Microbology

Question 1

Micro organisms

Answer 1

We have more of these than any other cell types in our body

Survive in extremes

Question 2

Micro organisms are universal

Answer 2

Survive in extremes

Some organisms able to make spores

Involved in producing medicines, and vitamins

Destroy rubbish

Make cheese, wine

Colonise our surfaces

Regulate immunity

Question 3

Bacteria

Answer 3

Prokaryotes

Tend to be larger, and classed according to shape
Cocci round
Rod oval
Spiral curved

Have two names escherichia coli

Question 4

Bacterial cell wall

Answer 4

Gram positive bacteria have a thicker cell wall, and take up gram stain > purple

Gram negative organisms have a thinner wall, and not to take up gram stain > red

Question 5

Viruses

Answer 5

Classed as DNA, RND or retroviruses

Genetic material protected by envelope

Enter host cell, and take over functioning, release viral proteins, finally destroy cell.

Cause AIDS, common cold, rabies, chicken pox, small pox, herpes and come cancers.

Question 6

Types of outbreak

Answer 6

Sporadic

Endemic

Epidemic

Pandemic

Healthy protection agency CDC

Question 7

Virulence and pathogenicity

Answer 7

Virulence is the power of an organism to overcome host defences and to produce disease

ID 50
LD 50

Pathogenicity is the ability to make one Ill

Question 8

Portal of entry

Answer 8

Mucous membrane of respiratory or GI tract

Skin

Parental route

Question 9

Adherence

Answer 9

Most organisms need to adhere to host tissue, adh sin or Luganda on surface of cell, often on pili or flagella

most are glycoproteins or lipoproteins

bind to specific receptors on host, most are sugar

Question 10

Enzymes

Answer 10

Some organisms can increase virulence by releasing extra cellular enzymes
Coagulates
Kinases
Hyaluronidase breaks down hyaluronic acid
Collagenase
IgA protease

Question 11

Antigenic variation

Answer 11

Alter surface antigens, often by altering gene expression

Question 12

Bacterial damage to host cell 1

Answer 12

Using host nutrients
Iron needed by most bacteria, but is tightly bound to transport proteins so bacteria sidrephore

Cell unable to use iron, that may be even be toxic

Question 13

Bacterial damage to host cell 2

Answer 13

Direct damage

Host cell usually rupture, releasing pathogen and also including inflammatory response

Question 14

Bacterial damage to host cell 3

Answer 14

Production of toxins> fever, CVS disturbance, diarrhoea, shock, inhibition protein synthesis, destroy blood vessels and cells, destroy nervous system > spasms

May be exotoxins or endotoxins

Question 15

Bacterial damage to host cell 4

Answer 15

Hypersensitivity reactions

Question 16

Pathogenic properties of viruses 1

Answer 16

Cytopathic effects
Prevent production of macromolecules 
Cell release lysosomes 
Inclusion bodies
Antigenic changes 
Infected cells adjacent to each other fuse to form giant cell, called syncitium 
Protection of interferons
Chromasomal change in host cell, oncogenes can be activated 
Contact inhibition may be over ridden

Question 17

The study of micro organisms

Answer 17

Includes

Bacteriology - bacteria
Virology - viruses
Mycology- fungi
Protozoology- protozoa

Question 18

Microorganisms

Answer 18

Little creatures

Organisms too small to be seen with a naked eye

Eukaryotes

Prokaryotes

Question 19

Different types of bacteria

Answer 19

Coccus

Diplococcus

Staphylococcus

Streptococcus

Bacillus

Vibrio

Spirichaetes

Question 20

Structure of typical bacteria

Answer 20

Capsule

Cell wall

Pilli

Question 21

Factors necessary for bacterial growth

Answer 21

Nutrition such as proteins and carbohydrates

Water

Temperature

PH

Oxygen

Aerobic

Anaerobic organisms

Question 22

Binary fission

Answer 22

Where the DNA replicates

Splits into two

Cell separation

Question 23

The four phases in the culture of bacterial growth curve

Answer 23

Lag

Log

Stationary

Death

Question 24

Lag phase

Answer 24

Bacteria starts to adapt the new environmental conditions

There is a lot of metabolic activity

Little or no bacteria division takes places

Question 25

Log phase

Answer 25

Exponential growth phase

Bacteria population increases rapidly

Conditions are optimum growth

Question 26

Stationary phase

Answer 26

With the exhaustion of nurtrients and accumulation of secondary metabolic production, growth rate slows

The growth rate equals the death rate

Question 27

Death phase

Answer 27

Bacteria growth decreased with time due to lack of nutrients and toxic metabolic by- products

Bacteria death is greater than production of new ones