Archive for the ‘Proteins’ Category

Taken from Accessed on 24 September 2013

African Clawed Frog. (Xenopus laevis)

Hello All!

I am a cell found inside this wonderful creature. My beginnings first starts, by stimulation of the pituitary gland, which kicks off the production of myself and my brothers and sisters. When my dad becomes mature, my role is to get out there and find myself a female companion, with the hopes and dreams into developing and growing into a tall,awesome, figure like my dad.

I have an three sections to my body. My head has an acrosomal cap on the anterior and below has a nucleus, where all my DNA can be found. My acrosomal head, contains enzymes, which I heard is the surest way to a woman’s heart. In the middle, mitochondria can be found, this gives me energy and my tail helps me to about freely.

Any Ideas to what I am ?

Feel free to comment your answers or thoughts on what you think I might be.    🙂

Stay tuned for more exciting news from the Cloaca. [ Huge hint 😉 ]

Brandon. c:


Garvey, N. 2000. “Xenopus laevis” (On-line), Animal Diversity Web. Accessed September 24, 2013 at

Kaplan, Melissa. 1995. Natural History of the Upland Clawed Frog. Accessed on September 24, 2013. accessed on September 24, 2013.


The following is a review on a published article, “The Effect of Enzymes on Digestion.”, by Michael R. Bedford. Please note that his writings dealt with digestion in Birds.

Contrary to popular belief, that nutrients are always fully digested and absorbed in the blood stream, it is very unlikely that they ever do. Nutrients digestibilities vary between different dietary substances, however there are fours processes that help aid with digestibility. These four mechanisms are:

  • Deteriorating the cell wall 
  • Destroying ANF’s (supplements)
  • Supplying the Host’s Enzymes
  • Using intestinal bacteria

Destroying the cell wall.

Taken from www,newscenter.lbl,gov.

In this mechanism, Beta-glucanase, an enzymes, was used to break down the complex cell wall, rapidily allowing amylases and proteases to break down the cell’s content.

Getting rid of the ANF’s.

ANFs’ are supplements such as, non-starch polysaccharides, proteins, and amino acids.

It was observed that Beta-glucanase turned out to be soluble in barley. This was due to the Beta-glucan component being dissolved completely by the endosperm of the cell wall. ANF’s create viscosity, which reduces the effect of enzymes. Enzymes used to reduce intestinal viscosity are believed to improve digestion in the intestinal tract.

Viscosity. Taken from

Supplying the Host’s Enzymes.

Latest investigations has lead researchers to believe that the digestive tract may not have adequate enzymatic and absorption capacity to deal with all kinds of diets. However, work done by Bedford and Classen, proves that by adding the host enzymes, through means of supplements do in fact increase the rate at which these substances are digested.


Microbial presence?

The are millions of microbes present in your digestive tract. These microbes aid in digestion by breaking down the digestive substances to feed their own needs and produce, in some cases, helpful by products. Evidence to support the presence of microbes in our digestive tract is due to the presences of their by products in faeces.

Bacteria on the walls of the intestines


Bedford. Michael. R. 1996. ” The Effects of Enzymes on Digestion.” The Journal of Applied Poultry Research. Applied Poultry Inc, 1996. Accessed on April 11 2013.

Classen, H.L, T.A. Scotl, G.C. Irish, P. Hucl, M, and M.R Bedford, 1995.”The relationship of chemical and physical measurements to the apparent metabolize energy (AME) of wheat when fed to broiler chickens with and without and enzyme source”.Proc. of 2nd European Symp. on Feed Enzymes, Pages 65-77 Noordwijkerhout, NL. Accessed on April 11 2013.


They do, in fact there are four levels of protein structures: primary, secondary, tertiary and quaternary.

Primary structure of proteins.


Fredrick Sanger was the first scientist to discover the primary structure of proteins, by looking at the protein, insulin. The specific sequence of amino acids in a polypeptide chain is known as the primary structure of proteins. Peptide bonds are the only bonds involved in this sequence.

Secondary structure of proteins.


Secondary proteins, are the shape taken up by the polypeptide chain due to hydrogen bonding. The two most common shapes of secondary proteins are the α-helix and the β-pleated sheets.

An α-helix chanin twist every 3.6 amino acid. It is formed due to the formation of hydrogen bonds  between the CO of one amino acid to the NH of the fourth amino acid.

β-pleated sheet are formed among adjacent polypeptides chains. Like α-helices, hydrogen bonds form between the CO and NH of neighbouring chains, which results in a stronger, yet less elastic structure.


Tertiary structure of Proteins.

Three types of bonds, formed between R-groups, are responsible for the shape of these proteins. These bonds are hydrogen bonds, ionic bonds, and disulphide bonds.

Hydrogen bonds, most common, is formed when an electronegative oxygen is attracted to the electropositive hydrogen of another R-group.


Ionic bonds are formed between an charged amino acid and carbonyl group.


Disulphide bond is a covalent bond formed through oxidation of two -SH groups.


These bonds cause proteins to fold into compact, globular shapes. These proteins are soluble and are called globular proteins, for example, insulin is a globular protein.

Note: Proteins such as keratin or collagen are insoluble and do not fold into tertiary structures, instead they remain unfolded into non-fibrous structures. These are called fibrous proteins.


Quaternary structure of proteins.

Quaternary structure of proteins is the combination of two or more proteins. An example of this type of structure is haemoglobin, which is a combination for four proteins.


Proteins are huge molecules made up of many polypeptide chains. They are seven classes of proteins. Proteins for storage, channel proteins, structural proteins, proteins for immune responses, enzymes, transport proteins, and receptor proteins. Proteins can be globular, fibrous, or membranous.

Receptor proteins are used to sense stimuli.


Channel proteins aid in controlling molecules in and out of the cell. Channel proteins allows simple diffusion into the cell.

Transport proteins carry valuable resources around the body eg. Haemoglobin transport oxygen.


Structural proteins, cartilage made up of the protein collagen, helps prevent bones from rubbing together and cause damage.

Proteins in charge of immune responses, such as antibodies, fight off infection and foreign contaminants from harming the body.

Enzymes are used to speed up biochemical reactions in the body, that may take too long than life itself.



A peptide bond (C-N) is formed when the α-amino group of one amino acid and the carboxyl group of the other amino acid combines, covalently, via condensation.



Peptides get their name from the peptide bonds between two or more amino acids. They are grouped accordingly to the number of amino acids found in the chain.