Prokaryotic Cells

Question 1

Do bacterial cells have cell walls?

Answer 1

Yes, all bacterial cells have cell walls

Question 2

Are the contents of bacterial cells hypertonic or hypotonic to the surrounding medium?

Answer 2

Hypertonic so water moves into the cell by osmosis and the cell wall stopps it from bursting

Question 3

What is a feature of all bacterial cell walls?

Answer 3

A layer of peptidoglycan made up of many paralell chains with short peptide cross links

Question 4

What is a capsule?

Answer 4

A slime layer around cells that prevents them from being consumed in phagocytosis

Question 5

What are pilli?

Answer 5

Thread-like protein projections found on the surface of some bacteria

Question 6

What are flangella?

Answer 6

Proteins on the outside of the cell that move it around through rapid rotations

Question 7

What is the difference between the cell membrane in eukaryotic and prokaryotic cells?

Answer 7

Eurakyotic cells have mitochondria but in prokaryotic cells the membrane has some respiratory enzymes

Question 8

What are mesosomes?

Answer 8

Infoldings of the bacterial cell membrane

Question 9

What are plasmids?

Answer 9

Circles of DNA that can reproduce independently of the cell

Question 10

What kind of ribosomes are found?

Answer 10

70s

Question 11

What is the purpose of gram-staining?

Answer 11

To distinguish between gram-positive and gram-negative bacteria

Question 12

What is the difference between gram positive and gram negative bacteria?

Answer 12

In the cell wall
Gram positive has a think layer of peptidoglycan
Gram negative has a thin layer without teichoic acid and an outer layer of lipopolycaccharides

Question 13

What colour are gram positive bacteria after gram staining?

Answer 13

Violet

Question 14

What colour are gram negative bacteria after gram staining?

Answer 14

Red

Question 15

Why is it important to know if a bacteria is gram positive or gram negative?

Answer 15

Different antibiotics only work on specific cell walls

Question 16

What is a virus?

Answer 16

An intracellular paracite that reproduces in the cells of other living organisms

Question 17

How do viruses attatch to their host cells?

Answer 17

Antigens that target proteins in the host cell surface membranes

Question 18

What are the three types of virus?

Answer 18

DNA viruses
RNA viruses
RNA reteroviruses

Question 19

What is a DNA reterovirus?

Answer 19

Where viral DNA acts directly as a template for both new DNA and the synthesis of viral proteins.

Question 20

What are some examples of DNA reteroviruses?

Answer 20

Small pox

Lamdaphage

Question 21

What is an RNA virus?

Answer 21

They have RNA as 70% of their genetic material and are more likely to mutate
Don’t produce viral DNA.

Question 22

What is an ssRNA virus?

Answer 22

RNA viruses that contain a single strand of RNA

Question 23

What is a positive ssRNA virus?

Answer 23

RNA can act directly as mRNA and can be translated at the ribosomes

Question 24

What are some examples of positive ssRNA viruses?

Answer 24

Polio

Hep C

Question 25

What is a negative ssRNA virus?

Answer 25

The RNA must be transcribed before it is translated

Question 26

What are some examples of negative ssRNA viruses?

Answer 26

Influenza Ebola Measles

Question 27

What is a RNA reterovirus?

Answer 27

They have a protein capsid and lipid envelope. The RNA strand makes reverse transcriptase so makes DNA with the viral genome that can be incorperated into host DNA.

Question 28

When a virus is inside the cell, what are the two routes to infection?

Answer 28

Lysogenic pathway | Lytic pathway

Question 29

What is the lysogenic pathway of viral infection?

Answer 29

They don't cause disease at first and they insert themselves into host DNA

Question 30

What is the lytic pathway of viral infection?

Answer 30

Viral DNA is replicated independantly of the host cell and the cell then bursts with viral DNA and produces symptoms

Question 31

How do positive ssRNA viruses replicate?

Answer 31

The strand of RNA is used directly as the sense strand of mRNA and is translated into viral proteins

Question 32

How do negative ssRNA viruses replicate?

Answer 32

The viral RNA must be transcribed onto a sense strand by using RNA replicase and then coding for viral proteins

Question 33

How do RNA reteroviruses replicate?

Answer 33

Translated into DNA by viral enzyme and inserted into host DNA

Question 34

What ways do antivirals work?

Answer 34

They target the receptors of the virus that recognise host cells They target the enzymes that help to translate or replicate DNA or RNA They inhibit protease enzymes

Question 35

When there is an epidemic, who are the first people to be vaccinated?

Answer 35

Health care workers Children The elderly

Question 36

What are the ways to control the spread of disease?

Answer 36

``` Rapid identification Nursing in iscolation Preventing transmission Steralising and disposing of equiptment after use Wearing protective clothing ```

Question 37

What phases must drugs do through before being put on the market?

Answer 37

Early research Pre-clinical testing Clinical trials Regulatory review

Question 38

What are the considerations when fast-tracking vaccines through clinical testing?

Answer 38

Severity of the disease Avaliability of other treatments Effectiveness of disease control Freedom over participation

Question 39

What are the reasons against using untested drugs?

Answer 39

Not ethical May make the situation worse if side effects Difficult to decide who gets the drug Informed consent could be an issue