Secondary metabolites 1

Question 1

when are secondary metabolites produced

Answer 1

stationary phase of growth after main growth phase has ended

Question 2

what is different about secondary metabolites and primary metabolites

Answer 2

primary metabolites have common shared paths across organisms, whereas secondary metabolites produced by an organism are specific biochemical pathways specialised to that organism

Question 3

at what growth stage are secondary/ primary produced in

Answer 3

primary - tropophase

secondary - idiophase

Question 4

3 functions of secondary metabolites

Answer 4

• reducing competition - limiting others around
• storage compounds - later can be broken down
• maintains metabolism so that the organism could start growing again if it wanted to

Question 5

what are polyketides

Answer 5

structurally diverse group of organic acids, all with the same backbone

Question 6

name 3 important/common polyketides

Answer 6

doxycycline, erythromycin - antibiotics

Aflatoxin B1

Question 7

basic structure of polyketides

Answer 7

either a 2 carbon/ 3 carbon starting point, sugar side chains can be added - glycosylated

Question 8

What are polyketides primarily formed by

Answer 8

fungi, and actinomycete bacteria - filamentous - look like fungi

Question 9

what are some other examples of benefits of polyketides

Answer 9

cholersterol-lowering, immunosuppressants, anti-cancer/parasitic/fungal

Question 10

where are aflatoxins found

Answer 10

produced from microorganisms found on corn

Question 11

what is a protein domain

Answer 11

specialised enzymatic production, new proteins evolve by bringing together new domains, they fold independently of the protein

Question 12

what is a protein module

Answer 12

1-6 domains coming together to carry out a function

Question 13

what are PKS

Answer 13

polyketide synthase enzymes - the 2c starting unit loads onto the enzyme and moves through it adding on 2 carbons, one being lost as CO2 - gradually gets bigger and bigger polyketide

Question 14

what are the two types of PKS enzymes

Answer 14

type 1 - form more complex PKs, they are a very large single protein with multiple domains
type 2 - form simple PKs, they are several different polypeptides each with a specific domain coming together as one - bound together to form a quaternary protein

Question 15

what antibiotoc is used for acne

Answer 15

arythromycin

Question 16

what are statins and how do they work

Answer 16

a drug that blocks the enzyme HMG - CoA in the liver that produces cholesterol - acts as a competitive inhibitor blocking production

Question 17

what is gene localisation

Answer 17

genes involved with other processing are often clustered within the same enzyme in the same location of the genome

Question 18

what is amphoteraicin

Answer 18

an anti-fungal drug used to treat thrush

Question 19

how does amopheteraicin work

Answer 19

humans have cholesterol to strengthen the membrane, whereas fungus have ergosterol - the drugs target the ergosterol - cell leakage - then death

Question 20

why are fungal infections so hard to treat

Answer 20

because human cells and fungal cells are very similar - both eukaryotes - drugs can easily harm humans as well as the fungal cells

Question 21

what is griseofulvin

Answer 21

anti-fungal drug used to treat ringworm and nail infections

Question 22

how does griseofulvin work

Answer 22

prevents the assembly of fungus microtubules and mitosis

Question 23

what is doxorubicin

Answer 23

anti-tumour drug - used in cancer chemotherapy - fermentation of GM engineered strain of Streptomyces

Question 24

how does doxorubicin work, and what are the problems

Answer 24

stops DNA replication, could interfere with normal cell growth

Question 25

what do avermectins treat

Answer 25

blocks nerve transmission in nematode/arthropod/ parasitic infections