Enzymes are biological catalysts that speed up chemical reactions without being changed in the end. This is achieved by the enzymes providing an alternative pathway with a lower activation energy. Activation energy is the minimum amount of energy needed for a reaction to occur. This can be seen using an energy profile diagram. Most enzymes are protein molecules although some are RNA molecules called ribozymes.
Enzymes are important as they allow metabolic reactions necessary for the sustenance life to occur in seconds. Without them, these reactions would occur to slow for life to be sustained. During these reactions the substrate’s bonds are broken to form the product. The highest energy arrangement of atoms that contains a structure intermediate between that of the reactants and products is referred to as the Transition State. The distinctive features of enzymes include their catalytic power, their regulation and their specificity. The number of molecules of substrate converted to product per enzyme molecule per second is called the turnover number or Kcat.
Enzymes are named based on their substrates, based on the action they perform and some just end in ‘ase’. Enzyme names usually end in ‘ase’, however there are a few exceptions. They are given numbers called enzyme commission numbers (EC), based on their class, subclass and sub-subclass. There are six classes of enzymes, oxidoreductases, transferases, hydrolases, lyases, isomerases and ligases, each with categorizing functions. Enzymes need non-protein components to help them work called cofactors. This can be subdivided into inorganic cofactors and organic cofactors. Organic cofactors can be transiently associated in which case they are Cosubstrates or permanently associated in which case they will be Prosthetic groups.
Apoenzyme- inactive protein part
Cofactor- non-protein part
Haloenzyme- active enzyme
The apoenzyme with the cofactor gives the haloenzyme .
Inorganic catalyst can be compared to enzymes by looking at industrial processes such as the haber and contact process .These inorganic catalysts, unlike enzymes which work at normal body temperature, require very high temperatures and pressures in order to work. Enzymes are more efficient and due to their specificity and like inorganic catalysts, they do not have any side reactions occurring, thereby ensuring 100% product manufacture. Inorganic catalyst cannot be regulated are may be poisonous.
This video was very informative and well put together. I appreciated the use of colour to highlight important point and also as a separator, as a person who gets bored quickly it helps. there was one badly coloured part however, the equation with sucrose, where I found it difficult to follow, and had to really focus to read it. I’m not sure if this was the intention of the individual, but if so, mission accomplished. the beginning of the video was also a bit unclear as I could not clarify the names of the scientist being mentioned and therefore went on a google hunt with the bits of name that I could make out. I would have also preferred if the photo of the scientist was a little bigger, although I am aware that they are not apart of the major topic, but I would have still preferred to see their ingenious faces. Generally I enjoyed the video, despite these one or two issues, it did what it was intended to which makes it very successful in my eyes.