing power, precursor metabolites

Chemicals called ___ are used to prevent the growth of undesirable organisms in foods and beverages. ch5

preservatives or additives

When boiling or pasteurizing a sample, microorganisms are destroyed because their ______. ch5

proteins are irreversibly denatured

Which metal compound is used as a disinfectant in burn creams and bandage pads? ch5

silver

The main effect of low temperature storage is to ______. ch5

slow the activity of microbes

Which of the following binds to the active site of an enzyme?

substrate

As part of cellular respiration, a membrane-bound enzyme called ATP ___ uses energy from a proton-motive force to add a phosphate group to ADP. (ch6)

synthase

In the electron transport chain, protons are pumped across the cell membrane. This results in

the formation of a proton motive force.

Metabolism is best defined as ______. (ch6)

the sum total of all chemical reactions in a cell

In aerobic respiration, oxygen acts as

the terminal electron acceptor

Cells prefer to use carbohydrates as energy sources because

they are such good donors of hydrogen and electrons.

Certain intermediates of catabolic pathways, called precursor metabolites, are important because ______. (ch6)

they serve as carbon skeletons from which subunits of macromolecules can be made

This picture of a set of stairs best exemplifies the electron ___ ___ . (ch6)

transport chain (AKA: transport system)

What happens to the protons received from NADH in bacteria?

transported across the cytoplasmic membrane, setting up a proton motive force

What was the most likely mode of transmission of Cryptosporidium at the Seneca Lake State Park Sprayground? ch5Quiz

water-borne

Consider the use of low temperature storage for the preservation of food. Which of the following are accurate statements? ch5

-Refrigeration inhibits the growth of many pathogens and spoilage microorganisms by slowing or stopping critical enzyme reactions. -Psychrotrophic and some psychrophilic microorganisms can grow at refrigeration temperatures.

Some enzymes act with the assistance of a non-protein component. This component is called a ___ ; if that component is an organic molecule it can be called a ___. (ch6)

cofactor coenzyme

Identify each of the following by the most precise descriptive term as either a cofactor or coenzyme: magnesium: ___ ; NADP+: ___ ; zinc: ___ . (ch6)

cofactor coenzyme cofactor

True or false: Cells can replicate and transcribe DNA that contains thymine dimers. ch5Quiz

false

True or false: In prokaryotes and eukaryotes, the TCA cycle takes place in the mitochondria.

false

_______ does not actually destroy microbes or inhibit their growth but instead removes them physically from samples. ch5

filtration

_______ is a physical means used for destroying or removing microorganisms. ch5

filtration

Microorganisms that can grow on polysaccharides and disaccharides first break these down to glucose or precursor metabolites that can then enter into the pathway of ___ to be oxidized. (ch6)

glycolysis

From reading this case, you know that... ch5Quiz

hepatitis C is caused by a virus

Purines and pyrimidines are synthesized ______. (ch6)

in distinctly different manners

______ is the destruction of microbes by subjecting them to extremes of dry heat, reducing them to ashes. ch5

incineration

The Calvin cycle ______. (ch6)

incorporates carbon dioxide into organic compounds

Ozone ______. ch5

is a strong oxidizing agent

The series of sequential chemical reactions in a cell that converts a starting compound to an end product is called a ___ pathway. (ch6)

metabolic

The enzymes of the tricarboxylic acid cycle are found in the ___ matrix in eukaryotes and in the ___ in prokaryotes. (ch6)

mitochondrial cytoplasm

Phenolic compounds are effective against ______. ch5

most vegetative bacterial cells

After a deamination reaction removes the amino group from amino acids, the remaining carbon skeletons are converted into the appropriate ___ metabolites for entry into central metabolic pathways. (ch6)

precursor

In addition to yielding energy, catabolic pathways generate carbon intermediates that can be used in anabolic pathways for the biosynthesis of macromolecules. These carbon skeletons are called ___ ___ . (ch6)

precursor metabolites

The act of delaying spoilage is ______. ch5

preservation

Medical instruments are classified into three categories according to their risk for transmitting pathogens. These are: critical instruments, ___ instruments, and ___ instruments. ch5

semicritical, noncritical

______ destroy all microbes, including viruses and endospores. ch5

sterilants

True of false: Cryptosporidium was not susceptible to disinfection through filtration and chlorination of the spray park's water supply. ch5Quiz

true

UV irradiation inactivates Cryptosporidium because it... ch5Quiz

blocks the action of DNA polymerase

Early in glycolysis, two phosphates are added to the glucose molecule. These phosphates come from

breaking down ATP.

Silver is used as an antimicrobial in which of the following products? ch5

burn creams bandage pads

The process by which chemolithoautotrophs and photoautotrophs incorporate CO2 into organic compounds is called ___ ___ . (ch6)

carbon fixation

Enzymes are biological ______ that are typically _______. (ch6)

catalysts, protein

Adding sorbic, propionic, and benzoic acid to foods affects ______ of microbes. ch5

cell membrane function

True or false: The Calvin cycle is a two-step linear pathway that photosynthetic organisms use to fix carbon dioxide. (ch6)

false

True or false: There is a standard antimicrobial procedure available from the Centers for Disease Control and Prevention (CDC) that can be used for all different microorganisms under any condition. ch5

false

True or false: Choosing which germicide to use is not that complicated since we only consider how effective it is against the target microbes. ch5

false, it's a complicated decision

In terms of their metabolism, prokaryotes are _______ with respect to compounds they use for energy and _______ in their biosynthetic processes. (ch6)

highly diverse; remarkably similar

Cryptosporidium infection results in diarrhea that is self-limiting in healthy people, but in ______ patients, it can produce dehydration through severe diarrhea and can be life-threatening. ch5Quiz

infants & elderly

______ provides an alternative to heat for sterilization and disinfection, but the process damages some types of plastics. ch5

irradiation

High- ____ processing (HPP) is used to decrease the number of microbes in food while maintaining the color and flavor. ch5

pressure

The main purpose of cellular respiration is to

produce energy

Enzymes are usually ______.

protein

A common dry heat sterilization method used in the microbiology laboratory is ______. ch5

flaming the inoculating loop

The straining of a fluid or air through a membrane to trap microorganisms is known as ___ . ch5

filtration

Although generally less reliable than heat, germicidal chemicals are especially useful for treating ______. ch5

heat-sensitive items large surfaces

Disinfectants that destroy all viruses and vegetative organisms but not endospores are referred to as ____-level disinfectants. ch5

high

Metabolic pathways can be linear, ____ or ___ . (ch6)

branch, cycle

Which of the following are reasons an organism might use fermentation? (ch6)

- A suitable inorganic terminal electron acceptor is not available. - They lack an electron transport chain.

Match the term to its description to test your understanding of the use of moist heat to control microbial growth. ch5Quiz

- Commercial canning: Uses an autoclave called a retort to destroy the endospores of Clostridium botulinum. It will not destroy the endospores of some thermophiles. -Pasteurization: Heat applied to beverages to prevent spoilage and kill pathogens. High-temperature-short-time protocols include holding liquids at 72°C for 15 sec. Does not sterilize. -Steam under pressure: Requires use of an autoclave. To sterilize, temperature must reach 121°C for a minimum of 15 minutes.

Which of the following are true statements about what happens to glucose inside a cell? (ch6)

- Glucose can be used in catabolism to yield energy, or the precursor metabolites generated from its breakdown can be used in anabolism. - Some glucose might enter glycolysis, only to be siphoned off as a precursor metabolite for biosynthesis. - Some glucose might be oxidized to CO2, generating the maximum amount of ATP.

Oxidative phosphorylation, the mechanism by which cellular respiration uses the NADH and FADH2 generated in glycolysis, the transition step, and the TCA cycle to synthesize ATP, involves what two steps? (ch6)

- The electron transport chain generates a proton motive force. - ATP synthase uses the energy of the proton motive force to drive the synthesis of ATP.

Phenolics kill microorganisms by ______. ch5

-destroying cytoplasmic membranes -denaturing proteins

Germicidal chemicals ______. ch5

- usually react irreversibly with proteins, DNA, cytoplasmic membranes, or viral envelopes - are often poorly understood with regards to mechanisms of action

In a one D process, how many D values would it take to reduce a population of 10^10 cells to one survivor? ch5Quiz

10

For each glucose molecule that enters glycolysis, how many times does the TCA cycle "turn"?

2

How many ATP molecules are produced in the TCA cycle for each glucose molecule that enters glycolysis?

2

Hydrogen consists of

2 protons & 2 electrons

Proteins are composed of various combinations of usually how many different amino acids? (ch6)

20

How many molecules of NADH are generated for each turn of the TCA cycle?

3

If the theoretical maximum ATP yield in prokaryotes from oxidative phosphorylation is 34 ATP for a single glucose molecule, what is the total ATP gain when substrate-level phosphorylation is included? (ch6)

38 ATP

Excision repair, which is also used to correct thymine dimers, requires... ch5Quiz

CORRECT: None of the choices are correct. heat acid light RNA

Match up each type of enzyme inhibition with its characteristic. (ch6)

Competitive inhibition = Inhibitor binds to the active site of the enzyme, blocking access of the substrate Non-competitive inhibition by regulatory molecules drop zone empty = Inhibitor reversibly changes the shape of the enzyme so that the substrate can no longer bind to the active site Non-competitive inhibition by enzyme poisons = Inhibitor permanently changes the shape of the enzyme, making the enzyme non-functional

Categorize the given medical instruments as critical, semi-critical or non-critical. ch5Quiz

Critical: - Scalpel - Venous catheter - Needle Semicritical: - Thermometer - Endotracheal tube - Gastrointestinal endoscope Noncritical: - Blood pressure cuff - Stethoscope

What organism was the cause of the outbreak at the Seneca Lake Sprayground? ch5Quiz

Cryptosporidium

Which of the following contain a metal ion that can accept and donate electrons?

Cytochromes

What enzyme(s) is/ are involved in replacing the removed nucleotides following excision repair? ch5Quiz

DNA polymerase, followed by DNA ligase

In addition to glucose, which of the following organic compounds can serve as energy sources for microbes? (ch6)

Disaccharides, polysaccharides, lipids, fatty acids, monosaccharides, proteins

All of the following accurately describe enzymes EXCEPT ______. (ch6)

EXCEPT: enzymes provide energy to help reactions proceed more rapidly. - enzymes are very specific, usually acting on only one or a few substrates - the name of an enzyme typically reflects its function and ends in -ase - enzymes are biological catalysts - enzymes are not used up in the process of catalyzing reactions

All of the following are characteristics of bleach, a solution of sodium hypochlorite, EXCEPT ______? ch5

EXCEPT: it is only effective against a limited range of microorganisms -it reacts with some organic compounds to form carcinogens -it is irritating to skin and mucous membranes -its germicidal activity is disrupted by organic compounds -it is corrosive and toxic -it reacts with some organic compounds to form trihalomethanes

All of the following are examples of electromagnetic radiation EXCEPT ______. ch5

EXCEPT: sound waves - visible light - mass of an electron - gamma rays - x-rays

Chlorine-releasing compounds such as sodium hypochlorite (bleach is a 5.25% solution) are used for all of the following EXCEPT ______. ch5

EXCEPT: wound treatment and skin cleansing (because sodium hypochlorite is too irritating to skin and mucous membranes) -food equipment sanitation -sewage and waste water disinfection -household cleaning -swimming pool treatments

Where do NADH and FADH2 go after being produced in the TCA cycle?

Electron transport chain

___ oxide is an extremely useful gaseous sterilizing agent that destroys all microbes and is often used to sterilize fabric, equipment, and implantable devices. ch5

Ethylene

Match the descriptions and antimicrobial agents to the appropriate type of germicide to test your knowledge of alcohols, halogens, phenolic compounds, and quaternary ammonium compounds as germicidal chemicals. ch5Quiz

Halogens: - Chlorine, chlorine dioxide, iodine - Common disinfectant which oxidizes proteins and other cell components Quaternary ammonium compounds: - Cationic detergent which can be safely used on food preparation surfaces - Compounds reacts with membranes to destroy many vegetative bacteria and enveloped viruses - These compounds are ineffective against mycobacteria, naked viruses, and Pseudomonas species Alcohols: - Ethanol or isopropanol - Aqueous solutions which can kill vegetative bacteria and fungi, but not endospores or naked viruses - Solutions can be used as antiseptics or to disinfect instruments without leaving a residue Phenolic compounds: - Carbolic acid - Germicidal agent which can leave an antimicrobial residue after use

Autotrophs use carbon dioxide (CO2) to synthesize organic compounds. Which of the following descriptions of this process are true? (ch6)

In photosynthetic organisms, the process is called the light-independent reactions. It often involves the Calvin cycle. It is called carbon fixation.

Which of the following are physical ways to remove or destroy microbes? ch5

Incineration Ultraviolet radiation Filtration Autoclaving

What is the active site of an enzyme? (ch6)

The critical site to which a substrate binds by weak forces.

The light-independent reactions of photosynthesis occur _______ the light-dependent reactions, and function to _______. (ch6)

after; synthesize organic compounds from CO2

Fats are hydrolyzed by lipases. The glycerol component is then converted to a precursor metabolite, and the fatty acids are degraded using a series of reactions called β-oxidation that remove successive 2-carbon units. Where do these components enter the central metabolic pathways for further oxidation? (ch6)

The precursor metabolites from glycerol enter glycolysis; the 2-carbon units from fatty acids are added to coenzyme A and enter the TCA cycle.

Microorganisms can grow on a variety of organic compounds other than glucose, including polysaccharides, proteins, and lipids. How do they accomplish this? (ch6)

They break these macromolecules down into appropriate precursor metabolites that are then introduced into central metabolism or used in biosynthesis.

True or false: Chlorine treatment is effective in removing Cryptosporidium from water. ch5Quiz

True

For each six-carbon molecule of glucose that enters glycolysis, how many molecules of pyruvate are made, and how many carbon atoms does each pyruvate have? (ch6)

Two molecules of pyruvate, each with three carbon atoms.

What type of radiation in sunlight causes damage to DNA? ch5Quiz

UV radiation Alpha radiation Gamma radiation IR radiation Beta radiation

The critical site of an enzyme to which a substrate binds by weak forces is called the ___ ___ . (ch6)

active site

The critical site of an enzyme to which a substrate binds by weak forces is called the ____ ___ . (ch6)

active site

The energy released during the reactions of glycolysis is used to form ______.

adenosine triphosphate (aka: ATP)

Aldehydes typically kill microbes by ______. ch5

altering nucleic acids altering proteins

Proteins are hydrolyzed by proteases, enzymes that break the peptide bonds between ___ ___ subunits. (ch6)

amino acid

As bacteria grow in broth, oxygen becomes depleted. At that point, most bacteria switch to fermentation to continue growing. In tetrathionate broth however, S. enterica can switch to anaerobic respiration. This gives the organism a growth advantage because

anaerobic respiration yields more ATP per glucose molecule than fermentation.

During glycolysis, a single 6-carbon molecule of glucose is converted to two 3-carbon pyruvate molecules. During the later steps in this process, how many molecules of ATP are generated?

4

For each glucose molecule broken down by glycolysis, how many net ATP molecules are produced?

4

Aqueous solutions of alcohol at a concentration of ______ are more effective than 100% alcohol. ch5

60-80%

Consider the theoretical maximum ATP yield from the complete oxidation of glucose via aerobic respiration in prokaryotes. Match the relative contribution in terms of ATP (substrate-level phosphorylation plus oxidative phosphorylation) with the correct metabolic component. (ch6)

8 ATP = Glycolysis 6 ATP = Transition step 24 ATP = TCA Cycle 38 ATP = Total yield of aerobic respiration

During the electron transport chain, ATP will be made from

ADP + Pi

With respect to their synthesis, how are amino acids typically grouped? (ch6)

By structurally related families that share common biosynthesis pathways

Match the type of enzyme inhibition on the left with the example of an inhibitor on the right. (ch6)

Competitive inhibition = sulfa drugs Non-competitive inhibition by regulatory molecules = allosteric regulators Non-competitive inhibition by enzyme poisons = mercury

In order to form lipids, how are fatty acids and glycerol synthesized? (ch6)

Fatty acid chains are assembled from 2-carbon acetyl groups from the transition step; the precursor to glycerol comes from glycolysis.

Match each type of radiation with its description. ch5Quiz

Ionizing radiation: High energy radiation that directly destroys DNA and damages cytoplasmic membranes. It can also cause indirect damage by producing reactive oxygen species (ROS). Ultraviolet radiation: Not very penetrating radiation. Easily stopped by interfering materials. Works by producing thymine dimers in DNA strands. Most effective at close range and with long duration of exposure. Microwaves: Doesn't affect microorganisms directly, but can generate heat in fluids which can indirectly kill microbes.

In respiring bacteria, how does ATP synthase generate ATP? (ch6)

It uses the energy released from allowing protons to flow back into the cell to add a phosphate group to ADP.

Which of the following combinations of molecules is produced during the light-dependent reactions of photosynthesis and used in the light-independent reactions? (ch6)

NADPH and ATP

Which of the following would be an example of occupational exposure for a healthcare worker? ch5Quiz

Needle stick. Cut with sharp object such as scalpel. Contact of mucous membranes with blood.

Classify the given microbes and infectious agents into "sensitive" or "resistant" with regards to effect of antimicrobial procedures. ch5Quiz

Sensitive: -Escherichia species -bacillus vegetative cells -HIV (enveloped) Resistant: -Pseudomonas species -Giardia cysts -prion -bacillus endosperes -poliovirus -mycobacteria species

Which of the following statements accurately describe biochemical pathways? Choose all that apply.

They convert an initial substrate through a series of steps into an end product. They are well-organized and structured. They can be linear, branched, or cyclical. They are carefully regulated.

Although the actual procedure is much more involved, the basic metabolism of wine-making involves inoculating grape juice with a special strain of the yeast Saccharomyces cerevisiae. S. cerevisiae will preferentially perform aerobic respiration on sugars in the juice but can also ferment those sugars to yield CO2 and alcohol, an important component of wine. Assume you inoculate a completely full container of juice and then close the lid. What will the yeast do? (ch6)

They will grow aerobically, consume the O2 dissolved in the juice, and then switch to fermenting sugars to yield alcohol.

It is often difficult to choose which germicide to use because often the most effective options ______. ch5

are not the safest

Nucleotide subunits of DNA and RNA are composed of three units: a 5-carbon sugar, a phosphate group, and a nucleobase. They are initially synthesized ______. (ch6)

as ribonucleotides that can be converted to deoxyribonucleotides by replacing the 2' hydroxyl group with a hydrogen atom

UV water treatment systems are effective in treating... ch5Quiz

bacteria, viruses and protozoans.

Although the pentose phosphate pathway is used by cells to break down glucose, it is particularly important because of its contribution to ______. (ch6)

biosynthesis

In photosynthesis, what do the light reactions, or light-dependent reactions, accomplish? (ch6)

They capture radiant energy and convert it to chemical energy in the form of ATP.

Glucose catabolism encompasses two key processes: (1) oxidizing glucose molecules to generate ATP, reducing power, and precursor metabolites; and (2) transferring the electrons carried by NADH and FADH2 to the terminal electron acceptor. The second process, transfer of electrons, is accomplished as part of which of the following? (ch6)

fermentation cellular respiration

Phenolics are ______. ch5

germicidal

Starch and cellulose are both polymers of ______ , which means that, following hydrolysis, the component monosaccharides can enter directly into the central metabolic pathway of ______ to be oxidized. (ch6)

glucose glycolysis

Glycolysis is the central metabolic pathway that involves the breakdown of ______.

glucose (AKA: sugar)

Fats, the most common simple lipids, are broken down by lipases into their component ______. (ch6)

glycerol and fatty acids

Which of the following use moist heat to destroy microbes? ch5

Pasteurization Pressurized steam Boiling

Ethylene oxide is gaseous agent that ______. ch5

is very useful for sterilizing heat- or moisture-sensitive items

Adding preservatives such as benzoic acid to food is important because ______. ch5

it inhibits growth of many bacteria and mold