Why are some pathogenic bacteria able to make toxins?

Answers

Answer 1
A pathogen is a microorganism that is able to cause disease in a plant, animal or insect. Pathogenicity is the ability to produce disease in a host organism. Microbes express their pathogenicity by means of their virulence, a term which refers to the degree of pathogenicity of the microbe. Hence, the determinants of virulence of a pathogen are any of its genetic or biochemical or structural features that enable it to produce disease in a host.

The relationship between a host and a pathogen is dynamic, since each modifies the activities and functions of the other. The outcome of such a relationship depends on the virulence of the pathogen and the relative degree of resistance or susceptibility of the host, due mainly to the effectiveness of the host defense mechanisms. Staphylococcus aureus, arguably the most prevalent pathogen of humans, may cause up to one third of all bacterial diseases ranging from boils and pimples to food poisoning, to septicemia and toxic shock. Electron micrograph from Visuals Unlimited, with permission.

The Underlying Mechanisms of Bacterial Pathogenicity

Two broad qualities of pathogenic bacteria underlie the means by which they cause disease:
1. Invasiveness is the ability to invade tissues. It encompasses mechanisms for colonization (adherence and initial multiplication), production of extracellular substances which facilitate invasion (invasins) and ability to bypass or overcome host defense mechanisms.

2. Toxigenesis is the ability to produce toxins. Bacteria may produce two types of toxins called exotoxins and endotoxins. Exotoxins are released from bacterial cells and may act at tissue sites removed from the site of bacterial growth. Endotoxins are cell-associated substance. (In a classic sense, the term endotoxin refers to the lipopolysaccharide component of the outer membrane of Gram-negative bacteria). However, endotoxins may be released from growing bacterial cells and cells that are lysed as a result of effective host defense (e.g. lysozyme) or the activities of certain antibiotics (e.g. penicillins and cephalosporins). Hence, bacterial toxins, both soluble and cell-associated, may be transported by blood and lymph and cause cytotoxic effects at tissue sites remote from the original point of invasion or growth. Some bacterial toxins may also act at the site of colonization and play a role in invasion. Acid-fast stain of Mycobacterium tuberculosis, the agent of tuberculosis (TB). The bacteria are the small pink-staining rods. More than one-third of the world population is infected. The organism has caused more human deaths than any other bacterium in the history of mankind. Although its ability to produce disease is multifactorial, it is not completely understood. American Society of Microbiology, with permission.

Related Questions

Which statement accurately describes radioactive dating?

A.Geologists use only one type of radioactive dating.
B.Geologists compare parent and daughter elements to determine rock type.
C.Geologists will measure how stable multiple parent elements can decay into multiple daughter elements.
D.Geologist compare the observed abundance of naturally occurring radioactive isotopes and their decay products using decay rates.

Answers

Answer:

D. Geologist compare the observed abundance of naturally occurring radioactive isotopes and their decay products using decay rates.

Explanation:

Radioactive dating is the method in which radioactive isotopes are employed to evaluate the age of rocks and ores. There are many complex radioisotopes utilized for radioactive dating is like Potassium, Uranium, and Carbon. Radioactive dating operates on the system that a radioactive isotope can fade into the constant daughter nuclei at a steady rate. Geologist commonly uses the system for half life. Half-life is the time needed for half of the radioactive element to decline. This is fixed for a selective element.

Answer: D

Explanation:

Where do the mineral resources in which society depends on come from

Answers

Answer:Without minerals we would not have electricity, food, or shelter. Minerals make today's technology-based life possible, but that's something many of us take for granted.

Explanation:Soil, rocks, and minerals provide essential metals and other materials for agriculture, manufacturing, and building. 7.7. Earth scientists and engineers develop new technologies to extract resources while reducing the pollution, waste, and ecosystem degradation caused by extraction.

how have co2 levels changed since 1870

Answers

Answer:

raised atmospheric concentrations of CO2 by 47% above pre-industrial levels

Explanation:

Over the past 170 years, human activities have raised atmospheric concentrations of CO2 by 47% above pre-industrial levels found in 1850. This is more than what had happened naturally over a 20,000 year period (from the Last Glacial Maximum to 1850, from 185 ppm to 280 ppm).

What portions of RNA are cut out and discarded during the process of RNA editing

Answers

Answer:

 introns are portions of RNA that are cut out and discarded.

Explanation:

Please someone helpp pleassseee pleaseeee

Answers

Answer:

Honeybees and Flowers

Honeybees and flowers

The simplest structures that can carry out all of the activities characteristic of life are:
A. cells.
B. atoms.
C. molecules.
D. crystals.

Answers

atoms as they are the simplest

The cell part that helps with cell division is the ________​

Answers

Answer:

centrioles

Explanation:

Every animal-like cell has two small organelles called centrioles. They are there to help the cell when it comes time to divide. They are put to work in both the process of mitosis and the process of meiosis.

True of False: Marsh was able to prove that animals changed over time.

Answers

Answer:

True

Explanation:

Hope this helps :D Have a great day..can i hav brainliest?

I think the answer is true


:):):):):):):):)

Based on the diagram below, at which point is the most oxygen being
produced?
Oxygen in Plants and Time of Day
D
Dawn
Dusk
Dawn
OA. Point B
O B. Point C
OC. Point A
O D. Point D

Answers

Answer:

Point C dusk

Explanation:

if you follow the chart, the highest point is point C

Why is biodiversity important for ecosystems?

Answers

Answer:to stop from extinction

Explanation:

All cells in an organism have the same copy of DNA, because they all came from the same orginal cell.
True Or False

Answers

the answer would be true

An example of __ is the color of betta fish. When a RED fish (GG) is crossed with a YELLOW fish (gg), all of the offspring will be a ORANGE color (Gg)

Answers

Answer:

The correct answer is  - incomplete dominance.

Explanation:

In the betta fish, there are different types of colors found in the fishes depends on the alleles present in their gene which follows incomplete dominance. Incomplete dominance is an inheritance pattern where a dominant allele does not mask completely and produce a blend of both alleles if present in heterozygous condition.

In the question, It is stated that when a cross between RED fish (GG) and a YELLOW fish (gg) produce orange color fish as offspring (Gg) which is a mix or blend of both alleles Red (dominant) and yellow (recessive).

Creep is a type of erosion caused by


glacial erosion

gravity erosion

gully erosion

wind erosion

Answers

Answer:  Understanding different types of erosion, by water or wind, can help us protect our soils. ... Causes. Gully development may be triggered by: cultivation or grazing on ... Gravity moves earth, rock and soil material downslope both slowly ... soil creep; earthflow; slumping; landslips; landslides; rock avalanches.

Explanation:

Sexual reproduction is a process by?

Answers

Answer:

Sexual reproduction begins with sperm and egg cells, which are produced through a process called meiosis. ... In sexual reproduction, a haploid sperm from the male parent fertilizes the haploid egg from the female parent to produce what is called a diploid zygote. Zygote is the technical term for a fertilized egg.

Sperm lol hope this helps

what is the meaning of biosphere​

Answers

Answer:

The biosphere is a global ecosystem composed of living organisms (biota) and the abiotic (nonliving) factors from which they derive energy and nutrients. Earth's environmental spheres. Earth's environment includes the atmosphere, the hydrosphere, the lithosphere, and the biosphere.

Explanation:

''.''

Biosphere, relatively thin life-supporting stratum of Earth's surface, extending from a few kilometres into the atmosphere to the deep-sea vents of the ocean. The biosphere is a global ecosystem composed of living organisms (biota) and the abiotic (nonliving) factors from which they derive energy and nutrients.

What is the energy source that allows photosynthesis to occur?

Answers

Answer:

[tex]\boxed {\boxed {\sf The \ sun }}[/tex]

Explanation:

Photosynthesis is a special process that certain organisms (plants, algae, and some bacteria) undergo to create "food".

This turns light energy, carbon dioxide, and water into glucose and oxygen. The glucose becomes the food for the organism, because it is turned into ATP during cellular respiration. The ATP is energy that fuels the processes, like growth, repair, and transport.

This process occurs because of the sun. It provides the light energy needed for the reaction. Organelles inside of the cells, called chloroplasts, contain a pigment (chlorophyll) that captures this energy.

rko vs claymore who will win​

Answers

Answer:

claymore duh

Explanation:

Answer:

claymore

Explanation:

what would happen if an electric fish was always negatively charged instead?​

Answers

Answer:

Electric eels are part of a group of animals called electric fish.These cells pump positively charged sodium atoms, called ions, from inside themselves to the outside.

Explanation:

Brainliest? plz

Electric fish is a part of the group of animals which are responsible for producing charge. These organisms pump positively charged sodium ions from inside themselves to the outside environment.

What is electric fish?

An electric fish is an fish that can generate electric fields and transfer current through themselves. Most of the electric fishes are electroreceptive, which means that these fishes can sense the electric fields present in the environment. The only exception here is the stargazer family which is not electroreceptive.

The examples of electric fish includes Electric eel, that belongs to the genus Electrophorus, South American knifefishes responsible for the production of powerful electric shocks to stun prey.

If the electric fishes are supplied with the negative charge always then they will pump positive charge to neutralize the effect of that charge.

Learn more about Electric fish here:

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Answer this please I promise 30 points + mark as brainliest ( only relevant answers )

Answers

Answer:

X could be an Arecaceae

Both roses and ferns are used as ornamental plants

Explanation:

Hope I got this right!! I really love plants! aslo feel free to report this answer if I was wrong!

which of the following solutions will best enable Josey to see the onion cells detail?

Answers

I have 2 answers a and d but i think its d i am not sure if it’s correct

write the difference
between mitosis and mieosis


please give me the answer

don't spam​

Answers

Answer:

Meiosis is the type of cell division that creates egg and sperm cells. Mitosis is a fundamental process for life.

Explanation:

mitosis is same number

and mieosis _ half number

Poly" means many and "saccharide" means sugar. Why is
polysaccharide a good name for the picture on the right above

Answers

Answer: The name means many sugars, so polysaccharide meaning many sugars works for it.

Explanation:

Which antivenom will save Tyler?

Select one:

a.
Antivenom A


b.
Antivenom B


c.
Antivenom C


d.
Antivenom D

Answers

the answer is anticenom A

Answer:

A

Explanation:

It is A

Why are bananas curved?

Answers

Answer:

It's because of the sun! Bananas are curved so they can retrieve sunlight. Bananas go through a process called 'negative geotropism'.What it means is that bananas grow away from the ground, instead of growing towards it, hence the 'negative' geotropism.

Explanation:

g.o.o.g.l.e lma o

Answer

It's because of the sun!

Explanation:

Bananas are curved so they can retrieve sunlight. Bananas go through a process called 'negative geotropism'. Meaning it grows away from the ground instead of towards it.

What is the function of a phospholipid bilayer

Answers

Answer:

Phospholipid bilayers create a selectively permeable barrier to the movement of ions and molecules important for cellular function.

Answer: The phospholipid bilayer acts as a barrier to the passage of molecules.

Use your knowledge of inheritance (the passing of traits from parents to offspring) to explain why
these twins look so different even though they have the same parents. Why aren't they identical? In
your answer you should include your knowledge of gametes (sperm and egg), chromosomes, and
variation

Answers

Answer:

Fraternal twins can be different genders because they are two completely different eggs getting fertilized; but even two same gender fraternal twins do not look completely alike. Whereas for identical twins since one egg is splitting into two, the two cells have the same exact DNA make up and chromosomes.

I also believe the technical part of it is to do with genetics, like ressesive and dominant genes, because they can be the same gender, ex. both girls and one has blue eyes, fair skin, and blonde hair, the other twin has brown eyes, black hair and tan skin. The parents could be part of the genes but there is also grandparents maybe the mom's mom has blonde hair and blue eyes, with fair skin. But the dad he has brown eyes, black hair and tan skin. The moms genes were recessive, but the grandma's genes were dominant.

I tried to explain it as best as I could I hope it helps!

What occurs during the digestion of proteins?
A) Specific enzymes break down proteins into amino acids
B) Specific hormones break down proteins into simple sugars
c) Specific hormones break down proteins into complex carbohydrates
D) Specific enzymes break down proteins into simple sugars

Answers

Answer:

Specific enzymes break down proteins into amino acids

The process happens in the digestion of proteins, specific enzymes break down proteins into amino acids.

What are enzymes?

Enzymes are the proteins that are helpful in the increasing the rate of any reaction. Enzymes also present in the body, they help in digestion of different substances in the body. Different enzymes work on different substances.

Thus, the correct option is A) Specific enzymes break down proteins into amino acids.

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what factors create deserts

Answers

Answer:

Air is forced to rise over mountains, air cools and condensation occurs, rain falls over the mountains, dry air sinks down the other side of the mountain. Some deserts form in areas that lie at great distances from the sea. The air here is much drier than on the coast.

Explanation:

Michael loves playing his clarinet and believes it attracts more rabbits than any other instrument he
has played. In order to test his hypothesis, Michael played a song on his clarinet for a total of 5
minutes and counted the number of rabbits he saw in his front yard. He played the song a total of 3
times on his clarinet and repeated the experiment using a flute and a guitar. He also recorded the
number of rabbits he observed when he was not playing an instrument. The results are shown in the
chart.
Number of Rabbits
TRIAL
NO MUSIC
CLARINET
FLUTE
GUITAR
15
1
2
3
5
3
2
10
12
5
8
9
12
18
7
1) What is the independent variable?
2) What is the dependent variable?
3) What is the experimental group?
4) What is the control group?
5) What is one constant from the experiment above??

Answers

Answer:

Independent variable: type of instrument

Dependent variable: Number of rabbits attracted

Experimental group: The group when he played an instrument

Control group: The group when not playing an instrument

Constant: Same song

Explanation:

1. Independent variable is the variable that the experimenter changes or manipulates in an experiment. In this experiment, the variable that is changed is the TYPE OF INSTRUMENT used (clarinet, flute, guitar), hence, it is the independent variable.

2. Dependent variable is the variable that is measured in an experiment. It is the variable that responds to the changes made to the independent variable. In this experiment, the dependent variable is the "NUMBER OF RABBITS ATTRACTED" by the instrument played.

3. Experimental group is the group of an experiment that receives experiment treatment, which is the independent variable. In this case, the experimental group is the GROUP IN WHICH INSTRUMENT WAS PLAYED.

4. Control group is the group that does not receive the experimental treatment. In this case, the control group is the group in which INSTRUMENT WAS NOT PLAYED.

5. Constants are those variables that remains unchanged for all groups throughout the experiment. In this case, one constant is the SAME SONG played.

Describe the process of water moving in and out of the cell.

Answers

Answer:

Water moves across cell membranes by diffusion, in a process known as osmosis. Osmosis refers specifically to the movement of water across a semipermeable membrane, with the solvent (water, for example) moving from an area of low solute (dissolved material) concentration to an area of high solute concentration.

Explanation:

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