Lecture 5 Flashcards
What is HFCS?
High Fructose Corn Syrups - most commonly used in soft drinks and primary ingredient in most pancake syrups
How is High Fructose syrup produced?
Liquefaction (corn starch) + saccharification (amylases) = glucose - isomerase - fructose
What are amylases?
Enzymes that hydrolyse starch
Process of starch sarrcharification?
Starch - short-chain polymers (dextrins) - maltose (disaccharides) - glucose
What are the most important enzymes in the starch saccharification process?
Alpha-amylases, glucose isomerases and glucoamylases
How is starch converted to glucose?
By enzyme hydrolysis
What is the adv of starch hydrolysis over direct sugar production?
The starting materials - wheat, corn, cassava - non perishable whereas sugar beet is only available about 100 days a year
For commercial applications alpha-amylase is derived from?
Bacillus strains
Bacillus licheniformis, Bacillus stearothermophilus, Bacillus amyloliquefaciens are the ones important in HFCS production
What produces glucose isomerase?
Streptomyces strains
Streptomyces murinus strain NZYM-GA produced by the enzyme company Novozymes A/S
Where do glucoamylases occur and what are commercial glucoamylases produced by?
Most glucoamylases occur in fungi
Commericial glucoamylases are typically produced by Aspergillus niger
What catalyses the initial hydrolysis of starch and how?
alpha-amylases catalyse the initial hydrolysis of starch into shorter oligosaccharides through the cleavage of alpha-D-(1-4) glycosidic bonds
What do glucoamylases do?
Glucoamylase hydrolyzes polysaccharides from the nonreducing chain ends by cleaving alpha-1,4 and alpha-1,6 glycosidic bonds consecutively
Enzymatic liquidification conditions?
Enzymatic liquidification is carried out at 110 degrees C with amylases from Bacillus, which are added to the solution before conversion to paste
Starch solutions liquified w alpha amylases can be saccharified with glucosamylase at pH4-5 and at 55-60 degrees C
What does glucose isomerase do?
Converts Glucose to fructose by isomerisation
LOOK AT HOW FRUCTOSE SYRUP IS OBTAINED DIAGRAM
What is a GMO and what is its purpos?
Genetically modified organism - an organism whose genome has been altered
-Genetic engineering allows expression of euk genes in pro (e.g insulin)
-This is achieved by cloning the gene via mRNA
What does the process of expressing a recombinant mammalian protein in an expression system require?
1) Identification of the gene that encodes the protein of interest
2) Generation of cDNA from the respective mRNA selection of suitable expression vector to insert the gene sequence
3) Selection of suitable system that can express the vector
4) Appropriate screening and scaling up methods
What are spliced out of the sequence before translated into mRNA?
Introns
Look at cDNA from mRNA - Reverse transcription
What are problems associated with protein synthesis in a foreign host?
-Degradation by intracellular proteases
-Toxicity to prokaryotic host
-Formation of inclusion bodies
Where does RNA polymerase bind on the plasmid?
Binds at the promoter and synthesises the gene
What does the origin of replication on the plasmid allow?
Allows the plasmid to replicate
What was the first human protein made commercially by genetic engineeri ng?
Insulin
what is Somatotropin and what is it used in?
A growth hormone that is widely produced by being genetically engineered - cloned as cDNA from the mRNA
-Recombinant bovine somatotropin (rBST) is commonly used in dairy industry - stimulates milk production in cows
Process of cloning and expression of bovine somatotropin?
-Convert Bovine Somatotropin (BST) mRNA from cow to cDNA using reverse transcriptase
-Transform the Bovine somatotropin cDNA and the expression vector that contains the bacterial promoter and Ribosomal binding site (RBS) into the cells of Escherichia coli
-Commercial production of recombinant bovine somatotropin (rBST)
-Inject rBST into cow to increase milk yield
Look at table 15.6 that shows therapeutic products made by genetic engineering
Examples of medicinal applications of human recombinants that have replaced animal or harvested from human types?
Human growth hormone
Human insulin
Follicle stimulating hormone
Factor VIII
New recombinant human growth hormone?
(rHGH) : Humatrope from Lilly replacing cadaver (pituitary glands) harvested from human growth hormone
New recombinant Human Insulin?
(BHI): Humulin from Lilly and Novolin from Novo Nordisk among others largely replaced bovine and porcine insulin for human therapy
New recombinant Follicle-Stimulating Hormone?
(FSH): as a recombinant gonadotropin preparation replacing Serono’s Peragol which was previously isolated from post-menopausal female urine
New recombinant Factor VIII?
From Kovaltry from Bayer, replacing blood harvested factor VIII
(Blood clotting protein for people who suffer from Hemophilia A)
