What affects enzyme activity?

So interesting story, just was about to write my blog and a minor earthquake just happened. Anyway the biochemistry must be go on!

So today we will be doing denaturation. This is going to be very short because the explanations are very simple and I am sure you going to catch on very quickly. The factors which affect the rate at which an enzymes catalyze reactions are substrate concentration, enzyme concentration, temperature and pH.

As substrate concentration increases the initial rate of the reaction increase. This is accounted for by the more substrate which are present the more collision will occur between the substrate and enzyme molecules. This substrate concentration increases until there is a maximum saturation point. Where all the enzyme which are present are occupied by the enzyme. This is called the maximum velocity. The enzyme concentration, temperature and pH are kept constant.

As enzyme concentration increases the rate of reaction also increases. In this case the substance concentration, temperature and pH is kept constant. As the enzyme concentration increases the amount of active sites available for the reaction also increases.However this happens to a maximum point. In this case as the concentration of the enzyme increase however the substance concentration remains the same, so not all the active sites are used up. The rate will remain constant at this point.

As temperature increases the energy of the system also increases. This leads to an increase in the energy of the molecules which cause more collision between the enzyme molecules and the substrate molecules. This also gives the substrate more energy to overcome the activation energy. However as temperature increases over the optimum temperature, the rate reaction decreases significantly. This is as the enzymes are denatured. High temperatures break the hydrogen bonds in the enzyme structure.

The effect of pH on the enzyme is targeted to the ionization if the active site. In acidic conditions the COO- group can be protonated and in a basic solution the NH4+ can be deprotonated. This will interrupt the ionic interactions between the side chains which increases folding.

c8.5x23.denaturation

So that’s it folks. Have a good day!

Reference:

PatriotAPBio2010 – Unit01-Biochemistry

Patriotapbio2010.wikispaces.com. “PatriotAPBio2010 – Unit01-Biochemistry.” 2013. http://patriotapbio2010.wikispaces.com/Unit01-Biochemistry (accessed 9 Mar 2013).

Enzyme Specificity

Hey there! So I have been talking so much about enzymes; their high catalytic powers and their different features. Today I want to spend some time chatting about the specificity of enzymes

What does this really mean? Some enzymes only catalyze one reaction. The enzymes contain an active site which allows the substance to bind to the active by weak interactions. The enzyme then releases the substance when the product has formed.

So there are two theories to explain enzyme specificity: Fisher Lock and Key Hypothesis and Koshland’s induced fit hypothesis.

Let me try and give you a little anology. So you jump out of you red BMW and run to your front door ( yes the high life:) And you pull out your key and push it into your front door lock. The front door lock is the complements the key in your hand. So you push the key into the lock and boom you open your door.

Next scenario, so you jump out of this red BMW again and run to the front door. You have a bag of grocery in one hand and in the next your lap top bag. So you searching in your pocket for your key and finally get it. You try to stick it into the door but it doesn’t fit. So instead of looking down at the key you keep trying to push it into the lock. Finally you put down the bags and look at the key and realize its your car key.

I went through this long story to illustrate to you how the lock and key system operates. The enzyme can be compared to the lock and the key is the substrate. As with the lock and key in the first scenario the enzymes shape is specific to the active site. This allows enzyme to be specific! Only the substrate with the complementary shape to the enzyme active site will be catalyzed. In the second scenario compare the car key to a different substance coming along and trying to fit into the enzyme’s active site. THIS WILL NOT HAPPEN, AS THE ENZYME IS NOT THE COMPLEMENTARY SHAPE TO THE ACTIVE SITE! Please remember that for this hypothesis, the enzyme shape is complementary to that of the active site of the enzymes, NOT the same shape!

lock-and-key-hypothesis

The induced fit hypothesis on the other hand states that the enzymes active site is highly flexible. It is only when the substrate combines to the enzyme’s active site, it induces a change in the enzyme conformation. In the induced fit hypothesis the enzyme changes shape on the substrate bonding. The active site form a shape complementary to the substance only after the enzymes binds to the active site.

induced fit

I hope I made it easy for you to understand. Enjoy people!

references:

Enzymes: Biochemistry: UMDNJ

Njms2.umdnj.edu. “Enzymes: Biochemistry: UMDNJ.” n.d.. http://njms2.umdnj.edu/biochweb/education/bioweb/PreK2010/EnzymeProperties.html (accessed 9 Mar 2013).

For Your Information – The Scientific Blog: THE LOCK AND KEY HYPOTHESIS DISCUSSION

Ourlifesciences.blogspot.com. “For Your Information – The Scientific Blog: THE LOCK AND KEY HYPOTHESIS DISCUSSION.” n.d.. http://ourlifesciences.blogspot.com/p/lock-and-key-hypothesis-discussion.html (accessed 9 Mar 2013).

Turnover number

Hey guys, whats up? Hope you learning some pretty interesting stuff. So one of the things that i mentioned in the last post were that enzymes have this incredible catalytic power. What I mean by that is these enzymes are able to catalyze reactions very efficently and allow the reactions to occur over 1000 times faster than it would without the enzymes

Biochemist have a special name for measuring the amount of time take for products to be formed from substrates. The turnover number is described as the number of molecules of substrates converted to product per enzyme molecule per second.

One of the fastes enzyme out there is acetylcholinesterase. Acetylcholinesterase is a serine protease that hydrolyzes the neurotransmitter acetylcholine. Below is the chemical steps of this process:

acetylcholine_hydrolysis2

One of the earliest turn over number given to this enzyme was  3 x 107  per minute.

This means that every minute 30000000 substrates are converted to products. This means that every second 1800000000 reactants are converted to products.

That is an amazing figure. That is not like 100 or even 1000! This figure is expressed in millions. This shows how much catalytic power an enzyme has and how incredible  fast it can work.

Just thought I would share that with you.

love peace chicken grease

 

References:

Enzymes: Biochemistry: UMDNJ

Njms2.umdnj.edu. “Enzymes: Biochemistry: UMDNJ.” n.d.. http://njms2.umdnj.edu/biochweb/education/bioweb/PreK2010/EnzymeProperties.html (accessed 9 Mar 2013).

 

 

Enzymes are here

Good night or should I say good morning? I have not been here for a while due to circumstances beyond my control, but we need to get back up to speed, so lets get to it!

So now we are doing enzymes in class. Enzymes are simply biochemical molecules which catalyzes a reaction without being altered itself. I know that we all have heard about enzyme some where in our career, so this introduction should not be too hard. First let me link you with my biochem teacher video. I would then pull out the main points for you.

https://www.youtube.com/watch?v=qcA57r2gBL8

So let me summarize this video for you with some quick main points:

There are many different types of enzymes such as ribozymes (this is an RNA molecule which catalyzes specific chemical reactions) and abzymes ( These are antibodies which express great catalytic activity).

Enzymes are present for life on this earth. Without enzymes reactions would occur too slowly in organism, which could possibly lead to death.

Transition state is the intermediate between the structure of the reactants and the structure of the products which has the highest energy. A lot of persons mix up transition state, so I will try and source a video that explains it a little better.

Activation energy the minimum amount of energy needed for the reaction to occur.

EA

Enzymes have very high catalytic power. They can transform over 1000 reactants to products in seconds.

There are five classes of enzymes: oxidoreductases, transferases,hydroloses,lyases,isomerases and ligases.

A co-enzyme is any protein substituent which assist in the functioning of the enzyme.

So these are just some main points to help you follow.

In my opinion the video was very well put together. It highlighted the points which were needed to be known and also was very interactive. It makes the information very easy to learn and I look forward to other videos.

Peace, love and chicken grease.

References:

Njms2.umdnj.edu. “Enzymes: Biochemistry: UMDNJ.” n.d.. http://njms2.umdnj.edu/biochweb/education/bioweb/PreK2010/EnzymeProperties.html (accessed 9 Mar 2013).