Good & Bad of Bacteria

Question 1

What bacteria causes botulism

Answer 1

Clostridium botulinum

Question 2

Explain how Clostridium botulinum works?

Answer 2

Toxin binds to presynaptic stimulatory terminal - blocks the release of neurotransmitter acetylcholine (needed for muscle stimulation) - 18-36 hours for symptoms to begin- weakness, dizziness, dryness of mouth - flaccid paralysis e.g. difficulty swallowing, speaking, descending weakness in skeletal muscle

Question 3

What bacteria causes tetanus

Answer 3

Clostridium tetani

Question 4

Explain the toxin produced by Clostridium tetani?

Answer 4

Similiar structure to C. botulinum toxin - different target cells - static paralysis - tetanospasmin shows tropism for inhibitory motor neurons of the CNS

Question 5

What bacteria causes Chloera?

Answer 5

Vibrio Cholerae

Question 6

What is a cholera cot?

Answer 6

Plastic cot with a hole leading to a collection bucket - keeps patient, cot, & clinic clean

Question 7

What science was established to determine the cause of cholera?

Answer 7

Epidemiology by John Snow in 1849 - traced the cause of an outbreak in Soho to one pump - water-born not air-born

Question 8

What science was established to determine the cause of cholera?

Answer 8

Epidemiology by John Snow in 1849 - traced the cause of an outbreak in Soho to one pump - water-born not air-born

Question 9

What is Epidemiology?

Answer 9

Study of the factors affecting the health & illness of a population - logic behind interventions for public health & preventive medicine - outbreak investigation, study design, data collection & analysis

Question 10

What causes necrotising fascitis?

Answer 10

Group A Streptococci

Question 11

Explain a Group A Streptococcus infection?

Answer 11

Exposed mucous membrane(skin lesions) - necrotising fascitis - skin must be removed and replaced by skin graft

Question 12

What is a Biofilm?

Answer 12

Some bacteria produce an organic polymer matrix & become embedded in it - protects from being washed away or attacked by immune cells or antibiotics - catheter sites

Question 13

What bacteria causes TB

Answer 13

Mycobacterium tuberculosis

Question 14

Explain TB infection

Answer 14

Chronic bacterial infection - spread through air - usually affects lungs - 2 billion infected - 8 million develop it each year - 3 million die - affects people with weakened immune system (HIV, AIDS) - immune response causes damage - steroids to reduce inflammation

Question 15

What are opportunistic pathogens?

Answer 15

Part of the normal microbiome that causes diseases when the immune system is compromised

Question 16

What is the most common bacteria that causes tooth decay?

Answer 16

Streptococcus mutans

Question 17

Name 2 opportunistic pathogens

Answer 17

Streptococcus mutans - tooth decay
Staphylococcus aureus - boils & abscess

Question 18

How does S. mutans cause tooth decay?

Answer 18

High sugar diet - food - bacterial growth = plaque - metabolises sugars & excretes acid - wear down enamel

Question 19

Explain S. aureus

Answer 19

Lives in nasal cavity of 30% population - cause serious infection (skin)

Question 20

What virus causes COVID-19

Answer 20

SARS-CoV-2 (severe acute respiratory system coronavirus-2)

Question 21

Explain the 2 types of decomposition

Answer 21

Autolysis - breakdown by body’s own chemicals & enzymes
Putrefaction - breakdown by bacteria
Occurs at the time of death - release gas & body swells

Question 22

Name 2 bacteria that can be used as pesticides?

Answer 22

Bacillus thuringienesis - Gram positive, soil dwelling - produces BT toxin - Lepidopteran-specifc insecticide
Pseudomonas fluorescens - produces anti-fungal compound - protect sugar beet

Question 23

What are the benefits of bacterial pesticides over chemical pesticides?

Answer 23

More specific, less harmful to environment, die off after food source is gone

Question 24

What is bioremediation?

Answer 24

Processes using microorganisms, fungi, green plants, & enzymes to return the environment altered by contaminants to its original condition

Question 25

2 specific examples of bacteria used in bioremediation

Answer 25

Deinococcus radiodurans - most radioresistant organism - consume & digest toluene & ionic mercury from radioactive nuclear waste
Pseudomonas putida - break down xylene & camphor

Question 26

Use of bioremediation example

Answer 26

Cleaning chlorinated hydrocarbons from oil spils in soil & groundwater - nitrate & sulphate fertilisers added help indigenous or exogenous bacteria - can reach areas with excavation - cheaper than ex situ treatment e.g. incineration

Aerobic & anaerobic bacteria in sewage treatment - break down organic material to harmless soluble sludge in settling tanks - produce methane used for energy

Question 27

What is biotechnology?

Answer 27

Application of bacteria, fungi, algae, etc. to manufacturing & services industey

Question 28

What bacteria are used for fermentation?

Answer 28

Lactobacilli

Question 29

Explain the differnece between heterofermentous & homofermentous lactobacilli?

Answer 29

Heterofermentous - lactic acid, ethanol, CO2
Homofermentous - lactic acid

Question 30

Explain lactobacilli?

Answer 30

Gram + aerotolerant anaerobes - complex nutrition - uses sugar as a food source - L. delbrueckii & L. acidophilus (yogurt) - S. bovis produce polylactic acid - sauerkraut, pickles, some fermented meats

Question 31

Explain normal flora/microbiota?

Answer 31

Internal tissue is m/o free (blood, brain, muscle) - surface tissue (skin & mucous membranes) colonised by 200 m/o species, mostly mutualistic, bacteria gain nutrients, stable environment, constant temperature, protection, stimulation of immune system, exclude potential pathogens

Question 32

Explain some opportunistic pathogens?

Answer 32

Escherichia coli in colon usually synthesises Vitamin B - cause infection
Candida infections in vaginal tract (thrush)

Question 33

What allows opportunistic pathogens to cause disease?

Answer 33

Antibiotic treatment, immunocompromised

Question 34

Explain nitrogen’s role in biology?

Answer 34

Most abundant element in the atmosphere - vital element - amino acids, proteins, vitamins, & nucleic acid - primary nutrient of green plants (modified before being used by living systems)

Question 35

Explain nitrogen fixation?

Answer 35

Molecular nitrogen reduced to form ammonia N2 > NH3 - 85% biological, 13% industrial - Rhizobium & Bradyrhizobium in agriculture

Question 36

Explain the symbiotic relationship in

Answer 36

Mutually beneficial - legume plants (alfalfa, white clover) & rhizobia bacteria - gives nitrogen to plant as ammonium - legume provides carbohydrates to bacteria - increases soil fertility