Archive for June 2020

How is ATP produced during non-cyclic photophosphorylation?

13:40 Add Comment

How is ATP produced during non-cyclic photophosphorylation?



A. Substrate-level phosphorylation
B. Oxidative phosphorylation
C. Photophosphorylation
D. Both substrate-level phosphorylation and photophosphorylation
E. Both substrate-level phosphorylation and oxidative phosphorylation


Answer: C. Photophosphorylation

What is the general function of NADH?

13:37 1 Comment

What is the general function of NADH?



A. To generate ATP.
B. To transport protons across the membrane.
C. To transport electrons to the ETC.
D. To phosphorylate glucose.
E. To reduce oxygen.


Answer: C. To transport electrons to the ETC.

How is ATP produced during aerobic respiration?

13:37 Add Comment

How is ATP produced during aerobic respiration?



A. Substrate-level phosphorylation
B. Oxidative phosphorylation
C. photophosphorylation
D. Both substrate-level phosphorylation and photophosphorylation.
E. Both substrate-level phosphorylation and oxidative phosphorylation.


Answer: E. Both substrate-level phosphorylation and oxidative phosphorylation.

If an enzyme is a holoenzyme, you know that ___________.

13:37 Add Comment

If an enzyme is a holoenzyme, you know that ___________.



A. It can work in acidic conditions
B. A cofactor is present.
C. It consists entirely of amino acids.
D. It can catalyze one or more different types of reactions.


Answer: B. A cofactor is present.

According to the chemiosmotic mechanism, ATP is generated when ____.

13:36 Add Comment

According to the chemiosmotic mechanism, ATP is generated when ____.



A. A high-energy phosphate group is transferred from an intermediate metabolite to ADP.
B. Electrons are transferred between carrier molecules.
C. Protons are moved across a membrane.
D. Chlorophyll liberates an electron.
E. Glucose is oxidized.


Answer: C. Protons are moved across a membrane.

Which of the following is the best definition of oxidative phosphorylation?

13:36 Add Comment

Which of the following is the best definition of oxidative phosphorylation?



A. The energy released in the oxidation of electron carrier molecules is used to generate ATP via a gradient.
B. The direct transfer of a phosphate group to ADP.
C. Energy from electrons is used to oxidize glucose.
D. Generation of ATP with the use of oxygen.


Answer: A. The energy released in the oxidation of electron carrier molecules is used to generate ATP via a gradient.

Which of the following is the best definition of fermentation?

13:36 Add Comment

Which of the following is the best definition of fermentation?



A. The production of ethyl alcohol from glucose.
B. The oxidation of glucose with organic molecules serving as electron acceptors.
C. The reduction of glucose to pyruvic acid.
D. The complete catabolism of glucose to carbon dioxide and water.


Answer: B. The oxidation of glucose with organic molecules serving as electron acceptors.

Non-competitive inhibition occurs when _____.

13:36 Add Comment

Non-competitive inhibition occurs when _____.



A. The inhibitor binds to the active site of the enzyme.
B. The inhibitor binds to the allosteric site of the enzyme.
C. The inhibitor destroys the enzyme.
D. The inhibitor is acted upon by the enzyme.


Answer: B. The inhibitor binds to the allosteric site of the enzyme.

Competitive inhibition occurs when _____.

13:35 Add Comment

Competitive inhibition occurs when _____.



A. The inhibitor binds to the active site of the enzyme.
B. The inhibitor binds to the allosteric site of the enzyme.
C. The inhibitor changes the shape of the enzyme.
D. The inhibitor is acted upon by the enzyme.

Answer: A. The inhibitor binds to the active site of the enzyme.

Butyric acid fermentation _____.

13:35 Add Comment

Butyric acid fermentation _____.



A. Metabolizes butyric acid.
B. Produces butyric acid.
C. Occurs independently of glycolysis.
D. Requires oxygen.
E. Works best without oxygen.


Answer: B. Produces butyric acid.

Which of the following statements are true?

13:35 Add Comment

Which of the following statements are true?



1 - Electron carriers are located at ribosomes.
2 - ATP is used to couple catabolic and anabolic pathways.
3 - ATP is used for the long-term storage of energy and so is often found in storage granules.
4 - Anaerobic organisms are capable of generating ATP via respiration.
5 - ATP can be generated by the flow of protons across protein channels.


A. 2, 4, 5
B. 1, 3, 4
C. 2, 3, 5
D. 1, 2, 3
E. All of the statements are true.


Answer: A. 2, 4, 5

Which of the following statements is true about enzymes?

13:35 Add Comment

Which of the following statements is true about enzymes?



A. Increasing temperature can change the substrates that can bind to the active site.
B. Decreasing temperature will speed up enzymatic reactions.
C. Apoproteins alone are nonfunctional.
D. A coenzyme is made of amino acids.


Answer: Apoproteins alone are nonfunctional.

Which of the following does not define fermentation?

13:34 Add Comment

Which of the following does not define fermentation?



A. Fermentation releases energy from sugars or other organic molecules.
B. Fermentation does not require oxygen, and can occur in the presence of oxygen.
C. Fermentation produces only small amounts of ATP (one or two ATP molecules for each molecule of starting material).
D. Fermentation requires the use of the Krebs cycle or an electron transport chain.


Answer: D. Fermentation requires the use of the Krebs cycle or an electron transport chain.

Which of the following pairs is mismatched?

13:30 Add Comment

Which of the following pairs is mismatched?



A) ionizing radiation — hydroxyl radicals
B) ozone — takes electrons from substances
C) plasma sterilization — free radicals
D) supercritical fluids — CO2
E) ultraviolet radiation — desiccation


Answer: e

Ethylene oxide

13:29 Add Comment

Ethylene oxide



A) is a good antiseptic.
B) is not sporicidal.
C) requires high heat to be effective.
D) is a sterilizing agent.
E) is the active chemical in household bleach.


Answer: d

An iodophor is a(n)

13:29 Add Comment

An iodophor is a(n) 



A) phenol.
B) agent that reduces oxygen.
C) quaternary ammonium compound.
D) form of formaldehyde.
E) iodine mixed with a surfactant.


Answer: e

Which of the following regarding antimicrobial control agents is FALSE?

13:28 Add Comment

Which of the following regarding antimicrobial control agents is FALSE?



A) Contaminating organic debris such as blood or sputum will decrease effectiveness.
B) Some agents kill by denaturing microbial cell proteins.
C) Some agents affect microbial cell membranes by dissolving lipids.
D) Some agents are utilized as both an antiseptic and a disinfectant.
E) A true antimicrobial control agent is equally effective against both bacteria and viruses.


Answer: e

All of the following factors contribute to hospital-acquired infections EXCEPT

13:27 Add Comment

All of the following factors contribute to hospital-acquired infections EXCEPT



A) some bacteria metabolize disinfectants.
B) gram-negative bacteria are often resistant to disinfectants.
C) invasive procedures can provide a portal of entry for bacteria.
D) bacteria may be present in commercial products such as mouthwash.
E) None of the answers is correct; all of these factors may contribute to hospital-acquired infection.



Answer: e

Which of the following is a limitation of the autoclave?

13:24 Add Comment

Which of the following is a limitation of the autoclave?



A) It requires an excessively long time to achieve sterilization.
B) It cannot inactivate viruses.
C) It cannot kill endospores.
D) It cannot be used with heat-labile materials.
E) It cannot be used with glassware.


Answer: d

Which of the following regarding antimicrobial control agents is FALSE?

13:24 Add Comment

Which of the following regarding antimicrobial control agents is FALSE? 



A) Contaminating organic debris such as blood or sputum decrease effectiveness.
B) Some agents kill by denaturing microbial cell proteins.
C) Some agents affect microbial cell membranes by dissolving lipids.
D) Silver is used for treating antibiotic-resistant bacteria.
E) Some agents inactivate viruses by attacking cell membrane lipids.


Answer: e

Which of the following pairs of terms is mismatched?

13:23 Add Comment

Which of the following pairs of terms is mismatched?



A) bacteriostatic — kills vegetative bacterial cells
B) germicide - kills microbes
C) virucide - inactivates viruses
D) sterilant — destroys all living microorganisms
E) fungicide — kills yeasts and molds


Answer: a

Which of the following best describes the pattern of microbial death?

13:23 Add Comment

Which of the following best describes the pattern of microbial death? 



A) The cells in a population die at a constant rate.
B) All the cells in a culture die at once.
C) Not all of the cells in a culture are killed.
D) The pattern varies depending on the antimicrobial agent.
E) The pattern varies depending on the species.


Answer: a

Select the correct statement about active and passive immunity.

13:20 Add Comment

Select the correct statement about active and passive immunity. 




A) Immunological memory is established by passive immunization.
B) A vaccination is an example of the introduction of passive immunity into the body.
C) The antibodies utilized in active immunity are acquired from another organism.
D) Active and passive humoral immunity are both mechanisms of adaptive immunity that use antibodies.


Answer: D) Active passive humoral immunity are both mechanisms of adaptive immunity that use antibodies

Select the correct definition about tissue grafts.

13:20 Add Comment

Select the correct definition about tissue grafts.



A) Isografts are between identical twins.
B) Allografts are between different species.
C) Xenografts are between individuals of the same species.
D) Autografts are between two genetically identical individuals.


Answer: A) isografts are between identical twins

Natural killer (NK) cells ________.

13:20 Add Comment

Natural killer (NK) cells ________.



A) are also called cytotoxic T cells
B) are a type of phagocyte
C) are cells of the adaptive immune system
D) can kill cancer cells before the immune system is activated


Answer: D) can kill cancer cells before the immune system is activated

Clonal selection of B cells ________.

13:20 Add Comment

Clonal selection of B cells ________.



A) occurs during fetal development
B) results in the formation of plasma cells
C) cannot occur in the presence of antigens
D) only occurs in the secondary immune response


Answer: B) results in the formation of plasma cells

Fever ________.

13:20 Add Comment

Fever ________.



A) is a higher-than-normal body temperature that is always dangerous
B) decreases the metabolic rate of the body to conserve energy
C) production is regulated by chemicals that reset the body's thermostat to a higher setting
D) causes the liver to release large amounts of iron, which seems to inhibit bacterial replication


Answer: C) production is regulated by chemicals that reset the body's thermostat to a higher setting

What is the role of interferon in defense against disease?

13:19 Add Comment

What is the role of interferon in defense against disease?



A) protects cells that have not yet been infected by viruses
B) protects cells that have not yet been infected by bacteria
C) activates the complement mechanism
D) activates the inflammatory process


Answer: A) protects cells that have not yet been infected by viruses

Which of the following is not a function of the inflammatory response?

13:19 Add Comment

Which of the following is not a function of the inflammatory response?



A) prevents the spread of the injurious agent to nearby tissue
B) replaces injured tissues with connective tissue
C) disposes of cellular debris and pathogens
D) sets the stage for repair processes


Answer: B) replaces injured tissues with connective tissue

Which statement is true about T cells?

13:19 Add Comment

Which statement is true about T cells?



A) They usually directly recognize antigens, which then activates a subpopulation of killer cells.
B) T-Cells only recognize fragments of antigenic proteins that have been processed and are presented.
C) Activated T-Cells produced antibodies.
D) T-Cells will develop into cytotoxic T cells if an antigen is complexed with class II MHC proteins.


Answer: B) T-Cells only recognize fragments of antigenic proteins that have been processed and are presented

B cells respond to the initial antigen challenge by ________.

13:18 Add Comment

B cells respond to the initial antigen challenge by ________.



A) reducing its size
B) immediately producing antigen-specific antibodies
C) forming of a large number of cells that are unlike the original B cell
D) producing progeny cells that include plasma cells and memory cells


Answer: D) producing progeny cells that include plasma cells and memory cells

Which of the following is associated with passive immunity?

13:18 Add Comment

Which of the following is associated with passive immunity?



A) exposure to an antigen
B) infusion of weakened viruses
C) passage of IgG antibodies from a pregnant mother to her fetus
D) booster shot of vaccine


Answer: C) passage of IgG antibodies from a pregnant mother to her fetus

The primary immune response ________.

13:17 Add Comment

The primary immune response ________.



A) occurs more rapidly and is stronger than the secondary response
B) occurs when memory cells are stimulated
C) is another name for immunological memory
D) has a lag period while B cells proliferate and differentiate into plasma cells


Answer: D) has a lag period while B cells proliferate and differentiate into plasma cells

Which of the following statements about Complement is false?

13:17 Add Comment

Which of the following statements about Complement is false? 



A) Complement consists of a group of at least 20 plasma proteins that normally circulate in the blood in an inactive form.
B) Complement can be activated through three pathways: classical, secondary, and alternate.
C) The membrane attack complex consists of complement proteins C5b - C9. The MAC creates pores in target cell membranes.
D) Immune clearance, which involves C3b binding Ag-Ab complexes to red blood cells, and macrophages removing and destroying the Ag-Ab complexes in the liver and spleen, is the principle method of clearing foreign antigens from the blood stream.


Answer: B) complement can be activated through three pathways: classical, secondary and alternate

Select the correct statement about the function of antibodies.

13:17 Add Comment

Select the correct statement about the function of antibodies. 



A) Antibodies may directly destroy "invaders."
B) Neutralization is the process by which antibodies cause invading cells to clump together.
C) The binding of antibodies to antigens marks the antigen to be destroyed by specific and nonspecific immune mechanisms.
D) IgG is found on mast cells and basophils.


Answer: C) the binding of antibodies to antigens marks the antigen to be destroyed by specific and nonspecific immune mechanisms

Antibody functions include all of the following except ________.

13:16 Add Comment

Antibody functions include all of the following except ________. 



A) binding and inactivating chemical toxins released by bacteria or other microorganisms
B) preventing migration of phagocytic cells away from the target site.
C) enhancing phagocytosis of pathogens
D) targeting foreign cells so that complement proteins can cause cellular lysis


Answer: B) preventing migration of phagocytic cells away from the target site

Phagocyte mobilization involves ________.

13:16 Add Comment

Phagocyte mobilization involves ________.



A) diapedesis, during which cells line up against the capillary wall
B) margination, which is the process of white cell movement through the walls of capillaries into injured tissues
C) mainly neutrophil and macrophage migration into inflamed areas
D) monocytes as the most active phagocyte


Answer: C) mainly neutrophil and macrophage migration into inflamed areas

Select the correct statement about antigens.

13:16 Add Comment

Select the correct statement about antigens.



A) "Self-antigens" is another name for incomplete antigens.
B) The largest type of antigen is called a hapten.
C) Only small antigens exhibit reactivity.
D) One antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody.


Answer: D) one antigen may have many different antigenic determinants and may therefore cause the formation of more than one antibody

Which of the following statements regarding NK cells is a false or incorrect statement?

13:15 Add Comment

Which of the following statements regarding NK cells is a false or incorrect statement?



A) NK cells are a type of neutrophil.
B) NK cells are present in the blood, spleen, lymph nodes, and red bone marrow.
D) NK cells attack cells that display abnormal MHC antigens.
E) NK cells attack cancer cells and virus-infected body cells.


Answer: A) NK cellar a type of neutrophil

Which of the following statements is incorrect or false?

13:15 Add Comment

Which of the following statements is incorrect or false?



A) Fragments of endogenous antigens combine with MHC molecules outside of the infected cells.
B) MHC antigens are inherited antigens that are located in the plasma membranes of all body cells except for red blood cells.
C) Antigen presenting cells engulf antigens and then present fragments of the antigens on their own surfaces where T-cells can recognize them.
D) MHC proteins are the cell's identity markers.


Answer: A) fragments of endogenous antigens combine with MHC molecules outside of the infected cells

Complement proteins and antibodies coat a microorganism with C3b which enhances phagocytosis of the pathogen by neutrophils and macrophages. This phenomenon is termed ________.

13:14 Add Comment

Complement proteins and antibodies coat a microorganism with C3b which enhances phagocytosis of the pathogen by neutrophils and macrophages. This phenomenon is termed ________.



A) diapedesis
B) agglutination
C) opsonization
D) chemotaxis


Answer: C) opsonization

Interferons ________.

13:14 Add Comment

Interferons ________.



A) are virus-specific, so that an interferon produced against one virus could not protect cells against another virus
B) act by increasing the rate of cell division
C) interfere with viral replication within cells
D) are routinely used in nasal sprays for the common cold


Answer: C) interfere with viral replication within cells

Cytotoxic T cells ________.

13:14 Add Comment

Cytotoxic T cells ________. 



A) are the only T cells that can directly attack and kill other cells
B) require the double recognition signal of I MHC plus II
C) MHC on the target cell in order to function
D) function mainly to stimulate the proliferation of other T cell populations
E) self-destruct once the antigen has been neutralized

Answer: A) are the only T cells that can directly attack and kill other cells

Helper T cells ________.

13:13 Add Comment

Helper T cells ________.



A) bind tightly to target cells and release a lymphotoxin called perforin
B) often function to decrease the immune response
C) release B7 proteins
D) function in the adaptive immune system activation



Answer: D) function in the adaptive immune system activation

Which of the following is true of hypersensitivities?

13:12 Add Comment

Which of the following is true of hypersensitivities? 



A) They occur when a person's Killer T-Cells attack their own tissues.
B) They are are adaptive immune responses to disease organisms.
C) They include diabetes mellitus and SCID.
D) They involve IgE antibodies and the release of histamine from mast cells and basophils.


Answer: D) They involve IgE antibodies and the release of histamine from mast cells and basophils.

Vaccination stimulates:

13:08 Add Comment

Vaccination stimulates: 



A) natural active immunity.
B) artificial active immunity.
C) natural passive immunity.
D) artificial passive immunity.
E) artificial specific immunity.


Answer: B) artificial active immunity

______ occurs when an intravenous injection of antibodies, bsuch as gamma globulin is administered to someone as a treatment. The serum used for emergency treatment of snakebites is an example of this type of immunity.

13:06 Add Comment

______ occurs when an intravenous injection of antibodies, bsuch as gamma globulin is administered to someone as a treatment. The serum used for emergency treatment of snakebites is an example of this type of immunity. 



A) Artificial passive immunity.
B) Artificial active immunity.
C) Natural passive immunity.
D) Natural active immunity.
E) Artificial specific immunity.


Answer: A) Artificial passive immunity

What types of microbes live in the intestines?

13:02 Add Comment

What types of microbes live in the intestines?



A) Diverse species of bacteria, archaea, and fungi, especially Bacteroides and Firmicutes bacteria
B) A narrow range of bacteria, especially Firmicutes
C) A narrow range of bacteria and fungi, especially Bacteroides
D) Archaea and fungi only


Answer: A) Diverse species of bacteria, archaea, and fungi, especially Bacteroides and Firmicutes bacteria

Which of the following is NOT a way the normal microbiota of the intestine helps to prevent infection?

13:02 Add Comment

Which of the following is NOT a way the normal microbiota of the intestine helps to prevent infection?



A) It produces acids that lower the pH of the stomach.
B) It speeds up the process by which microbes are flushed from the digestive tract.
C) It consumes food and occupies space, outcompeting potential pathogens.
D) It generates large quantities of oxygen that kill anaerobic pathogens.


Answer: D) It generates large quantities of oxygen that kill anaerobic pathogens.

Which of the following factors can lead to the reemergence of a disease?

13:02 Add Comment

Which of the following factors can lead to the reemergence of a disease?


A) A mutation that allows it to infect humans
B) A period of decline in vaccination rates
C) A change in disease reporting procedures
D) Better education on the signs and symptoms of the disease


Answer: B) A period of decline in vaccination rates

Mercury is a toxic compound and is a problem in our environment. As a microbiologist you know that certain types of bacterial strains could be coerced into cleaning up our environment. What is this concept called?

13:01 Add Comment

Mercury is a toxic compound and is a problem in our environment. As a microbiologist you know that certain types of bacterial strains could be coerced into cleaning up our environment. What is this concept called?



A) Bioremediation
B) Biological Sanitization
C) Biocleaning
D) Microbial Cleansing


Answer: A) Bioremediation

Normal microbiota protect the host by:

12:58 Add Comment

Normal microbiota protect the host by:



A) Occupying niches that pathogens might occupy
B) Degrading antibiotics
C) Producing bacteriocins and/or acids
D) A and C
E) A and B


Answer: D) A and C
Subscribe to: Posts (Atom)