PUBLISHED PAPER #2

PUBLISHED PAPER #2

 

Panfoli, Isabella,Daniela Calzia, Silvia Ravera, Alessandro Morelli.2010. “Inhibition of Hemorragic Snake Venom Components: Old and New Approaches”. Accessed April 12, 2013. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153198/

 

 

Snake venoms are mixtures of biologically active proteins, metal ions, peptides and organic compounds. There are over 600 species of venomous snakes which can be classified into several groups. Most of the world’s envenomation’s are due to crotalidae and viperidae venoms. Venoms which affect the cardio-vascular system are classified hemotoxic whereas those that affect the nervous system are classified as neurotoxic.

Hemotoxic venoms contain various enzymes, isoenzymes and non-enzymatic proteins that either activate or inhibit factors that affect hemostasis. Many of the toxins in the venom affect platelet function by inhibiting or inducing platelet aggregation. Phospholipase A2 (Pla2) isoenzymes are responsible for inflammation and can be found in large numbers in both hemotoxic and neurotoxic venoms. Hemorrhages are caused by enzymes degrading proteins and components of the hemostatic system. This can be lethal as the hemostatic system is responsible for stopping bleeding and wound healing, which is the opposite of hemorrhage.

The extract of protein from horses and sheep are used as antivenins as they neutralize the toxins in humans. The administration of these toxins may be risky. Neutralization of toxins using inhibitors in plant extract may be used. Inhibitors of PLA2’s form soluble complexes with PLA2 enzymes, inhibiting their effects. Electric currents can also be used as a neutralizer at low voltages against metalloproteases and PLA2. There are many approaches to inhibit hemorrhagic venom which present advantages as well as disadvantages.

Most people, if not aware of how, know that some snakes possess poisonous venoms which can be lethal. It is known that poison affects the body in a negative way, but I have never known how or why. From this paper I have learnt that venoms are composed of proteins which are responsible for attacks on specific system which, if not treated, will bring down the body from within. I also learnt that inhibitors play a positive role in preventing these damaging proteins and so are the major components in antivenins. This paper may be difficult for someone without a biochemistry, biology or chemistry background to follow. It is also too wordy.

PUBLISHED PAPER #1

PUBLISHED PAPER #1

 

Mattar ,Rejane , Daniel Ferraz de Campos Mazo, Flair Jose’ Carrilho.2012. “Lactose intolerance: diagnosis, genetics and clinical factors”. Accessed April 11, 2013. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401057/

 

Lactose is a disaccharide that makes up the majority of mammalian milk and is also a major source of nutrition for new-borns until they are weaned. It is broken down by the enzyme lactase, which most people are born with, into glucose and galactose. Lactase activity is high at young ages such as birth to around two years old, but begins to decrease rapidly with age in some people(hypolactasia) grouped as “lactase non-persistence”. Those who maintain high lactase activity into adulthood are grouped as “lactase persistence”.

The LCT gene controls lactase persistence and non-persistence. The LCT13910CT and LCT13910TT genes are both found to be associated with lactase persistence, showing that the allele is still dominant in a heterozygous form, allowing the breakdown of lactose. However when the dominant LCT13910T is not present this results in lactose non-persistence, “lactose intolerance”. This may differ in different countries.

Lactose persistence and non-persistence can be tested by checking the body’s glucose and galactose level when lactose is ingested. Galactose metabolism is inhibited with ethanol to determine the glucose rise. A breathe test based on the fermentation of undigested lactose can be used as well as genetic testing.

The by-products of undigested lactose in the intestines, carbon dioxide, hydrogen, methane and short-chain fatty acids result in abdominal pains, flatulence and bloating. It also acidifies the colon which results in diarrhea. These symptoms may also be accompanied with others not related to the gut.

This paper was very in-depth about the topic. It is very easy to be lactose intolerant and not know it can be so complex. One may drink a glass or milk or some yogurt for breakfast and not fully understand why they have and urge to defecate (poop) or fluctuate. I would’ve never guessed that my body’s ability to ingest milk and tolerate it could be associated with my genetics. I would suggest this paper to anyone in need of answers to their milk-stomach related issues.

Enzymes Video Review

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.

The CEll

Cells are the smallest units capable of performing life functions such as replication, growth, metabolism, and stimulus response. The cell was discovered by Robert Hooke in 1665. Cells may differ in their shapes and sizes as a result of their different functions. Cells cannot be too small or they will not be able to make sufficient DNA to sustain life. They also cannot be too large as the surface area to volume ratio decreases and food and waste will not be able to diffuse in and out fast enough, resulting in starvation or the cell being poisoned. The co-founders of the cell theory are Matthias Schleiden, Theodor Schwann and Rudolf Virchow. There are prokaryotes (before nucleus) which lack membrane bound organelles, and eukaryotes (true nucleus) which contain a variety of membrane-bound organelles. The organelles are, in no particular order, the nuclear envelope, ribosomes, plasma membrane, food vesicle, mitochondria, chloroplast, nucleolus, cytoskeleton, nucleus, starch granules, rough endoplasmic reticulum, cell wall, smooth endoplasmic reticulum, thylakoids, golgi apparatus, vacuole, lysosome, plasmodesmata, peroxisomes and glyoxysome. The organelles depends on if the cells are of plants or animals. Organelles that are present in animal cells but NOT plant cells are lysosomes, centrioles and peroxisomes. Those found in plant cells but NOT animal cells are the cell wall, plasmodesmata, chloroplast and glyoxysome. Each of these organelles have specific functions that are necessary for the cell to survive and carry out its duties efficiently. The body depends on cells to function, thereby sustaining life. Cells contain DNA and RNA, there are three organelles that contain DNA, the mitochondria, the chloroplast and the nucleus. In the endosymbiotic theory proposed by Lynn Margulis in 1977, the mitochondria and chloroplast are said to have evolved from prokaryotes to eukaryotes as they contain DNA.
This video was very informative without going into extreme, to-the-core details. It contained clear, well annotated diagrams which were accompanied by knowledgeable explanations. I enjoyed this video, it was easy to take notes and follow, it also allowed me the flexibility to walk away from it and not have to start over when I returned. Even though all the information on cells, like that of the endosymbiotic theory and the co-founders of the cell theory were not included in the same detail, they were mentioned at some point in the video allowing a guide for further research. If I was super lazy i would suggest you put in this information but I am not and I enjoyed doing the research to expand on the points as it broadened my knowledge. In terms of what I enjoyed the most was the endosymbitic theory, even though it was only mentioned in the video, and the step by step on how the golgi apparatus opperates and formation of vesicles.

images