ODWS icon

The Open Door Web Site
HOMEPAGE BIOLOGY HOMEPAGE CHEMISTRY PHYSICS ELECTRONICS HISTORY HISTORY OF SCI & TECH MATH STUDIES LEARNING FRENCH STUDY GUIDE  PHOTO GALLERY
IB BIOLOGY HOMEPAGE SCIENTIFIC INVESTIGATIONS DRAWING IN BIOLOGY DRAWING TABLES ERROR ANALYSIS IN BIOLOGY ALL ABOUT GRAPHS ICT IN BIOLOGY STATISTICS SCIENTIFIC POSTERS MOLECULAR IMAGES
WS

 

Powerpoint Presentation: Enzymes

Biochemistry: Enzyme Index

Enzymes
Enzyme Mechanisms
Inhibitors
Enzymes and Homeostasis
Enzymes and Biotechnology
Catalase

Topic Chapters Index

 

The effect of temperature

Q10 (the temperature coefficient) = the increase in reaction rate with a 10°C rise in temperature.

For chemical reactions the Q10 = 2 to 3
(that is the rate of the reaction doubles or triples with every 10°C rise in temperature)

Enzyme-controlled reactions follow this rule as they are chemical reactions.

BUT at high temperatures proteins denature

The optimum temperature for an enzyme controlled reaction will be a balance between the Q10 and denaturation.

Effect of temperature

For most enzymes the optimum temperature is about 30°C.
Many are a lot lower, cold water fish will die at 30°C because their enzymes denature.

A few bacteria have enzymes that can withstand very high temperatures up to 100°C.

Most enzymes however are fully denatured at 70°C.

 

BIOCHEMISTRY

Custom Search

Factors that effect Enzyme Activity

Substrate concentration

Graph substrate concentration

Non-enzymic reactions

The increase in velocity is proportional to the substrate concentration

 

 

Enzymic reactions

Are faster but they reach a saturation point when all the enzyme molecules are occupied.

If you alter the concentration of the enzyme then Vmax will change too.

 

The effect of pH

The effect of pH

Extreme pH levels will produce denaturation.
The structure of the enzyme is changed.
The active site is distorted and the substrate molecules will no longer fit in it.

At pH values slightly different from the enzyme’s optimum value, small changes in the charges of the enzyme and its substrate molecules will occur. This change in ionisation will affect the binding of the substrate with the active site.

Note: The pH at which the enzyme molecule’s charges are equal is called its isoelectric point. This corresponds to its optimum pH. On an electrophoresis gel the enzyme would not move as it has no overall charge at this pH.

 

The Open Door Web Site is non-profit making. Your donations help towards the cost of maintaining this free service on-line.

Donate to the Open Door Web Site using PayPal

SITE MAP
WHAT'S NEW?
ABOUT

PRIVACY

COPYRIGHT

SPONSORSHIP

DONATIONS

ADVERTISING

© Paul Billiet 2018
Any questions or problems regarding this site should be addressed to the webmaster

Hosted By
Web Hosting by HostCentric


SiteLock