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1.) All fungi are heterotrophic and can break their substrates down by secreting enzymes. True or False.

2.) Fungi that exhibit thermal dimorphism grow as yeasts at 25-30 C and as molds at 37 C. True or False.

3.) Aspergillus can cause infections of the sinuses and ear canals. True or False.

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Bunny Greenfelder
Bunny GreenfelderLv2
28 Sep 2019

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Related questions

16. All of the following are true about ear infections EXCEPT:

Middle ear infections (otitis media) often produce a puslike exudate (referred to as otitis media with effusion) due to infection by genera of Streptococcus, Haemophilus, or various species of anaerobes.

External auditory canal (otitis externa) infections are typically caused by Staphylococcus aureus or Pseudomonas aeruginosa.

After successful treatment of middle ear infections with antibiotics, sometimes tubes are inserted to prevent fluid accumulation, repeated infections, and hearing loss.

Pseudomonad infections are common in swimmers because these organisms are able to produce a soluble greenish-blue pigment.

Repeated ear infections in children often decrease markedly because as the child ages and the Eustachian tube changes shape and develops an angle that prevents most organisms from reaching the middle ear.

17. Why are colds difficult to treat and prevent?

Different cold viruses predominate during different seasons.

Because there are so many different types of rhino- and coronaviruses, each with different antigens, development and administration of vaccines are currently prohibitive.

Although some human interferons have been shown to block or limit rhinovirus infections, delivery to infection sites is difficult, and unwanted side effects can occur.

All of the above.

Both a and c.

18. Which of the following is NOT true about parainfluenza viruses?

Most infants by the age of 6 months have been exposed to and develop antibodies against all 4 parainfluenza viruses.

They cause rhinitis characterized by nasal, pharyngeal, and bronchial inflammation, primarily in children.

Parainfluenza virus infection can be prevented by vaccination.

They can cause noisy respiration (stridor) and acute obstruction of the larynx called croup.

The viruses are spread by direct contact or by large droplets.

19. In whooping cough, patients experience violent coughing episodes during the _________ stage and can have bluing of the skin or _________ due to lack of oxygen from massive mucus and bacterial airway blockage.

Paroxysmal; cyanosis

Catarrhal; pigmentation

Convalescent; osmosis

Pneumotic; hydrolysis

Primary; emesis

20. Penicillins have no effect on Mycoplasma pneumoniae because:

Mycoplasmas are viruses

Mycoplasmas possess beta lactamases

Mycoplasmas are too small

Mycoplasmas are eukaryotes

Mycoplasmas lack cell walls

21. How many cases of tuberculosis are reported globally each year?

10

10,000

100,000

3 million

10 million

22. Mycobacteria are difficult to Gram stain, and are termed “acid-fast” due to their:

Ability to survive in acidic conditions

Resistance to drying

Thick, waxy cell walls

Resistance to sunlight

Lack of a peptidoglycan layer

23. Which of the following is true about pathogenic mycobacteria?

They have a long generation time of 12 to 18 hours.

They are obligate anaerobes sensitive to small amounts of oxygen.

They are highly resistant to drying and can remain viable in dried sputum 6 to 8 months later.

Both a and b.

Both a and c.

24. Clinical symptoms of tuberculosis are primarily due to:

Host inflammatory response

Mycotoxins

Endotoxin

Mucus production

Exotoxin

25. What characteristic of Coxiella burnetii, the causative agent of Q fever, allows it to survive for up to 2 years?

Metachromatic granule

Exotoxin

Endospore

Hemagglutinin

Cilia

26. The normal microflora of the heart includes species of:

Gram-positive bacteria

Gram-negative bacteria

Fungi

Viruses

None of these

27. Which of the following is commonly directly responsible for causing septic shock today?

Bacterial hemagglutinins

Bacterial endotoxins

Bacterial exotoxins

Fungal aflatoxins

Bacterial neurotoxins

28. All of the following are symptoms of septic shock EXCEPT

Shock

Lymphangitis

Chills

Fever

Collapsed blood vessels

29. What is the most likely explanation of how Streptococcus pyogenes causes rheumatic fever?

Strep throat infections migrate down to the heart.

Endotoxin production causes septicemia.

Vegetation followed by fibrin deposition.

Cross-reactivity of an antibody for a Streptococcus pyogenes antigen to a heart cell antigen.

It is an opportunistic infection triggered by coronary artery disease and atherosclerosis.

30. Bacterial endocarditis is an infection and inflammation of the lining and valves of the heart and occurs as a result of transient bacteria attaching to fibrin from exposed collagen fibers of damaged valvular surfaces. True or false?

can you please give me a response for this Article(type the anwer)

When a soil dries out, this has a negative impact on the activity of soil bacteria. Using an innovative combination of state-of-the-art analysis and imaging techniques, researchers at UFZ have now discovered that fungi increase the activity of bacteria in dry and nutrient-poor habitats by supplying them with water and nutrients. The ability of fungi to regulate drought stress in soil and thus sustain ecosystem functions is an important insight in the context of climate change.

Many fungi spread through the soil with a fine network of thin filaments known as hyphae. In their search for water and nutrients the hyphae grow in different directions, constantly enlarging the network. Once found, water and nutrients are absorbed and transported through the hyphae, allowing them to be supplied to parts of the fungal network in dry or nutrient-poor areas of the soil. But it isn't only the fungus itself which benefits from the transport of material through the hyphal pipelines: bacteria, too, are kept supplied with the water and nutrients they need to thrive. This has now been demonstrated by a team of UFZ researchers in a study recently published in the journal Nature Communications. "We've suspected for a long time that fungi play an important role in the soil moisture budget," says UFZ environmental biotechnologist Prof. Matthias Kästner. "Now, using secondary ion mass spectrometry techniques (NanoSIMS and ToF-SIMS) from the ProVIS research platform at UFZ, we've finally obtained experimental evidence."

As part of their investigations, the researchers closely examined the transport of water, substrates and nutrients through the microscopically small hyphae of fungi. They grew the fungi on a culture medium of water, glucose and nitrogen-containing nutrients. The fungal hyphae had to pass through a dry, nutrient-free zone in order to grow through into a new area containing the culture medium. The inhospitable transition zone contained spores of the common soil bacterium Bacillus subtilis. Spores are inactive stages of Bacillus that form when there is insufficient water, food and nutrients available for bacterial growth. The bacteria go into a kind of dormant stage, from which they only awake once the environmental conditions are more favourable for living again.

In the experiment, these conditions were indeed improved by the growth of the fungi: "As the fungal hyphae grew through the dry zone, the bacterial spores germinated and we noticed clear microbial activity," says UFZ environmental microbiologist Dr. Lukas Y. Wick. "The fungi obviously improved the environmental conditions for the bacteria and woke them from their slumber, like Sleeping Beauty." But what exactly happens at a chemical level when fungal hyphae grow in direct proximity to bacterial spores? To answer this question, the researchers 'labelled' the water, glucose and nitrogen-containing nutrients in the culture medium in advance with stable isotopes. If these substances were transferred from the fungus to the bacteria, they could be detected using the isotopic marker and the NanoSIMS method, with nano-scale spatial resolution. "The NanoSIMS method reveals the distribution of elements and isotops and therefore allows us to observe metabolic processes," Kästner explains. "As it turns out, we did find the stable isotopes of the labelled water, glucose and nitrogen-containing nutrients in the cell mass of the bacteria -- which could only have come from the fungi."

This study has given the UFZ researchers another important insight into fungi and their important function in soils. Fungi serve as pumping stations and pipelines for water, substrates and nutrients and can colonise inhospitable locations, making them habitable for bacteria -- and thus stimulate microbial activity in the soil. In previous work the researchers have already shown that fungal hyphae act as a kind of fungal highway for bacteria, allowing them to move around, and provide a hotspot for bacterial gene transfer. Wick continues: "The results of this latest study demonstrate once again that, through their interaction with bacteria, fungi play a significant, previously underestimated role in the soil ecosystem."

If a soil is contaminated with pollutants, for example, bacteria can break them down. But if the soil is too dry, the degradation processes will come to a standstill. "If the drought period lasts for a limited time, fungi have a stabilising effect and can keep soil processes going. This could be important specifically with regard to the impacts of climate change, if the ratio of dry to moist areas of soil dramatically increases," says Kästner. In future investigations, the researchers therefore intend to look even more closely at soil as a true ecosystem. "We want to carry out soil experiments under different environmental conditions and find out what influence fungal growth has on the breakdown of pollutants," says Wick. He adds: "It's important to have a better understanding of the role of fungi in the soil ecosystem. Only when we know how soil works can we respond to changes, for example those caused by climate change, with informed decisions."

Enzyme Activity

1. Briefly explain the principle of spectrophotometry.

2. Which of the following statements is true about enzymes?(check all correct answers)

__ enzymes act on (are specific for) one or just a fewsubstrates

__ enzymes can be denatured (loose their tertiary/quaternarystructure and activity) by extreme conditions such as heat, high orlow pH,or presence of organic solvents

__most enzymes are DNA

__ enzymes are protein

__enzymes perform best at specific conditions of temperature, pHand salt concentration

5. Which enzymes break the following macromolecules?

Match the following with their correponding answers:

___ Nucleic acids A. proteases or proteinases such as pepsin

___ Cellulose B. none

___ Triglycerides C. lipases

___ Proteins D. amylases

___ Starch E. nucleases

6.Match the following enzymes totheir products.

Answers

___ pepsin, trypsin and other digestive proteases A.Nucleotides

___ salivary and pancreatic amylases and other enzymes B. AminoAcids

___ lipases C. Monosaccharides

___ nucleases D. fatty acids and glycerol

7. Based on experiments, what is the effect of extremeconditions of pH and temperature (boiling tube) on enzymeactivity?

8. ATP stores energy in the form of___

___ Chemical energy

___ Kinetic energy

___ Thermal energy

___ Activation energy

9. An allosteric site in anenzyme is____

__ the site where reactions occur

__ the site that binds aregulator

__ the site that binds thesubstrate

__ the site that binds the product

10. Enzymes increase the rate of reactions by making thetransition state less stable.
__ True

__ False

11. Enzymes increase the rate of reactions by placing reactingparts of the molecule in favorable positions.
__ True
__ False

12. Which of the followingis a mechanism for regulation of enzymes?

__ covalent modification

__ feedback inhibition

__ allosteric regulation

__ all of the above

13. Which of the following represents a correct order of eventsin an enzyme catalytic cycle?

1.enzyme changes shape

2.substrate binds to active site

3.substrate is converted to products

4. products are released from activesite

__ 1>2>3>4

__ 2>1>3>4

__ 3>2>1>4

__ 2>4>3>1

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