micro test 1
21. What is the chemical formula of glucose? A. C6H12O6 B. C5H10O5 C. C4H8O5 D. C6H6O12 E. C12H6O6
A
An atom that has donated an electron to form an ionic bond is classified as _____ and is positively charged. A. A cation B. Polar C. Nonpolar D. A solvent E. An anion
A
Chemical bonding between two different atoms always occurs between their A. Unfilled outer orbital B. Nuclei C. First shells D. Cores E. Third shells
A
A triglyceride contains fatty acids that are _____ and therefore do not dissolve with water. A. Hydrophilic B. Carbohydrates C. No lipid groups D. Ribose sugars E. Hydrophobic
E
Cations are different from anions because cations A. Have a positive charge B. Are formed by the loss of an electron C. Are attracted to negatively charged ions D. Include Na+, Li+, Mg2+, Al3+ E. All of the choices
E
Enzyme reactions are affected by A. Temperature B. Enzyme concentration C. Concentration of substrate D. pH E. All of the choices
E
Fatty acids are removed from triacylglycerols by the chemical process of A. Dehydration B. Hydration C. Solvation D. Polarity E. Hydrolysis
E
The part of a biological molecule that participates in chemical reactions is referred to as A. ATP B. A covalent bond C. Primary structure D. An active site E. functional group
E
Water surrounds cations and anions and keeps them dissociated in solution by forming A. Nonpolar covalent bonds B. Tertiary structure C. Peptide bonds D. Active sites E. Spheres of hydration
E
What is the name of a reaction that results from oxidation of one reactant coupled to the reduction of another? A. Reciprocal B. A chemoheterotrophic reaction C. Aerobic respiration D. Competitive inhibition E. Redox
E
Which is an example of a phosphorylation reaction? A. Amino acids to protein B. DPN to DPNH C. DPNH to DPN D. Glycogen to glucose E. Glucose to phosphoglucose
E
Which of the following is not a characteristic of glycolysis? A. Anaerobic metabolism B. Substrate-level phosphorylation C. Net production of 2 ATP D. Glucose is oxidized to 2 pyruvate molecules E. Takes place on microbial cell membranes or on the inner membrane of the mitochondrion
E
Which of the following is not synthesized by cells? A. Carbohydrates B. Nucleic acids C. Proteins D. Lipids E. Nalco
E
_____ bonds form when electrons are transferred between atoms, whereas _____ bonds involve the sharing of electrons. A. Covalent; hydrogen B. Hydrogen; covalent C. Ionic; hydrogen D. Covalent; ionic E. Ionic; covalent
E
_____ can be inorganic, whereas _____ is always organic. A. An enzyme; an allosteric inhibitor B. A substrate; a product C. FAD; NAD+ D. An oxidation reaction; a reduction reaction E. A cofactor; a coenzyme
E
an example of how a pathogen is transmitted to a new host is via A. Air B. Food C. Water D. Insects E. All of the choices
E
13. If a person is immunocompromised, it is very likely that he or she may be A. A carrier B. An AIDS patient C. Disease-resistant D. Lacking sugar E. Lacking minerals
B
Animals store carbohydrates in the form of A. Monosaccharide's B. Glycogen C. Starch D. Disaccharides E. Cellulose
B
Carbon dioxide (CO2) forms as a result of A. Ionic bonds forming between carbon and oxygen B. Two pairs of electrons from the carbon forming double covalent bonds with each oxygen C. Single covalent bonds between carbon and oxygen D. Hydrogen bonding between carbon and oxygen
B
Helices and pleated sheets that contribute to protein structure are considered to be which level of protein structure? A. Primary B. Secondary C. Tertiary D. Quaternary
B
The biosynthesis of glycogen, using glucose, is an example of A. Aerobic respiration B. Anabolism C. Glycolysis D. The Krebs cycle E. Proton motive force
B
The chemical process that takes place inside every cell and is responsible for the release of energy is referred to as A. Competitive inhibition B. Catabolism C. Feedback inhibition D. Allosteric inhibition E. Anabolism
B
What always occurs during catabolism? A. Aerobic respiration B. Electron rearrangement C. Feedback inhibition D. Proton motive force E. Competitive inhibition
B
What is common to all monoglycerides, diglycerides, and triacylglycerol (fats)? A. Three fatty acids B. Glycerol C. An amino acid D. A monosaccharide E. A nitrogenous base
B
Which is an example of a reduction reaction? A. Amino acids to protein B. DPN to DPNH C. DPNH to DPN D. Glycogen to glucose E. Glucose to phosphoglucose
B
Which of the following is a steroid found in animal cell membranes? A. Glycolipid B. Cholesterol C. Nucleic acid D. Amino acid E. Protein
B
the overarching term that decribes the study of the factors responsible for the prevalence and transmission of infectious disease is A. Pathogenesis B. Epidemiology C. Immunology D. Virology
B
which substance or process decreases the virulence of a bacterial pathogen in a host A. Peptidoglycan B. Adaptive immune cells C. Virulence factor D. Binary fission E. Toxins
B
All 20 amino acids have three common chemical components attached to a central carbon. Which of the following is not attached? A. Hydrogen B. Carboxyl group C. Glucose D. Amino group
C
All of the following are components of a nucleotide except A. Nitrogenous base B. Phosphate group C. Amino acid D. Pentose sugar
C
Carbon atoms can form how many bonds with other atoms? A. 6 B. 12 C. 4 D. 2 E. 8
C
In a chemical reaction pyruvate has gained one electron. It has therefore been A. Catabolized B. Hydrolysed C. Reduced D. Phosphorylated E. Oxidized
C
Microorganisms possessing metabolic pathways that can function in the presence or absence of oxygen are described as A. Obligate anaerobes B. Anabolic respirers C. Facultative anaerobes D. Catabolic anaerobes E. None of the above
C
Some proteins form _____ which stabilizes their folding. A. Spheres of hydration B. Double bonds C. Disulfide bridges D. Magnetic resonance E. Energy of activation
C
What happens when one molecule of glucose is oxidized completely using the Krebs cycle and the electron transport chain? A. 12 H2O molecules are formed B. anaerobic respiration occurs C. 38 ATP molecules are formed D. 3 CO2 molecules are formed E. 12 O2 molecules are consumed
C
What has occurred when a large molecule is broken down into small molecules? A. Anabolism B. Anaerobic respiration C. Catabolism D. Feedback inhibition
C
When an enzyme has bound to its substrate a(n) _____ is formed. A. Proteolytic complex B. Cofactor complex C. Enzyme-substrate complex D. Coenzyme complex E. Carrier complex
C
Which is an example of an oxidation reaction? A. Amino acids to protein B. DPN to DPNH C. DPNH to DPN D. Glycogen to glucose E. Glucose to phosphoglucose
C
Which is not true of covalent bonds? A. They can be polar B. They can be nonpolar C. They can be composed of cations and anions D. They occur when electrons are shared between atoms E. Most molecules synthesized in cells are covalently bonded
C
Which of the following is part of a glycolipid? A. Adenine B. Amino acid C. Carbohydrate D. Phosphate E. ATP
C
which of the following is true of enterhemorrhagic bacteria contracted from growund beef
It may be the result of ingesting Escherichia coli 0157:H7
a term reserved for a disease that is acquired in a clinical setting is known as
Nosocomial
In the context of structure and function, explain why lowering the pH of a solution would inhibit an enzyme's activity.
The vast majority of enzymes are proteins made up of amino acids held together by peptide bonds. The weak bonds that stabilize secondary, tertiary, and quaternary structure that are responsible for the three-dimensional structure of enzymes are destabilized by alterations in pH, causing denaturation. If an enzyme becomes denatured its active site may adopt a different conformation that will no longer be able to bind to reactants. Therefore, changing the structure of an enzyme disrupts its function.
microoganisms that normally colonize skin and mucous membranes can be
commensal nonpathogenic mutalistic protective against pathogens
Chlorine has at atomic number of 17. Therefore, which of the following is not correct regarding chlorine? A. Chlorine has a mass number of 34 B. Chlorine has 2 electrons in the first shell, 8 electrons in the second shell, and 7 electrons in the third shell C. If chlorine accepts an electron, it becomes a chloride cation D. Chlorine needs only one electron to fill its outer shell E. Atomic chlorine has 17 electrons
A
DNA differs from RNA in that A. DNA uses the sugar deoxyribose, whereas RNA uses the sugar ribose B. Only DNA has 5-prime to 3-prime direction C. DNA uses uracil, whereas RNA uses thymine D. DNA is usually found as a single chain, whereas RNA is usually found as a double helix
A
In a mitochondrion carrying out electron transport, the proton concentration gradient develops A. Across the inner mitochondrial membrane B. In the cytosol C. In the nucleus D. In the space between the outer membrane and the plasma membrane E. Across the outer mitochondrial membrane
A
In feedback inhibition which reaction in the following pathway would the final product inhibit? W →X → Y → Z A. W → X B. X → Y C. Y → Z D. Y E. Z
A
Negative feedback inhibition works by A. The product of a metabolic pathway inhibiting a key enzyme early in the synthesis of the product B. Altering pH and denaturing the enzyme C. Binding to the binding site of an enzyme and interfering with substrate binding D. Increasing the energy of activation of a chemical reaction E. Increasing the free energy of the reaction
A
Temperature, pain, redness, and swelling are the hallmarks of A. Inflammation B. Virulence C. Nosocomial infections D. Immunological memory E. None of the above
A
The components of ATP include A. Adenine, ribose sugar, and three phosphates B. Amino acid and three phosphates C. Adenine, triglycerols, and one phosphate D. Adenine, deoxyribose sugar, and three phosphates
A
The purines of nucleic acids are A. Adenine and guanine B. Thymine and guanine C. Adenine and cytosine D. Thymine and cytosine E. Uracil and guanine
A
The term antiparallel means that DNA A. Has two strands that run in opposite directions B. Has secondary structure in both strands C. Has one strand containing deoxyribose sugars and the other containing ribose sugars D. Can bind to RNA by using complementary base pairs E. Contains purines, whereas RNA contains pyrimidines
A
When two monosaccharides are joined together, _____ is formed through _____ synthesis. A. A disaccharide; dehydration B. A polysaccharide; hydrolysis C. Glycogen; dehydration D. A disaccharide; hydrolysis E. Starch; dehydration
A
Which is an example of a dehydration reaction? A. Amino acids to protein B. DPN to DPNH C. DPNH to DPN D. Glycogen to glucose E. Glucose to phosphoglucose
A
Which of the following is a mismatched pair? A. Heterotrophs — CO2 B. Chemo heterotrophs — organic compounds C. Chemoautotrophs — inorganic molecules D. Photoautotrophs — sunlight and CO2 E. Infectious organisms — organic compounds
A
Which of the following refers to the loss of protein three dimensional structure when temperature or pH is altered? A. Denaturation B. Polarity C. Hydration D. Hydrolysis E. Dehydration
A
Describe three ways in which the cell can regulate enzyme activity.
Cells can regulate enzyme activity by competitive, allosteric, and feedback inhibition. Competitive inhibition operates when an inhibitory molecule, bearing structural similarity to the substrate, binds to the enzyme's active site and thereby interferes with the substrate's ability to bind. Allosteric inhibition also involves an inhibitory molecule, but it binds to a site other than the active site or the enzyme. Once bound, the enzyme's shape changes affecting the three-dimensional contour of the active site, which can then no longer bind to the substrate. Feedback inhibition is similar to allosteric inhibition except that the inhibitor is the product of the metabolic pathway itself. As the product of the pathway accumulates, it binds to the first enzyme in the pathway, causing it to change shape, resulting in the inactivation of the entire pathway.
The appearance of insect-borne diseases in more northerly climates can be attributed to what aspects of climate change? Which diseases are of most concern?
Climatic factors which affect infectious disease include temperature, humidity and CO2 concentration and increases in these factors have occurred over the last 10 years with an increase in the incidence of insect-carried diseases. Insect-borne diseases, such as malaria, are of particular concern as climate related changes in insect vector habitat ranges brings such diseases into new areas where the human population has no experience of these diseases, resulting in these becoming emerging diseases in these areas. Increased temperature and humidity allows insects to breed more easily and survive winters in northern climates, and this leads to larger populations of these insects in more frequent contact with humans. Along with the expansion of insect habitat have come epidemics of West Nile virus, dengue virus and bunyavirus.
. The quaternary structure of a protein refers to A. Its amino acid sequence B. The way the protein folds C. The links that stabilize the protein D. The way protein subunits interact with each other E. All of the above
D
1. Which of the following indicates the correct order of the items from simple to complex? A. molecules > atoms > cells > tissues B. Tissues > cells > molecules > atoms C. Cells > molecules > atoms > tissues D. Atoms > molecules > cells > tissues E. Atoms > molecules > tissues > cells
D
2. Atomic structure gives an atom A. Its mass B. Its reactivity C. Its valence in molecules D. All of the above
D
6.When a molecule only contains sets of 2 shared electrons, it must contain which bonds? A. Hydrogen B. Inorganic C. Ionic D. Covalent
D
An allosteric inhibitor is added to an enzyme substrate mixture. What is likely to happen? A. The product of the reaction will increase B. The enzyme will denature C. The inhibitor will bind the active site of an enzyme and interfere with substrate binding D. The inhibitor will bind to a site other than the active site and cause a conformational change of the enzyme
D
Investigate the periodic table. What is the common theme of the elements in Column 2? A. They can all become readily accept electrons B. The ions they form will be negative C. The ions they form will have a single charge D. The ions they form will have a double charge
D
The building blocks of _____ are _____. A. Polysaccharides; fatty acids B. DNA; ribose C. Steroids; glucose D. Proteins; amino acids E. Glycogen; starch
D
The location where a substrate fits into an enzyme is known as the A. Cofactor site B. Plebi site C. Polar site D. Active site E. Carrier site
D
The mechanism of competitive inhibition involves A. Inhibiting the first enzyme in a metabolic pathway B. Decreasing the pH and denaturing the enzyme C. Increasing the energy of activation of a chemical reaction D. Binding to an enzyme at the active site E. Binding to a site distant from the active site and causing a conformational change of the enzyme
D
Unlike most pathogens, photoautotrophs A. Are parasitic B. Can use organic chemicals for energy C. Can use organic chemicals as a carbon source D. Can survive and grow on CO2 and sunlight E. None of the choices
D
What is the result if an enzyme is subjected to extremely high temperatures? A. The enzyme's rate of reaction will increase B. There will be an alteration in electrical charges, which will interfere with substrate interaction C. The substrate concentration will be too low for enzyme activity D. The hydrogen bonds stabilizing the three-dimensional structure will break and the enzyme will become denatured
D
Which is an example of a hydrolysis reaction? A. Amino acids to protein B. DPN to DPNH C. DPNH to DPN D. Glycogen to glucose E. Glucose to phosphoglucose Answer: D
D
Which of the following distinguishes an enzyme from an apoenzyme? An apoenzyme_____. A. Is the mirror image of its enzyme? B. Cannot bind a competitive inhibitor C. Cannot form an enzyme-substrate complex D. Contains no cofactor
D
Which of the following molecules is not a lipid? A. Cholesterol B. Glycolipid C. Steroid D. Glycogen E. Phospholipid
D
Which of the following statements is correct? A. A base is a H+ ion donor B. Pure water is completely neutral and has a pH of 0 C. On a pH scale, gastric fluids are classified as alkaline D. H+ ion concentration is inversely related to pH E. If the hydroxyl ions outnumber the H+ ions, the pH will be less than 7.0
D
Which of the following statements regarding NAD+ is incorrect? A. NAD+ is a vitamin B. NAD+ is a coenzyme C. NAD+ enters the electron transport chain as NADH D. In its reduced form NADH becomes NAD+ E. More NADH is formed more often than FADH2 in the Krebs cycle
D
In terms of chemical structure discuss the similarities and differences between DNA and RNA.
DNA and RNA are both nucleic acids composed of polymers of nucleotides held together by covalent phosphodiester bonds found on the sugar phosphate backbone. In both cases, the nucleotides contain a phosphate group, a pentose sugar, and a nitrogenous base, which can be either a purine or a pyrimidine. DNA and RNA both exhibit polarity, with a distinct 5' terminal (the phosphate end) and a 3' terminal (the pentose sugar end). DNA and RNA use the purines adenine and guanine. DNA and RNA differ in that DNA has a deoxyribose sugar, whereas RNA has a ribose sugar. They use different pyrimidines with DNA using cytosine and thymine, and RNA using cytosine and uracil. DNA is usually a double-stranded antiparallel molecule stabilized by hydrogen bonding between adenine and thymine, and also between guanine and cytosine. In contrast, RNA is most often found as a single-stranded molecule.
Name and describe the four levels of protein structure and the chemical bonds involved at each level. Why is protein structure important?
Protein structure has four levels: primary, secondary, tertiary, and quaternary. Primary structure is simply the linear sequence of amino acids held together by peptide bonds. Secondary structure uses hydrogen bonds on the backbone of the polypeptide to form folds (pleated sheets) and coils (helices). Tertiary structure uses hydrogen bonds, disulfide bonds, and other weak bonds between R groups to provide folding of the chain upon itself, creating major three-dimensional structure. Quaternary structure is used only by proteins that are composed of more than one polypeptide chain and also involves hydrogen bonds and disulfide bonds as seen with tertiary structure. Protein structure is important as determines protein functionality. If a protein does not fold correctly or becomes denatured, the functionality of the protein is lost.
In early June of 2013, people in the Middle East were worried about a new coronavirus which at that time had led to about 50 confirmed cases, 30 of whom had died. The virus could spread from patient to patient in hospitals and soon patients arriving from the Middle East were spreading it to Europe. Give your best guess as to the means by which the virus is transmitted.
The coronavirus in this case was Middle East Respiratory Syndrome Coronavirus (MERS-Cov). Some transmission possibilities include hand-to-hand contact, droplets in coughs and sneezes, close contact such as kissing, and through inanimate objects like door knobs and toys.
A rapid rise has recently occurred in the number of tuberculosis patients and in the problems of treating this disease. What factors are contributing to this
The main problems are the increased use of injected illegal drugs, which allows the disease to spread via needles, and the increased incidence of AIDS, which destroys the immune protection against tuberculosis. Poor socioeconomic conditions and migration also play a role.
Provide two examples of biological molecules made by anabolism that would be required for the replication of bacteria to occur, identifying the reactants and products.
Two, among many, examples of large molecules that need to be synthesized during the replication of bacteria include nucleic acids and phospholipids. Every time a cell divides, its genetic material must be duplicated. The reactants include pyrimidines, purines, deoxyribose sugar, and phosphates. The product is DNA. As the cell prepares for division it needs to increase the amount of plasma membrane to surround the two cells arising from the original cell. The reactants include fatty acids, glycerol, and phosphate-containing groups. The product is phospholipid.
Explain why anabolism is important during the replication of bacteria during an infection.
When bacteria replicate, anabolism is required to ensure that a continuous supply of large molecules is provided for the new cells generated. Anabolism is the process of biosynthesis, and it requires energy from the cell to build large molecules from small building blocks.
which of the following explains the dramatic decrease in death rates attributed to infectious disease during the twentieth century
advances in public health chlorination of drinking water use of antibiotics effective vaccine programs
During alcoholic fermentation the intermediate _____ is synthesized from pyruvic acid. A. NAD+ B. Acetaldehyde C. Lactic acid D. ATP E. Acetyl CoA
b
Which of the following is a common feature of most fermentation pathways? A. The production of glucose B. The formation of lactic acid C. The provision of electrons by NADH D. The use of the Krebs cycle E. The conversion of pyruvate to acetyl CoA
b
Which of the following is not a characteristic of the Krebs cycle? A. Aerobic metabolism B. Conversion of pyruvate to acetaldehyde C. Transfer of electrons to NAD+ and FAD D. Oxidation of acetyl-coA to CO2 E. Net production of 1 ATP per one turn of the cycle
b
Which of the following statements regarding enzymes is false? A. Enzymes increase the rate of a chemical reaction B. The amount of energy required or released when a substrate is converted to a product is known as the allosteric energy C. Enzymes lower the energy of activation D. Enzymes are not changed by the reactions in which they participate E.A chemical reaction will occur only if there is sufficient activation energy to initiate the
b
Which of the following statements regarding eukaryotic electron transport is true? A. Electron transport occurs in the cytoplasm B. A consequence of electron transport is the formation of a concentration gradient of protons C. Generates a concentration gradient of electrons D. NADH and FADH2 are reduced during electron transport
b
the most common means by which multi-drug resistant tuberculosis is transmitted is
by dispersal of aerosols containing droplets carrying causative bacteria
3. Which of the following statements is not true? A. Oxygen has 2 unpaired electrons in the second shell. B. Nitrogen has 7 electrons which occupy the first and second shells. C. Hydrogen has an atomic number of 1 and an atomic weight of 2. D. Carbon has an atomic number of 6 and an atomic weight of 12. E. The third shell must contain 18 electrons to be stable.
c
What is the general term for the first obstacles to infection which can prevent the pathogenic organism from doing harm? A. Nosocomial response B. Virulence factor C. Host defense D. Toxins E. Digestive enzyme
c
Which of the following is required to fuel anabolic reactions in cells? A. Triglycerols B. Proteins C. ATP D. Carbohydrates E. Nucleic acids
c
which of the following is a mismatched pair A. Bacillus anthracis — respiratory disease B. Escherichia coli — bloody diarrhea C. Mycobacterium tuberculosis — food poisoning D. Avian influenza — human flu E. Yersinia pestis — plague
c
a blank is the general term that describes someone who does not become sick when harboring an infectious pathogen, but has the potential to transmit the infectious pathogen to others
carrier
True or False? Enzymes catalyze reactions because they increase the difference in energy between the substrate and the products.
false
True or False? Enzymes catalyze reactions when they increase the energy of activation of the reaction.
false
True or False? When a molecule is oxidized it receives electrons.
false
True or False? Cellular respiration can be anaerobic.
true
True or False? Nearly all infectious organisms are chemoheterotrophs.
true
True or False? The regulation of enzymes is illustrated by the ability of the end product of a series of enzymatic reactions to inhibit the first enzyme in the pathway.
true
the general term for the ability of an organism to overcome host defenses and cause disease is associated with the blank of a pathogen
virulence
