IB Biology‎ > ‎Chemistry of Life‎ > ‎

Enzymes (2.5/8.1)



Enzyme Simulation Website

http://www.kscience.co.uk/animations/enzyme_model.htm

*Hit "Set Up" and manipulate the environment.


YouTube Video


YouTube Video


 

Great Enzyme Animation

Protein Denaturation


2.5 Enzymes

Nature of science:

Experimental design—accurate, quantitative measurements in enzyme experiments require replicates to ensure reliability. (3.2)

Understandings:

Enzymes have an active site to which specific substrates bind.

Enzyme catalysis involves molecular motion and the collision of substrates with the active site.

Temperature, pH and substrate concentration affect the rate of activity of enzymes.

Enzymes can be denatured.

Immobilized enzymes are widely used in industry.

Applications and skills:

Application: Methods of production of lactose-free milk and its advantages.

Skill: Design of experiments to test the effect of temperature, pH and substrate concentration on the activity of enzymes.

Skill: Experimental investigation of a factor affecting enzyme activity. (Practical 3)

Guidance:

Lactase can be immobilized in alginate beads and experiments can then be carried out in which the lactose in milk is hydrolysed.

Students should be able to sketch graphs to show the expected effects of temperature, pH and substrate concentration on the activity of enzymes. They should be able to explain the patterns or trends apparent in these graphs.

Theory of knowledge:

Development of some techniques benefits particular human populations more than others. For example, the development of lactose-free milk available in Europe and North America would have greater benefit in Africa/Asia where lactose intolerance is more prevalent. The development of techniques requires financial investment. Should knowledge be shared when techniques developed in one part of the world are more applicable in another?

Utilization:

Enzymes are extensively used in industry for the production of items from fruit juice to washing powder.

Essential idea: The structure of DNA allows efficient storage of genetic information.

8.1 Metabolism

Nature of science:

Developments in scientific research follow improvements in computing—developments in bioinformatics, such as the interrogation of databases, have facilitated research into metabolic pathways. (3.8)

Understandings:

Metabolic pathways consist of chains and cycles of enzyme-catalysed reactions.

Enzymes lower the activation energy of the chemical reactions that they catalyse.

Enzyme inhibitors can be competitive or non-competitive.

Metabolic pathways can be controlled by end-product inhibition.

Applications and skills:

Application: End-product inhibition of the pathway that converts threonine to isoleucine.

Application: Use of databases to identify potential new anti-malarial drugs.

Skill: Calculating and plotting rates of reaction from raw experimental results.

Skill: Distinguishing different types of inhibition from graphs at specified substrate concentration.

Guidance:

Enzyme inhibition should be studied using one specific example for competitive and non-competitive inhibition.

Theory of knowledge:

Many metabolic pathways have been described following a series of carefully controlled and repeated experiments. To what degree can looking at component parts give us knowledge of the whole?

Utilization:

Many enzyme inhibitors have been used in medicine. For example ethanol has been used to act as a competitive inhibitor for antifreeze poisoning.

Fomepizole, which is an inhibitor of alcohol dehydrogenase, has also been used for antifreeze poisoning.

Aims:

Aim 6: Experiments on enzyme inhibition can be performed.

Aim 7: Computer simulations on enzyme action including metabolic inhibition are available.

Essential idea: Energy is converted to a usable form in cell respiration.

ĉ
Jessica Clark,
Nov 13, 2013, 1:19 PM
ĉ
Jessica Clark,
Nov 13, 2013, 1:19 PM
Ċ
Jessica Clark,
Oct 18, 2013, 10:46 AM
Ċ
Jessica Clark,
Oct 22, 2013, 8:10 AM
ĉ
Jessica Clark,
Nov 13, 2013, 1:19 PM
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