Biotechnology Flashcards
What are the advantages of using enzymes in biotechnology?
Specificity. Regiospecificity. Stereospecificity.
What is Specificity?
Allows enzymes to carry out a particular operation
What is Regiospecificity?
Enzymes bind to substrates so they can selectively transform a complex substrate at one particular site. Produces highly pure products
What is Stereospecificity?
Biomolecules exist as one of two possible chiral molecules. Important to make sure a pure steroisomer is made
What does specificity allow enzymes to do?
Carry out a particular operation which may be hard to reproduce abiotically eg coupling yeast an mammalian biosynthetic pathways
Describe yeast and mammalian biosynthetic pathways?
- Yeasts engineered to express mammalian enzymes to make hhydrocortisone a metaboilic side product
- Hard to make due to regio and stereospecificity
- Grow yeast in large fermenters then purify
What are the advantages of using enzymes in biotechnology?
- Easy to manipulate/engineer biological systems to alter their properties → express genes of interest in microorganisms, mutagenesis DNA to change coding sequence to alter properties of enzyme
- Natural biodiversity → versatile, wide variety of enzymes → properties from naturally occurring organisms
- Reproducibility/cost → bioprocess can be very effective due to high catalytic activity → specificity → produce a lot of substrate → cost effective → do at lower temperatures
What are the disadvantages of using enzymes in biotechnology?
- Limited temperature range → small windows that the enzymes are active
- Limited pH range → generally near neutral
- Sensitive to organic solvents typically used in chemistry applications
How can we solve the problems of using enzymes?
Use extremophiles and isolate the enzymes
What enzymes are used in washing powder?
Lipase. Protease. SDS.
Why are lipases, protease and SDS good in washing powder?
Work at low temperatures. Resistance to oxidants like hydrogen peroxide.
What enzymes are used in food and drink?
Amylases. Rennet. Invertase.
What does amylase do?
Break down starch to clarify alocholic drinks and fruit juice
What does rennet do?
Protease. Coagulation of milk into cheese. Cost effective.
What does invertase do?
Soft centre in chocolates. Converts sucrose to fructose - sweeter than sugar.
What enzymes are used in medicine?
Blood clotting factors (prevent deep vein thrombosis). Glucose oxidase (diagnostic test strips for blood glucose). Drug biosynthesis eg steroids
Why are enzymes useful in antibiotics?
- Modified penicillin
- Important for development of new antibiotics against resistant strains
- Enzyme processes require less energy and chemical solvents than traditional chemical route → more effective
What are the advantages of in vitro?
- Optimise/control reaction conditions
- Simple product purification
- No biological contamination problems
What are the disadvantages of in vitro?
- Pure proteins not stable indefinitely
- Some reaction require specific inputs
- Can only use one enzyme at a time
What are the advantages of in vivo?
- Cheap/easy to grow many microorganisms
- Link multiple reactions
- Controlled intracellular environment ideal for enzyme function
What are the disadvantages of in vivo?
- Biological contamination
- Potential problems for transporting enzyme substrates to cells
- Unwanted downstream processing of product by organism
How can protein sequences be manipulated for better performance?
- Use site-directed mutagenesis to alter sequence of gene encoding an enzyme
- By introducing mutations into the sequence we can manipulate the DNA sequence of a gene in a directed way
- Impact of site-directed mutagenesis on DNA sequence and resulting protein sequence
- Engineer a protein in washing powder so it can survive harsher conditions eg a protease
