Introduction to Bacteria (H&D 004)

Question 1

What is the definition of microbiology

Answer 1

Study of small organisms that are invisible to the naked eye

Question 2

What are organisms that are studied in microbiology

Answer 2

Fungi, algae, protozoa, bacteria and virus

Question 3

What are the three domains of a microorganism

Answer 3

Eukarya, Archaea and Bacteria

Question 4

What are the three common shapes of bacteria cells

Answer 4

cocci (spherical), bacilli (rod-shaped) and spiral (spirillum)

Question 5

What does it mean if bacteria are gram positive

Answer 5

Their cell wall consists of thick peptidoglycan hence will have no outer-lipid membrane

Question 6

What does it mean if bacteria are gram negative

Answer 6

Their cell wall has a thin peptidoglycan in which will have a outer-lipid membrane

Question 7

How is the capsule a virulence factor for the bacteria

Answer 7

Prevents the bacteria from experiencing desiccation, allowing the bacteria to multiply and survive longer

Question 8

How is the flagellum a virulence factor for the bacteria

Answer 8

Allows the movement of the bacteria to move and divide from one place to another

Question 9

How is the pili a virulence factor for the bacteria

Answer 9

Allows attachment to the host cell enabling itself to multiply

Question 10

What is the definition of the ‘infectious dose”

Answer 10

The number of bacteria able to cause an infection

Question 11

What are plasmids of the bacteria

Answer 11

Extra chromosomal elements in which code for traits like toxin production and drug resistance

Question 12

What are endospore of the bacteria

Answer 12

Structure that helps bacteria survive heat, cold, chemicals, desiccation and lack of nutrients. However, not all bacteria have this structure

Question 13

What is the definition of colonization

Answer 13

When bacteria penetrate and grow within the tissue

Question 14

What contributions enable the process of colonization to occur

Answer 14

Must have appropriate amount of nutrients and environmental conditions as well as exo-enzymes

Question 15

What is the function of exo-enzymes

Answer 15

Cell and tissue destruction

Question 16

What are two ways that bacteria are able to cause disease

Answer 16

Invasiveness and toxigenicity

Question 17

What is the definition of invasiveness

Answer 17

Rapid bacteria growth in tissue and organs before immune defenses can develop (eg. tuberculosis and rheumatic fever)

Question 18

What is the definition of toxigenicity

Answer 18

Toxin production by bacteria in which is transported to tissues or organs in the body. Exotoxins are substances that are produced and then secreted outside of the bacterium and endotoxins are toxins that are released in the cell wall of the bacterium (eg. release of exotoxins cause cholera (permeability in the gut) and tetanus (affects muscle function)

Question 19

What is the definition of microbiota

Answer 19

An ecological community of microorganisms that share human body space (Also known as normal flora)

Question 20

What are the two types of normal flora

Answer 20

Resident flora and transient flora

Question 21

What is the definition of resident flora

Answer 21

Microorganisms that are permanently with the body

Question 22

What is the definition of transient flora

Answer 22

Microorganisms that are picked up from the environment (eg. soil when gardening working with patients in the hospital)

Question 23

Why would it be bad to be a transient flora

Answer 23

Because some microorganisms that are picked up by the environment might be infectious. This may result in some people becoming a contact or asymptomatic carrier

Question 24

Why would having a normal flora be better for the human host

Answer 24

Prevention of other organisms from being established and causing an infection

Question 25

What are some examples of a normal flora preventing pathogens

Answer 25

Bacteria in the lining of intestines to prevent attachment of pathogens to the lining, or bacterium controlling the growth of potential pathogens via secretion of anti-microbial substances