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Flashcards in Introduction to microbiology Deck (55)
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1

define akaryote

no nucleus

2

define prokaryote

single cell nucleus lacking membrane bound nucleus.

3

define eukaryote

all other cells with nuclei

4

what percentage of cells in the human body are of human origin

10%

5

what type of organism do most microbiota in the human body consist of

bacteria.

6

what organism is commonly found on the hard surface of teeth

streptococcus mutans

7

what organism is commonly found on the soft tissues of the mouth

streptococcus salivarius

8

what vitamin do the bacteria of the gut provide us with

vitamin K.

9

what chemical/ element required for life is produced by bacteria of the body

nitrogen.

10

what term is used to describe bacteria which cause disease

pathogenic or virulence

11

do all bacteria in the body cause harm

No.

12

what is used to identify or determine whether an organism causes disease or not.

Koch's postulates.

13

what is stated in koch's postulates (4 points) for an organism

The causative organism must be isolated from every individual suffering from the disease in question.
The causative organism must be cultivated artificially in pure culture.
When the causative organism is inoculated from pure culture, the typical symptoms of the infection must result.
The causative organism must be recoverable from individuals who are infected experimentally

14

what is stated in koch's postulates for virulent genes. (6 factors)

The gene encoding the trait of interest should be present and transcribed/translated in a virulent strain.
the gene encoding the trait of interest should NOT be present or should be silent in a strain that does not cause disease;
disruption of the gene in a virulent strain should result in the formation of a strain that is incapable of casing disease;
introduction of the gene into a strain that previously did not cause disease should transform the strain into one that does cause disease;
the gene must be expressed during infection;
antibodies raised against the gene product
or the appropriate cell-mediated immunity
should protect experimental subjects
against disease.

15

what are the main issues with Koch's postulates

difficulty of isolation the causative agent.
impossible to grow some
ethical objections

16

what is the basic structure of a virus

nuclei acid core with a protein coat.
some may have an envelope.

17

are viruses intracellular or exracellular.

Viruses are obligate intracellular parasites.

18

how do reteroviruses cause disease.

Retroviruses are unusual in that the virion carries an RNA copy of the genome but upon infection of a host cell a cDNA copy of the virus genome is made using the enzyme reverse transcriptase and put into the human genome.

19

what organism causes plant infections

Viroids.

20

what organism is spongiform encephalopathies classed as

prion

21

define viroids

naked, infectious RNA molecules that are not associated with any proteins.

22

are fungi, prokaryotic, eukaryotic or akaryotic.

eukaryotic

23

what is the cell wall of fungi made from

chitin- polymer of N-acetyl glucosamine

24

define moulds

a type of fungi that grow in mats of tiny filaments known as hyphae that form mats called mycelia.

25

are moulds multicellular or unicellular

muulticellular

26

are yeasts multicellular or unicellular

unicellular

27

what is the most common yeast infection

thrush" caused by Candida albicans.

28

what is the most common mould infection

superficial infections such as ringworm and athlete's foot.

29

Are protista eukaryotes, prokaryotes or akaryotes

eukaryotes

30

what are the 4 classes of protista.

1. apicomplxa (formerly sporozoa),
2. flagellate protista,
3. ciliate protista and
4. amoebae.