1. Prokaryotes & Viruses

Question 1

when were prokaryotic cells developed

Answer 1

3.5bn yrs ago

Question 2

what are the two domains of bacteria

Answer 2

archea and bacteria

Question 3

where do archea bacteria often live

Answer 3

extreme environments (extremophiles)

Question 4

name two differences between archea and bacteria

Answer 4

1. archea have introns in their genes, bacteria do not

2. archea have histones- bacteria do not

Question 5

what 2 words describe the shape of prokaryotes

Answer 5

cocci (spherical)

bacilli (rod shape)

Question 6

what protein is the flagella composed of

Answer 6

flagellin- this is a motor which drives the flagella

Question 7

what is the most abundant organelle found in the cytoplasm

Answer 7

ribosomes

Question 8

what aids prokaryote binding to substrate?

what is the comprised of?

Answer 8

pili- composed of pilin

Question 9

describe DNA presentation in prokaryotes

Answer 9

loops of circular DNA called plasmids

no nuclear membrane

Question 10

what is found in the infoldings of the plasma membrane in prokaryotes
give an example

Answer 10

enzymes

e.g. stromatolites contain enzymes that facilitate photosynthesis

Question 11

what drives the flagellum

Answer 11

a proton gradient, protons pass through the rotary motor causing the motor to spin

Question 12

what drives the proton gradient driving the flagella

Answer 12

the cell itself- plasma membrane hydrogen ion pump pumps h+ out of the cell using ATP

Question 13

what organelle facilitates DNA plasmid sharing between prokaryotes

Answer 13

a special pili

Question 14

What are the two types of prokaryote cell walls

Answer 14

gram positive & gram negative

Question 15

describe gram positive and an associated disease

Answer 15

thick 40nm peptidoglycan layer

pneumonia

Question 16

describe gram negative and an associated disease

Answer 16

complex cell wall structure (makes them more dangerous)

Black Death

Question 17

what are the 4 prokaryotic modes of nutrition

Answer 17

photoautotroph
chemoautotroph
photoheterotroph
chemoheterotroph

Question 18

describe photoautotrophs

Answer 18

use light energy to synthesis organic compounds from carbon dioxide

Question 19

describe chemoautotrophs

Answer 19

use CO2 and obtain energy by oxidising inorganic substances

Question 20

describe photoheterotrophs

Answer 20

use light to generate ATP but obtain carbon in an organic form

Question 21

describe chemoheterotrophs

Answer 21

use organic molecules to supply both carbon and energy

Question 22

true or false:

viruses are alive

Answer 22

false- cannot be considered to be alive as they do not self repair or have an energy transduction system

Question 23

what microscope identifies viruses

Answer 23

electron microscopess

Question 24

what are the 4 types of viruses

Answer 24

• filamentous viruses- nucleic acid is arranged in a helix stabilised by protein sub-units
• spheroid viruses- nucleic acid inside a protein envelope
• tailed spheroid viruses- (above with a tail)
• enveloped viruses- lipid envelopes, e.g. corona

Question 25

what is the name for the virus’ protein coat, what is it made from

Answer 25

1) capsid

2) capsomers

Question 26

what is the name for a viral particle

Answer 26

a viron