Chapter 9 And 10 Enzymes and energy carriers Flashcards
What biomolecule are enzymes?
Protein
Enzymes are affected by…
Temperature and ph
Enzyme shape
3D
Specific
Definition of an enzyme
It is a biological catalyst made up of proteins which alters the rate of a cellular reaction without being used up in the reaction
2 types of catalysts.
Description and example
Anabolic: enzymes that build up smaller molecules to form larger molecules.
Eg. photosynthesis
Catabolic: enzymes that break down large molecules into smaller molecules.
Eg. Digestive enzymes (starch—amylase—> maltose)
What is the substance that the enzyme acts on called?
What is the substance that the enzyme produces called?
Substrate
Products
Explain the active site
The active site is the part of the enzyme that combines with the substrate
The shape is specific.
Explain induced fit theory
Each substrate will only ‘fit’ the substrate it is designed to work on.
When the substrate enters the active site it causes the active site to change shape slightly.
The enzyme then fits more precisely around the substrate.
Name 3 forms of physical method immobilisation and explain
Enclosed by a membrane: where enzymes are kept within a membrane. Allows substrate in and product out. Enzyme kept in.
Absorption: where enzymes are physically attached to an inert support such as glass beads or ceramic.
Trapped in a gel: sodium alginate used.
Chemical methods of immobilisation
Bonded to a support: chemically bonded to an inert support
Bonded to eachother: chemically bonded to eachother.
Uses of immobilised enzymes (2)
- Enzyme: immobilised glucose isomerase
Substrate: glucose
Product: fructose
Use: makes drinks sweeter - Enzyme: immobilised lactase
Substrate: Lactose
Product: Glucose
Use: Lactose free milk/ condensed milk
Energy Carriers function
Play a vital role in trapping and transferring energy in cellular activities.
What does ADP stand for?
Adenosine Di-Phosphate
What does ATP stand for?
Adenosine Tri Phosphate
What is ADP made up of?
How much energy does it store?
Adenine
Ribose
Two Phosphates
Low energy molecule as there is only one unstable bond.
How is ATP formed?
Amount of energy stored?
A phosphate is added to ADP.
High energy as there are 2 unstable bonds.
The extra unstable bond stores the energy and carries it around the cell.
What the process of ADP+P=ATP called?
Phosphorylation
How does an ATP release its energy?
Loses phosphate.
Bond lost so releases energy.
This energy is used for cellular reactions.
Source of energy (2)
Sun- Light energy
Cellular- Energy released by reactions in a cell.
Where are NADP+ and NADPH used?
Photosynthesis
What does NADP(H) stand for?
Nicotinamide adenine dinucleotide phosphate (hydrogen)
How does NADP+ become NADPH?
2 electrons (e-) and a hydrogen ion (H+) are added.
What is the addition of electrons called?
Reduction
NADP(H) high/low energy?
NADP+ Low energy
NADPH High energy
What are NAD+ and NADH?
They are the same as NADP(H) except they have no phosphate.
Used in Respiration
Describe effect of temperature on enzymes
Low temp = low activity
High temp= high activity
above optimum temp = loses shape and becomes denatured
Describe effect of pH on enzymes
Optimum normally around 7
pepsin= 2
Can become denatured if not optimum
Denaturation
When heated above 40oC (or treated with certain chemicals or radiation) most enzymes lose their 3D shape and thus lose their ability to react with a substrate.
Bioprocessing
Bioprocessing is the use of enzymes-controlled reactions to produce a product.
Advantages of enzyme immobilization
Immobilised enzymes are more stable
Efficiency of the enzyme is unaffected
Easy recovery of product and enzyme at end of reaction
Immobilised enzymes can be reused many times reducing costs to manufacturers
Bioreactor
A stainless steel vessel in which living organisms(bacteria)/enzymes/cells make products
Describe batch culture
Batch Culture
A fixed amount of substrate is placed in bioreactor
Reaction is allowed to proceed
Product is collected at end of reaction
Bioreactor is then cleaned out for the next batch
Describe Continuous flow Culture
Continuous-flow Culture
Substrate is continually infused into the bioreactor
Reaction proceeds and conditions within are strictly controlled using sensors
Product is continually collected
