Which type of bacterial enzyme helps spread streptococcus pyogenes by digesting blood clots?

The Elements of Life

In biology, the elements of life are the essential building blocks that make up living things. They are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. The first four of these are the most important, as they are used to construct the molecules that are necessary to make up living cells. These elements form the basic building blocks of the major macromolecules of life, including carbohydrates, lipids, nucleic acids and proteins. Carbon is an important element for all living organisms, as it is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. Even the cell membranes are made of proteins. Carbon is also used to construct the energy-rich molecules adenosine triphosphate (ATP) and guanosine triphosphate (GTP). Hydrogen is used to construct the molecules water and organic compounds with carbon. Hydrogen is also used to construct ATP and GTP. Nitrogen is used to construct the basic building blocks of life, such as amino acids, nucleic acids, and proteins. It is also used to construct ATP and GTP. Oxygen is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids. It is also used to construct ATP and GTP. Phosphorus is used to construct the basic building blocks of life, such as carbohydrates, lipids, and nucleic acids.

Índice Show

Which enzyme would help bacterial pathogens spread through tissue by destroying protein structures?
What enzymes are produced by Staphylococcus aureus but is not produced by Streptococcus pyogenes?
Are various bacterial enzymes that dissolve fibrin clots?
Are Exoenzymes that dissolve clots?

Enzymes. Many pathogens produce a series of enzymes to help overcome body defenses and establish themselves in the host. One example is leukocidins, a group of enzymes that destroy white blood cells. This destruction lessens the body's ability to perform phagocytosis.

Other bacterial enzymes are hemolysins. These enzymes destroy red blood cells. Streptococci, staphylococci, and certain Clostridium species produce hemolysins.

Coagulases are bacterial enzymes that clot the blood. These enzymes convert fibrinogen into fibrin, which forms the threads of a blood clot. The clot helps staphylococci avoid the body's phagocytes and contributes to its pathogenicity.

Other important enzymes are streptokinase and hyaluronidase. Streptokinase is a streptococcal enzyme that dissolves blood clots. This activity helps the organism escape the body's attempt to wall off an infection. Hyaluronidase destroys hyaluronic acid, a polysaccharide that “cements” cells together in a tissue. Hyaluronidase thus permits organisms to spread through tissues and establish themselves at sites distant from that of the intial infection. Another enzyme, called collagenase, breaks down collagen in the connective tissues of muscles. It thereby encourages the spread of infection.

Toxins. Many bacteria are able to produce poisonous substances called toxins. Toxins act on the body's cells, tissues, and organs and interfere with important body processes, thereby interrupting normal body functions. Those microorganisms that produce toxins are said to be toxigenic. The condition in which toxins are produced is called toxemia.

Two important types of toxins are exotoxins and endotoxins. Exotoxins are proteins produced by bacteria during their growth and liberated into their surrounding environment. Exotoxins are produced chiefly by Gram‐positive bacteria, and the genes for this production are carried primarily on the plasmids.

Various types of exotoxins exist. Neurotoxins interfere with the nervous system, while enterotoxins interfere with activities of the gastrointestinal tract. In response to toxins, the body produces special antibodies called antitoxins, which unite with and neutralize the toxins, providing defense against disease.

It is possible to immunize against the effects of exotoxins by injecting toxoids into individuals. Toxoids are preparations of exotoxins chemically treated to destroy their toxigenicity but retain their ability to elicit antibody formation in the body. Toxoids are currently available to protect against diphtheria and tetanus (the DT injection).

Endotoxins are portions of the cell wall of Gram‐negative bacteria. They consist primarily of lipopolysaccharides and are released when bacteria break apart during the process of lysis. Since lysis occurs during antibiotic therapy, the effects of endotoxins can bring about a worsening of symptoms during the recovery period. This condition is called endotoxin shock. It is accompanied by fever, chills, aches, and cardiovascular collapse.

What do hyaluronidase and kinase have in common?

They are both enzymes involved in evading host defense.

According to your Concept Map, which of the following organisms exhibits antigenic variation?

Which of the following virulence factors could directly prevent phagocytosis and/or phagocytic degradation?

all of the above- capsules, M proteins, waxy lipids.

In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true?

Shiga toxin is more lethal than staphylococcal enterotoxin.

Which of the following would be an example of an infection initiated via the parenteral route?

An individual contracts hepatitis B from an accidental stick with a contaminated needle.

Which statement regarding endotoxins is true?

One consequence of endotoxins is the activation of blood-clotting proteins.

Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots?

In which of the following cases would the Limulus amebocyte lysate (LAL) assay be used?

to ensure that a sterilized medical device is free of endotoxin

Which of the following toxins does NOT match the description?

Vibrio enterotoxin: a superantigen that destroys epithelial cells

Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage?

The most frequently used portal of entry for pathogens is the

mucous membranes of the respiratory tract.

The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the hosts antibodies is called

Most pathogens that gain access through the skin

enter through hair follicles and sweat ducts.

Which of the following statements is FALSE?

Coagulase destroys blood clots.

Which of the following statements about exotoxins is generally FALSE?

They are resistant to heat.

part of the gram-negative cell wall.

Cytopathic effects are changes in host cells due to

Many pathogens use the same portal for entry and exit from the body.

Most symptoms of endotoxins can be treated with administration of anti-endotoxin antibodies.

Ergot and aflatoxin are toxins sometimes found in grains contaminated with fungi.

In A-B exotoxins, the A component binds to the host cell receptor so that the B component can enter the cell.

Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections.

The M protein enhances the virulence of Streptococcus by preventing phagocytosis.

Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by

In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes

a decrease in blood pressure.

Bacteria such as E. coli and Salmonella produce invasins that bind host cells, thus causing the cells to

All of the following bacteria release endotoxin EXCEPT

Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?

Which of the following is NOT a membrane-disrupting toxin?

All of the following are methods of avoiding host antibodies EXCEPT

membrane-disrupting toxins.

All of the following organisms produce exotoxins EXCEPT

Which of the following statements about staphylococcal enterotoxin is FALSE?

It is produced by Staphylococcus aureus growing in the host's intestines.

Which enzyme would help bacterial pathogens spread through tissue by destroying protein structures?

Hyaluronidase thus permits organisms to spread through tissues and establish themselves at sites distant from that of the intial infection. Another enzyme, called collagenase, breaks down collagen in the connective tissues of muscles. It thereby encourages the spread of infection. Toxins.

What enzymes are produced by Staphylococcus aureus but is not produced by Streptococcus pyogenes?

epidermidis is normally non-pathogenic but can produce disease under certain conditions. The staphylococci produce the enzyme catalase that distinguishes them from the streptococci which do not. By definition, strains of staphylococci that produce the enzyme coagulase are S.

Are various bacterial enzymes that dissolve fibrin clots?

The plasmin is a crucial enzyme in the dissolution of fibrin clots.

Are Exoenzymes that dissolve clots?

Extracellular enzymes (exoenzymes) lyse cells, form or dissolve clots, and dissolve materials in tissue. Leukocidins: Destroy white blood cells that are phagocytes.