bio

ok guess what. just finished revising bio. except for enzymes so i guess i'll revise here.

1. Metabolism
Anabolism = building up from small to large substance
Catabolism = breaking down of large to small substance

Exergonic = stored to free energy
Endergonic = Free to stored energy

2. Enzymes
Helps to speed up chemical reactions without being altered in the process.

Factors:
a. Substrate concentration / Enzyme concentration
b. Temperature - optimum because as temperature rises, particles move faster and have more energy so easily to reach transition state and the required activation energy. but enzymes denature permanently if temperature too high
c. pH

Initial rates of reactions: Tangent to x=0

3. INDUSTRIAL USES
a. Why use biological catalysts instead of inorganic catalysts?
- Highly specific, will not create too much waste products
- High turnover rates. Small amount of enzymes still produce large amounts of products
- Work at normal temperature and pH so less energy input required -> cheaper

b. Why use enzymes from microorganisms?
- They live in a variety of habitats so can find those which can withstand extreme physical conditions such as extreme temperatures or pH
- Grown economically in bulk fermenters (cheaper)
- Grows rapidly and high enzyme to mass ratio
- Easily genetically modified
- Growth not limited by climate or season

c. Why cell-free instead of whole-cell preparations
Advantage:
- No unwanted byproducts produced by other enzymes of microorgnisms (not that enzymes are not specific)
- Products do not get built up and used in microorganism. So higher productivity.

Disadvantage:
- Hard to extract enzyme
- Unstable

d. Why use immobilised enzymes?
- So that products can be enzyme free.
- Enzymes are more stable and can last longer
- Enzymes can be reused (cheaper)

e. Industrial Uses
- Biological detergents (with enzymes like proteases, lipases, celluloses... stored in capsules that only release contents when there is water because they cause irritance)
- Medical treatment for thromboses (atherosclerosis -> blood clotting -> use enzymes to dissolve blood clots)
- Analytical uses (e.g. Test for glucose conc. in urine. Glucose oxidase, peroxidase.)
- Fruit juice production (increases productivity by 20%)
- Lactose-free milk (some people cannot produce lactase in their pancreatic juices. so they have to consume lactose free milk so that no bacteria acts on lactose to cause diarrhea. so pass milk through immobilised lactase)
- High sucrose juice?

lol. ok. DONE. wth. so long. and this is just a small part of a big topic.

k bye.

Patrick