primary metabolites

Question 1

what is the molecular structure of fatty acids

Answer 1

hydrocarbons with carboxyl COOH with variable amounts of double bonds

Question 2

what is FAS

Answer 2

fatty acid synthase- an enzyme which makes saturated fatty acids up to 16 carbons in length

Question 3

what is EL

Answer 3

elongase- adds 2 carbons to existent fatty acid chains

Question 4

what enzyme has the symbol of a triangle, or delta

Answer 4

desaturases- adds double bonds at specific points in the hydrocarbon chain

Question 5

what is cis

Answer 5

hydrocarbons with naturally existing double bonds. they have a kink in their structure which creates space in membranes and promotes fluidity

Question 6

what is trans

Answer 6

hydrocarbons where double bonds are added through hydrogenation. there are no kinks and properties are more similar to saturated hydrocarbons

Question 7

what are three functions of fatty acids

Answer 7

cell membranes, storage of carbon (as they don’t store water so they take up less space) and production of eicosanoids (short chain hormones)

Question 8

what fatty acids can humans make naturally

Answer 8

palmitic (16:0), stearic (18:0 EL) and oleic (18:1 delta9), none of which can make eicosanoids

Question 9

what fatty acids are essential in diet to make eicosanoids

Answer 9

linoleic (n-6) and linolenic (n-3) 18 chain, from which all eicosanoids can be made using EL, delta 5 and delta 6

Question 10

what foods are fatty acids found in

Answer 10

nuts and seeds provide 18 chain n-6 and n-6, oily fish provide 20 chain fatty acids and can help prevent heart disease

Question 11

what is the main source of 20:4,n-6

Answer 11

Mortierella alpina- sequencing found the presence of delta 5,6,9 and 12

Question 12

what is the safest vector for producing fatty acids

Answer 12

Saccharomyces cerevisiae, as is known by its common use in beer. however, it does not have any delta 6 or 12

Question 13

how do M. alpina and S. cerevisiae work together

Answer 13

delta 6 and 12 from M. alpina are introduced to S. cerevisiae on one plasmid, and they now produce both linoleic and linolenic acids

Question 14

what are the requirements for vectors producing fatty acids

Answer 14

must be cheap, safe and have a high yield but not be readily available elsewhere as this would make the marked more competitivity

Question 15

what do Martek Biosciences do

Answer 15

they produce M. alpina on mass, one commercial use of which being formula milk

Question 16

what produces citric acid

Answer 16

Aspergillus niger which operates at a low risk

Question 17

where is citric acid produced

Answer 17

in the krebs cycle- it is often fuelled by cheaper sucrose which is converted to glucose. attempts to accumulate the acid can actually slow glycolysis or affect the energy supply of the host

Question 18

where is glutamic acid produced

Answer 18

downstream of citric acid krebs- it had not been improved since the original strain

Question 19

what is lycine

Answer 19

an essential fatty acid- it has been modified to produce a much higher yield by incorporating 12 genomic traits which remove limiting factors/ bottlenecks

Question 20

what types of enzyme do microorganisms produce

Answer 20

endoenzymes and exoenzymes

Question 21

what are the main application of microorganism- made enzymes

Answer 21

agriculture, environment and industry

Question 22

how are microorganisms produced

Answer 22

continuously, by batch or by fed batch

Question 23

how does fungi grow best

Answer 23

solid state fermentation eg rice or wheat

Question 24

what enzymes are used in detergent

Answer 24

proteases, amylases, lipases and cellulases

Question 25

what enzymes are used in baking

Answer 25

amylases, xylanases and glucose oxidases

Question 26

what enzymes are used in fruit juice

Answer 26

pectinases increase juice yield by hydrolysing the fruit cell walls

Question 27

what enzymes are used in brewing

Answer 27

amylases reduce the viscosity and increase fermentable sugars- useful in low calorie beer

Question 28

what enzymes are used in confectionary

Answer 28

invertases and amylases are used in confectionary

Question 29

what is second generation biofuel

Answer 29

it uses biological waste instead of crop. cellulases, amylases and ligninases release sugars which are fermented to produce ethanol

Question 30

what is a hetrolygous protein

Answer 30

a protein produced in a different host than where the encoding genes originally came from

Question 31

what are the adaptations for use of hetrolygous proteins from eukaryotes

Answer 31

cDNA can be used instead of mRNA as it doesn’t have any introns

Question 32

what are pre/pro sequences

Answer 32

sequences added to hetrolygous genes as signal sequences for expotation of the product. they can be linked to the protein or to a carrier protein- either way a KR sequence is used

Question 33

how is insulin produced

Answer 33

hetrolygously by S. cerevisiae- more efficient than E. coli

Question 34

how in chymosin produced

Answer 34

hetrolygously by A. niger with a transport protein. it is unusual as it is self- cleaving from pre/pro so doesn’t need an external peptidase