Prokaryotes (flashcardable)

Question 1

Why is it important to know about prokaryotes?

Answer 1

Food
Agriculture
Disease
Energy/environment
Biotechnology

Question 2

Use of prokaryotes and food

Answer 2

• preservation (find ideal enviro)
• fermentation e.g. beer and yeast
• food preparation (being more hygienic)

Question 3

Use of prokaryotes and agriculture

Answer 3

• nitrogen fixation e.g. rhizobium and legumes
• nutrient cycling
• animal husbandry e.g. digestion of cellulose in animals

Question 4

Use of prokaryotes and disease

Answer 4

• better hygiene

- vaccines and antibiotics

Question 5

Use of prokaryotes and energy/environment

Answer 5

• methanogenic bacteria
  produce methane and harvest light energy
• microbial biomass and existing waste to create biofuel

Question 6

Use of prokaryotes and biotechnology

Answer 6

• gm organisms

- producing pharmaceutical and therapeutic chemicals

Question 7

Prokaryotic cell shape and affect of SA

Answer 7

• diameter of 1um and length of 2 - 50um
• SA limiting factor: diffusion and also increasing SA ration generates larger population = more mutations and therefore faster evolution (also haploid) so adapt quickly

Question 8

How bacterial membrane lipids are different from eukaryotic lipid membranes

Answer 8

• bacteria can be saturated or monounsaturated vs eukaryotic is polyunsaturated
• bacteria have no sterols

Question 9

What affects the fluidity of bacterial membrane

Answer 9

• temperature: higher temperature is more fluid and lipids can move around
• longer chains (more carbon) make it more stable
• is important as prokaryotes cant control their own environment so must be able to adapt

Question 10

What are the different transport systems in the bacterial membrane

Answer 10

Simple system
Group translocation
ABC system

Question 11

Simple system of transport

Answer 11

Driven by energy in proton motive force

Question 12

Group translocation transport

Answer 12

Chemical modification (phosphorylation) of transported substance 
( driven by phosphoenolpyruvate)

Question 13

ABC system of transport

Answer 13

Periplasmic binding proteins involved

Energy generated by ATP breakdown

Question 14

Role of the cell membrane

Answer 14

• permeability barrier
• protein anchor
• energy production and conservation

Question 15

Gram neg

Answer 15

• folded cell membrane
• peptidoglycan cell wall with periplasm and 2 membranes
• 2nd membrane contains lipopolysaccharide complex

Question 16

Gram pos

Answer 16

• peptidoglycan wall

- techoic acid (slight neg charge helps bind cell wall and membrane)

Question 17

Lipopolysaccharide complex

Answer 17

Polysaccharides (core and O) and A lipid

Associates to several proteins to form membrane and replaces the phospholipids

Question 18

Peptidoglycan

Answer 18

Only in bacterial cells
Repeating nag and nam sugar derivatives with amino acids
Glycosidic bonds
Amino acids form tetrapeptide bonds between chains = rigidity

(Archaeal pseudo peptidoglycan = nag and Nat)

Question 19

Prokaryotes vs eukaryote DNA

Answer 19

Pro = haploid vs eu = diploid 
Pro = genome looped and not surrounded by nucleus 
Pro= no nuclear membrane and no simultaneous transcription and translation 
Pro = no proteins for dna packaging

Question 20

Plasmids

Answer 20

Circular dna containing genes with special properties e.g anti bac resistance
Helps evolution and can have multiple in a bacteria
Useful for biotech

Question 21

Fimbriae

Answer 21

Enables organisms to stick to cells surface and form biofilms on surfaces

Question 22

Pilli

Answer 22

Used for conjugation (genetic exchange)

Question 23

Peritrichous = flagella

Answer 23

Flagella all the way around the cell

Move via spiralling

Question 24

Polar flagella

Answer 24

At one end

Move via whipping

Question 25

Lophotrichous

Answer 25

Mutliple at one end | Move via whipping

Question 26

Structure of a flagellum

Answer 26

Helical and constant length between curves (like wavelengths) Grows from base and breaks if too long L and P ring fixes in place MS and C ring twists Fli proteins cause rotation (electrostatic charge enables drive)

Question 27

Para crystalline structures

Answer 27

Cell wall type with protein/glycoproteins with hexagonal symmetry Act as sieve = only allow molecules at certain Mr through (excludes large e.g. viruses)

Question 28

Capsules and slime layers

Answer 28

Made either polysaccharides or proteins and constantly replenished Used for: Movement and attachment Bio films Prevents drying out and desiccation (virus attack) Marks it hard for phagocytic cells to recognise = immunity

Question 29

Magnetotaxis

Answer 29

Orientating along earths magnetic field lines | Some cells contain magnetosomes (little piece of metal) that make this happen

Question 30

Gas vesicles

Answer 30

Buoyancy aids = decrease density Aquatic plants = float and photosynthesise Spindle shapes and hollow, made of protein