Secondary metabolites 1 Flashcards
when are secondary metabolites produced
stationary phase of growth after main growth phase has ended
what is different about secondary metabolites and primary metabolites
primary metabolites have common shared paths across organisms, whereas secondary metabolites produced by an organism are specific biochemical pathways specialised to that organism
at what growth stage are secondary/ primary produced in
primary - tropophase
secondary - idiophase
3 functions of secondary metabolites
- 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
what are polyketides
structurally diverse group of organic acids, all with the same backbone
name 3 important/common polyketides
doxycycline, erythromycin - antibiotics
Aflatoxin B1
basic structure of polyketides
either a 2 carbon/ 3 carbon starting point, sugar side chains can be added - glycosylated
What are polyketides primarily formed by
fungi, and actinomycete bacteria - filamentous - look like fungi
what are some other examples of benefits of polyketides
cholersterol-lowering, immunosuppressants, anti-cancer/parasitic/fungal
where are aflatoxins found
produced from microorganisms found on corn
what is a protein domain
specialised enzymatic production, new proteins evolve by bringing together new domains, they fold independently of the protein
what is a protein module
1-6 domains coming together to carry out a function
what are PKS
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
what are the two types of PKS enzymes
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
what antibiotoc is used for acne
arythromycin
what are statins and how do they work
a drug that blocks the enzyme HMG - CoA in the liver that produces cholesterol - acts as a competitive inhibitor blocking production
what is gene localisation
genes involved with other processing are often clustered within the same enzyme in the same location of the genome
what is amphoteraicin
an anti-fungal drug used to treat thrush
how does amopheteraicin work
humans have cholesterol to strengthen the membrane, whereas fungus have ergosterol - the drugs target the ergosterol - cell leakage - then death
why are fungal infections so hard to treat
because human cells and fungal cells are very similar - both eukaryotes - drugs can easily harm humans as well as the fungal cells
what is griseofulvin
anti-fungal drug used to treat ringworm and nail infections
how does griseofulvin work
prevents the assembly of fungus microtubules and mitosis
what is doxorubicin
anti-tumour drug - used in cancer chemotherapy - fermentation of GM engineered strain of Streptomyces
how does doxorubicin work, and what are the problems
stops DNA replication, could interfere with normal cell growth
what do avermectins treat
blocks nerve transmission in nematode/arthropod/ parasitic infections
