The multipurpose enzyme


Enzymes are quite amazing. An enzyme works by lowering the activation energy of the substrate to allow chemical reactions to occur at a faster rate.  With the absence of enzymes, life will cease to exist as we know it. Vincent Fischetti and colleagues at Rockefeller University in New York isolated the enzyme, called Pal, from a bacteriophage (a type of virus that infects bacteria) that targets S. pneumoniae. The bacterium Streptococcus pneumoniae can cause problems ranging from ear infections to potentially deadly diseases like pneumonia and meningitis and is found in the nose and throat of humans.

The enzyme isolated from the bacteriophage displayed specificity as it only affected the bacterium and did not affect any other bacteria that are found in the nose. Again due to the specificity of the enzyme, the bacterium does not seem to develop any resistance to the enzyme as they do with antibiotic drugs.

Indeed the enzyme is very important. Not only in the requirement to speed up a reaction, but as seen with the bacterium Streptococcus pneumonia, it can also be used medically to protect from potentially dangerous diseases.



My first crossword…..


Here we have some practice on nucleic acid







X-ray crystallography

Ribonucleic acid





Double helix

Phosphodiester bond

Hydrogen bonds



Aromatic stacking


Oxidative metabolism


Confusion: The polysaccharides

13 Polysaccharides

Have you ever taken a good look at the polysaccharides? The soon seem to resemble each other. There are some polysaccharides that are usually confused with each other due to their type of bonging. Before we go into this, we first need to know the definition of the polysaccharide. The polysaccharides are sugar polymers containing more than 20 or so monosaccharide units, and some have hundreds or thousands of units. Some polysaccharides, such as cellulose, are linear chains; others such as glycogen are branched. Both glycogen and cellulose consist of recurring units of D-glucose, but they differ in the type of glycosidic linkage and consequently have strikingly different properties and biological roles (Nelson and Cox 2004, 238).  The polysaccharides will be discussed are glycogen, cellulose and starch. The table below shows the monosaccharide, bonding and a diagram to help differentiate between the polysaccharides.


Polysaccharide Monosaccharide Bonds Diagram
Starch: Amylose α-glucose 1-4  amylose
Starch: Amylopectin α-glucose 1-4 and 1-6  amylopectin
Glycogen α-glucose 1-4 and 1-6 (more 1-6 than amylopectin  glycogen
Cellulose β- glucose 1-4  cellulose



















Nelson, David L., and Cox, Michael M..2004. Lehninger Principles of Biochemistry

The jingle


Have you ever watched television and noticed that the jingle sticks in your head? I’m sure that most of you wished that all of  your school work could be learnt just the same.  The following is a little poem that I hope will aid in memory of the six major classes of enzymes.

There are six major classes of enzymes

You should learn them all in your free time

The classes must be learnt in order

To avoid complications with the EC number

Oxidoreductase is first to be told

Oxidation and reductions is how they roll

Transferase comes in at number two

Group transfer reaction is what they do

Hydrolayses is in the third row

Breaking bonds by hydrolysis is how they go

Ligases is at number four

Similar to number three but water is no more

Isomerase is fifth with no real bother

It simply converts one isomer to another

Ligases at number six finally,

With bond formation by hydrolysis of high energy phosphate like ATP

by biochem1362

Multiple Choice: The TCA/ ETC


Multiple choice – TCA/ ETC

1. Using figure 1 below, which of the labels are incorrect?

mitochondria 2

Figure 1: The mitochondria

2. Where is the cytochrome situated in the mitochondria

A. Inner membrane

B. Matrix

C. Outer membrane

D. Cytoplasm

E. Cytosol

3. How many cytochromes are present

A. 2

B. 5

C. 8

D. 4

E. 2

Fill in the blanks for questions 4 to 6

4. __________________ are of high energy transfer potential

A. Protons
B. Electrons
C. Neutrons
D. Complexes
E. ATP synthase

5. Cytochromes ____, ____ and ____ are involved in the pumping of protons

A.1,3 and 4
B. 1,8 and 5
C. 4,2and 1
D. 1,2 and 3
E. 1,5 and 6

6. The inner membrane is _________________ to H+ ions



C. Impermeable

D. Electrophilic

E. Hydrophilic

7. The electrochemical gradient is set up due to

A.Pumping of protons from the matrix to the inner membrane space

B. Diffusion of electrons from the matrix to the inner membrane space

C. Osmosis of protons from the matrix to the inner membrane space

D.Pumping of electrons from the inner membrane space to the matrix

E. Diffusion of protons from the inner membrane space to the matrix

8. What does oligomycin do?

A.Binds to cytochrome 1

B. Pumped from the outer membrane to the inner membrane

C. Inhibits cytochrome 2

D.Create the electromotive force

E. Binds and inhibits ATP synthase

9. Which enzyme is not found in the matrix of the mitochondria?


B. Enolase

C. Phosphoglycerate kinase

D.Succinate dehydrogenase

E. Lactate dehydrogenase

10. What is the role of oxygen in the ETC?

A.To be pumped from the outer membrane to the inner membrane of the mitochondria

B. To change the shape of ATP synthase

C. To form nitrogen

D.To from carbon dioxide

E. To from water


Published Paper 1: Scurvy Dog



Scurvy is caused by a deficiency of vitamin C (ascorbic acid). The way in which this occurs is quite fascinating and as a result peaked my interest. As a result, this was the topic I have chosen for my first published paper. The following will include a summary of the key aspects of the paper followed by my opinion about the paper.

Smith A, Di Primio G, and Humphrey-Murto S. 2011.“Scurvy in the developed world.” US National Library of Medicine National Institutes of Health. Accessed April 13, 2013.

Scurvy in the developed world

A 54-year old patient first complained of severe leg pain which prevented her from walking. She also noted red dots on her leg. The patient’s medical history was investigated and magnetic resonance imaging (MRI) of the affected areas was also done. It was only concluded after further questioning on the diet and a test of the vitamin C levels that the patent had scurvy.

The cause of scurvy being due to a vitamin C deficiency and also the sources of vitamin C were also given. This was then followed by statistical evidence of the occurrence of scurvy in developed countries. The clinical finding of scurvy was then investigated where non-specific symptoms such as fatigue, loss of appetite and irritability were outlined. Reasons was then given for the occurrence of the pains suffered by the 54-year old patient stating that the leg and buttocks, were the first regions to be affected due to the elevated hydrostatic pressures present there.

The deficiency of vitamin C was then linked to the occurrence of anemia  Since most of anemia was linked to acute blood loss due to poor collagen production. This weakness of the collagen allowed blood to be lost from structures like the muscles and the joints. Another link to vitamin C deficiency was  folate deficiency as it was stated that most foods that contain high amounts of vitamin C also contain high amounts of folic acid.The use of MRI did not aid in the diagnosis of the deficiency but it was important as it ruled out any other diagnosis. The indicator of scurvy was said to be rapid response to oral vitamin C. The daily recommendation of vitamin C was also given.

Generally, the information was quite informative. This was also since the symptoms of the deficiency was non-specific and could be easily mistaken for many other death related diseases. The information given such as the daily recommendations of vitamin C was also valuable as it could be applied to everyday life.