The Good, Bad, Ugly of Bact

Question 1

What is nitrogen fixation

Answer 1

The process by which molecular nitrogen is reduced to form ammonia

Question 2

What in the body are usually free of microorganisms

Answer 2

Internal tissues - blood, brain, muscle etc

Question 3

How many bacteria does the normal human flora contain

Answer 3

More than 200

Question 4

What does the normal flora gain from the human host

Answer 4

• Supply of nutrients
• Stable environment
• Constant temp
• Protection
• Transport

Question 5

What does the human host gain from the normal flora

Answer 5

• Nutritional benefits
• Stimulation of immune system
• Colonization strategies that exclude potential pathogens at the site
• (E. coli in human colon synthesises vit B & releases it for human use)

Question 6

Homofermentors

Answer 6

Single product - lactic acid

Question 7

Heterofermentors

Answer 7

Multiple products - - lactic acid, ethanol, CO2

Question 8

What is bioremediation

Answer 8

Any process that uses microorganisms, fungi, green plants or their enzymes to return the environment altered by contaminants to its original condition
(Bacteria used to break down sewage wastes)

Question 9

Biotechnology definition and examples

Answer 9

Defined as the application of organisms such as bacteria, fungi, algae to the manufacturing & services industries
* Fermentation processes - Lactobacillus used in prep of fermented foods
* Chemical manufacturing - ethanol, acetone, organic acid
* Pharmaceuticals - antibiotics, vaccines
* Energy - biogas
* Food products - dairy products, amino acids & proteins

Question 10

How are genes introduced into the host in genetic engineering

Answer 10

By means of a carries (vector)

Question 11

HOw does genetic engineering work

Answer 11

• Genes introduced into host by means of a vector
• Foreign DNA becomes permanent feature of host, being replicated & passed on to daughter cells
• Bacterial cells transformed & used in production of important products
• Can be engineered to produce insulin, growth factors, antibodies

Question 12

Decomposition: what is autolysis

Answer 12

The breaking down of tissues by the bodys own internal chemicals and enzymes

Question 13

Decompostion: what is putrefaction

Answer 13

The breakdown of tissues by bacteria

Question 14

Opportunistic pathogens

Answer 14

Cause damage when immune system is breached

Question 15

What bacteria causes tooth decay

Answer 15

Streptococcus mutans

Question 16

Where is S. aureus present in 30% of population

Answer 16

Nasal passages

Question 17

When can S. aureus causes serious infection

Answer 17

When innate immune system is breached

Question 18

Function of biofilm

Answer 18

• Protects bacteria from washing away
• Slime protects from antibiotic & immune system

Question 19

What can invasive streptococcal infections develop into

Answer 19

Necrotising faciitis (flesh-eating bacteria)

Question 20

Toxin that causes botulism

Answer 20

Clostridium botulinium

Question 21

What does Clostridium botulinium do

Answer 21

Bonds to presynaptic stimulatory terminals & blocks the release of neurotransmeitter acetylcholine - required for a nerve to stimulate the muscle

Question 22

Clinical symptoms of botulism

Answer 22

• Weakness
• Dizziness
• Dryness of mouth
• Nausea & vomiting
• Neurologic features - blurred vision, inability to swallow, difficulty in speech

Question 23

What is the botulism toxin specific for

Answer 23

For peripheral nerve endings at the point where a motor neuron stimulates a muscle

Question 24

Epidemiology

Answer 24

The study of factors affecting health & illness of populations. (outbreak investigation, study design, analysis, test hypotheses)