In this IBDP Biology post, we will look at:
- How metabolic pathways are controlled
- Rates of reaction calculations
- Causes and formation of Malaria
METABOLIC PATHWAYS CONTROLLED
End-product in metabollic pathway binds to an enzyme at the start of the pathway - this stops the metabollic pathway until the end-product concentration decreases
The higher the concentration of end-product the quicker the metaollic pathway stops
Isolucine inhibits threonine dehyrdase
- Bacteria synthesize isoleucine from threoine in a series of five enzyme catalysed steps
- As the concentration of isoleucine increases so of it binds to the allosteric site of threonine deaminase
- Isoleucine acts as a non-competitive inhibitor to thereonine deaminase
- The pathway is then turned off regulating isoleucine production
- If the concentration of isoleucine later falls then the allosteric sites of thereonine deaminase are empied and the enzymes recomences the conversion of thereonine to isoleucine
CALCULATING RATES OF REACTION
Measure:
- Quantity of substrate used per unit time
- Quantity of product formed per unit time
These quantities can be measured in mass or volume
SI unit of time for rate per second is (s−1)
BIOINFORMATICS
Bioinformatics: An approach whereby multiple research groups can add information to a database enabling other groups to query the database
Chemogenomics: Bioinformatics has facilitated research into metabollic pathways
- Sometimes when a chemical
binds to a target site it can significantly alter the metabollic activity
- Many chemicals are
tested individually on a range of related organisms
- For each organism target sites are identified
- Range of chemicals which are known to work on those sites are tested
MALARIA
- Malaria is caused by a
pathogen called Plasmoidum falciparum
- This protozoan uses mosquitoes and humans as
hosts so can be passed on by mosquitoes
- Increasing resistance to anti-malarial drugs has lead to use of Bioinformatics and Chemogenomics to try and identify new drugs
In one study approx 3 000 chemical were screened against a chloroquine-sensitive 3D7 strain and the chloroquine-resistant K1 strain of P. falciparum
- Other related and non-related organisms including human cell lines were also screened
- 19 new chemicals that inhibit the enzymes normally targeted by anti-marial drugs were identified
- Additional 15 chemicals that bind to malarial proteins were identified - helps to locate Plasmodium faliciparum
- These findings indicate new directions for drug research
That's all!
References:
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fsecondaryscience4all.wordpress.com%2Fgcse-chemistry-aqa%2Fgcse-chemistry-c2%2Fc2-4-rates-of-reaction%2F&psig=AOvVaw3c1_s8CAd4Dautcqi4SkZH&ust=1625847160239000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCODf8Ofu0_ECFQAAAAAdAAAAABAD
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fopenoregon.pressbooks.pub%2Fmhccmajorsbio%2Fchapter%2F6-7-feedback-inhibition-in-metabolic-pathways%2F&psig=AOvVaw12yYhQfIVPx5U-o3h1z21d&ust=1625847272278000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCJij6pzv0_ECFQAAAAAdAAAAABAD
- https://www.google.com/url?sa=i&url=https%3A%2F%2Ftenor.com%2Fsearch%2Fbright-sun-gifs&psig=AOvVaw0FtSzKiTwOceZLOzJi7Uni&ust=1625736681287000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCOjlrJ3T0PECFQAAAAAdAAAAABAx
Drafted by Venetia (Biology)