levo

Microbiology

Growth requirements and growth inhibition

  • 3 things to know
  • A2 6

Overview

Nutrients, oxygen, temperature, light, pH and surfaces, inhibition by osmotic potential, irradiation, antibiotics, antifungals and antivirals, zones of inhibition and comparing growth monitoring methods.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What nutrients do bacteria and fungi need to grow?

Key term

How does oxygen availability affect microbial growth?

Key term

How does temperature affect microbial growth?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What nutrients do bacteria and fungi need to grow?

    Model answer

    Bacteria and fungi need a carbon source such as glucose and a nitrogen source for proteins. Minerals, water and sometimes vitamins are also needed.

  2. 2

    How does oxygen availability affect microbial growth?

    Model answer

    Aerobes grow only with oxygen, and obligate anaerobes are killed by it. Facultative anaerobes grow in either condition.

  3. 3

    How does temperature affect microbial growth?

    Model answer

    Growth is fastest at an optimum temperature, which is about 37 °C for many human pathogens. High temperatures denature enzymes, and low temperatures slow growth.

  4. 4

    Why does light matter for some microorganisms but not others?

    Model answer

    Photosynthetic microorganisms, such as algae and cyanobacteria, need light to make food. Most bacteria and fungi grow without light.

  5. 5

    How does pH affect the growth of bacteria and fungi?

    Model answer

    Most bacteria grow best near neutral pH. Many fungi prefer slightly acidic conditions, which is why fruit and bread go mouldy.

  6. 6

    Why do growth surfaces matter to microorganisms?

    Model answer

    Many microorganisms attach to surfaces and form biofilms. Biofilms on medical devices such as catheters resist antibiotics and are hard to remove.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Experimental Techniques
Human Body Systems
Physical Chemistry in Industrial Processes
Brain Science

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

One cubic equals 1000 cm³.
decimetremetrecentimetre

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AThe energy of all bonds broken is added up.
BThe energy of all bonds formed is subtracted.
CA negative answer shows an exothermic reaction.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Acidosis means blood pH falling below 7.35.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Microbiology, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.