100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Chapter 6-Microbiology Questions and Answers 100% Accurate $13.49   Add to cart

Exam (elaborations)

Chapter 6-Microbiology Questions and Answers 100% Accurate

 1 view  0 purchase
  • Course
  • Microbiology
  • Institution
  • Microbiology

Chapter 6-Microbiology

Preview 2 out of 10  pages

  • November 1, 2024
  • 10
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers
  • Microbiology
  • Microbiology
avatar-seller
julianah420
Chapter 6-Microbiology

What are the physical requirements for microbial growth? - answer Temperature, pH,
and osmotic pressure

Temperature - answer Most microorganisms grow well at the temperatures that humans
favor; but there are three major ranges of temperature: psychrophile’s, mesophiles,
thermophiles

psychrophile’s - answer cold-loving microbes (-10 to 20)

Mesophiles - answer moderate-temperature loving microbes (10 to 50)

Thermophiles - answer heat loving microbes (40 to 73)

Maximum growth temperature - answer highest temperature at which growth is possible

optimum growth temperature - answer temperature at which the species grows back

minimum growth temperature - answer lowest temperature at which the species will
grow

Typically the max and min growth temperatures are only about 30 degrees Celsius
apart

psychotrophs - answerfood microbiologists favor, this group is known for spoilage of
food

Why refrigerate? - answerbased on the principle that microbial reproduction rates
decrease at low temperatures (or entirely dormant)

hyperthermophiles or extreme thermophiles - answerarcahe; have an optimum growht
temperature of 80* C or more; live in hot springs and sulfur important in their metabolic
activity

What pH do bacteria typically grow in? - answerneutrality (between 6.5 adn 7.5)
Cutlured bacteria often produce acids that eventualy interfere with their own growth;
chemical buffers must be included in growth medium

acidophiles - answerremarkably tolerant of acidity

How do most microorganisms obtain all their nutrients? - answerthrough solution from
their surrounding water; thus they require water for growth;

, How does high osmotic pressure effect bacteria? - answerWhen concentration of
solutes is higher in the cell (hypertonic)

When concentration of solutes is higher outside the cell - answerCell will shrink,
removes necessary water

Plasmolysis - answershrinkage of the cell cytoplasm
Plasma membrane pulls away from the cell wall; addition of salts to a solution will
increase osmotic pressure (can be used for food preservation)

Extreme Halophiles - answeradapted well to high salt concentrations that they actually
require them for growth

Obligate halophiles - answerrequire salt for growth

Facultative halophiles - answerdo not require high salt concentrations but are able to
grow in salt concentrations up to 2%; few can tolerate even up to 15%

Typical medium composed of? - answer1.5% agar, the rest is water!; if all water, the
enviornment is hypotonic, water will move into the cell-lyses

What are the chemical requirements of microbial growth? - answercarbon, nitrogen,
suflur, phosphorus, trace elements, oxygen, and organic growth factors

Why carbon? - answerone of the most important requirements for microbial growth;
carbon is the structural backbone of living matter; it is neeed for all organic ompounds
that make up a living cell; half of the dry weight of a living cell is carbon

Chemoheterotrophs - answerget most of their carbon from the source of their energy

Nitrogen, sulfur, phosphorus - answerDNA and RNA and ATP synthesis: require
nitrogen and phosphorous
Protein synthesis: requires considerable amounts of nitrogen and some sulfur

Nitrogen 14% of dry weight; phosphours and sulfur 4%

What is nitrogen used for? - answerprimarily to form the amino group of the amino acids
for proteins

Nitrogen fixation - answeruses gaseous nitrogen N2 directly from the atmosphere

Other ways to get nitrogen: decomposing protein-containing material or NH4+
(ammonium ions), or nitrates

Source of sulfur - answerUsed to synthesize suflur-containing amino acids and vitamins

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller julianah420. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $13.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

85169 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$13.49
  • (0)
  Add to cart