Good luck biochem peeps

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I just wanna say goodluck to everyone that’s doing the biochem course 1362! 🙂 It was fun getting to know you all better!

oh and i just wanted to post a song that i like…hope you guys like skrillex 😀
https://www.youtube.com/watch?v=YJVmu6yttiw

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Multiple choice questions!

Now don’t get scared…it’s going to be simple 😛

Multiple Choice Question 1

Choose one of the options to answer the following question

a) I,II,II
b) II,III
c) I,II
d) I,III

1) The cofactors in the reaction;

Pyruvate à Acetyl-CoA

are:

I- CoA-SH
II- NAD+
III- TPP,Lipoate,FAD

 

 

 

 

Multiple Choice Question 2

1) Which enzyme works best at a pH of 2?

a) Trypsin
b) Catalase
c) Pepsin
d) Lipase

Glycolysis

What is Glycolysis?
It is the process whereby one molecule of glucose is broken down to form 2 molecules of pyruvic acid by the body. Glycolysis is also referred to as the citric acid cycle. It is a thermodynamic reaction since it releases energy
https://i0.wp.com/homepages.ius.edu/GKIRCHNE/glycolysis.jpg

http://biology.about.com/od/cellularprocesses/a/aa082704a.htm
the link above shows the steps of glycolysis in an easy to understand format!

Fates of pyruvate
http://www.youtube.com/watch?v=PsAFTx8g_cM
This video was very in depth and interesting 🙂 it was very helpful in my understanding of the topic! hope it proves to be the same for you as well! 

Another publish paper review

Why so moody?

 

According to the article “Second messenger/signal transduction pathways in major mood disorders: moving from membrane to mechanism of action, part I: major depressive disorder” mood disorders have been related to the modulation of monoaminegenic and amino acid receptors at the plasma membrane. Monoaminergenic refers to neurons that secrete monoamine neurotransmitters (serotonin, norepinephrine, dopamine). The inhibition of these receptors alters the neurotransmitters levels. The effects of the inhibition are not outwardly expressed immediately. The time lag however disturbs the intracellular neuroplasticity in the mechanism of the action of mood stabilizers and antidepressants. Neuroplasticity refers to the brain’s ability to reorganise itself by forming new neural connections throughout life. When the intracellular second messenger is adjusted it affects the neurotrophic pathways that are needed for monoaminergenic and amino acid-based treatments.  Major Depressive Disorder and other pathophysiological studies have been aimed at intracellular mediators. In the past the intracellular dysfunction appears important in the pathophysiology.

 

 

Sources:
http://www.ncbi.nlm.nih.gov/pubmed/23462230 http://www.ncbi.nlm.nih.gov/pubmed/?term=Second+messenger%2Fsignal+transduction+pathways+in+major+mood+disorders%3A+moving+from+membrane+to+mechanism+of+actionImage%2C+part+II

Amino Acid and Proteins

My last post was on a publish paper, now moving on…

Amino acids contain a carboxyl group, hydrogen, a NH3+ and an R group all connected to one carbon. There are many different amino acids, they differ with respect to their R group.  Amino acids are categorised based on their R groups, There are:

  • Non Polar Aliphatic R groups
  • Polar uncharged R groups 
  • Aromatic R groups
  • Positively charged R groups
  • Negatively charged R groups

As you can see there are lots of different R group types which means that they give rise to many different amino acids! The names of these amino acids are abbreviated to help us remember and prove to be useful! There are 20 amino acids that make up most of the proteins in your body. Out of these 20 amino acids, there are essential and non-essential amino acids.
Essential amino acids can be separated in complete and incomplete proteins. 
To test for amino acids one uses the Ninhydrin Reaction.

LAB WORK!
The ninhydrin reacts with amino acids, forming a purple solution. Testing for protein involves the Biuret Test. The biuret reagent is light blue
 containing Cu2+ ions in an aqueous form. A purple colour is formed when biuret is mixed with a protein solution. 

Peptide bond… 🙂

It is formed between the alpha amino group of one amino acid and the alpha carboxyl group of another amino acid. Polypeptides/proteins are formed when more than 25 amino acid groups are linked together via peptide bonds.

There are globular and fibrous proteins. A globular protein has a variety of secondary structures. They are water soluble and have dynamic roles for example; enzymes. A fibrous protein, such as collagen, has one dominant structure,rod shaped, poor water solubility and serves in functional roles. 

There are 4 levels of protein structure:

  • Primary
  • Secondary
  • Tertiary
  • Quaternary

Click the link below to find out more!! 😀
http://www.youtube.com/watch?v=ll4xZVFgo74

Denaturation Of proteins
http://www.youtube.com/watch?v=SUCgAxI8rhg
The link above was very interesting! hope u enjoy!

Mary Jane good for the brain?

My publish paper review! 

Cannabis commonly referred to as marijuana, mary jane, pot and many other names is a drug used by a lot of people worldwide, mainly recreationally. It is obtained and prepared from the flowering plant Cannabis. It is illegal and is considered as drug abuse as it can have a negative impact on the body and one’s health. According to the article published on Newscientist.com 13th October 2005, entitled “Marijuana might cause new cell growth in the brain” suggests that marijuana can be good for the brain. In the research conducted by Xia Zhang of the University of Saskatchewan, Saskatoon, it was found that there is a synthetic chemical, HU210, that resembles an active ingredient found in marijuana that makes new cells grow in the brain of rats. When the rats were given 2 doses of the chemical for 10 days, the cell growth in the brain increased as well as the neurogenesis in the hippocampus by 40%. The hippocampus is a specific area in the brain that is involved in memory forming, organizing and storing. Other drugs that are used recreationally have an adverse effect on the growth of new cells in the brain.  The rats were also tested for behavioural changes, this was due to a previous study which indicated the medication Prozac also caused new cell growth which had an anti-anxiety effect. The rats that were treated with the cannaboid exerted fewer signs of anxiety and depression that the rats who were not treated. When the treatment was stopped via x-rays, the effect was not the same, it had diminished and it was suggested that the cell growth was responsible for the behavioural pattern. A study conducted by Barry Jacobs showed that when rats were given THC, a cannaboid found in marijuana, there was no neurogenesis detected despite the dosage or period of time. THC and HU210 do not have the same effect on the growth of cells, that is, on that particular species of rodent, it is unknown for other species as well as for humans.  More research is being done to determine whether cannaboids could be used to treat depression in humans. 

Source : http://www.newscientist.com/article/dn8155-marijuana-might-cause-new-cell-growth-in-the-brain.htmlImage

More on enzymes!

The links posted under each factor is a concise easy explanation along with diagrams to enhance understanding! It is very helpful! 😀 

ON TO SOME MORE EXCITING STUFF!

INHIBITION!!!!! 

What is an inhibitor??  Well in with respect to enzymes, it is any substance that can dminish the velocity of an enzyme catalysed reaction. Inhibition can be either reversible or irreversible. 

Reversible inhibitors bind to enzymes through non covalent bonds while irreversible inhibitors bind to enzymes through covalent bonds. 

There are 4 types of inhibition!!!!

  • Competitive
  • Non Competitive
  • Uncompetitive
  • Mixed Inhibition


    HALT!!!
     BEFORE YOU CONTINUE YOU SHOULD FAMILIARIZE YOURSELF WITH THE MICHEALIS-MENTEN CURVE AND THE LINE WEAVER BURK PLOT!

COMPETITIVE INHIBITION! 

The inhibitor binds reversibly to the same site that the substrate would normally occupy and it competes with the substrate for the site.

The effect on Vmax
The effect of ca competitive inhibitor can be reversed by increasing substrate concentration. When [S] <– Substrate concentration….. is high, the reaction velocity reaches the Vmax observed in the absence of an inhibitor. 

The effect on Km
A competitive inhibitor increases Km for a given substrate. In the presence of an inhibitor more substrate is needed to achieve 1/2 Vmax. 


The Michealis Menten curve is on the left side while the lineweaver burk plot of competitive inhibition is on the right side.

NON COMPETITIVE INHIBITION! 

It occurs when the inhibitor and the substrate bind at different sites on the enzyme. 

Effect on Vmax
Non competitive inhibitors cannot be overcome by [S]. It decreases the Vmax of the reaction.

Effect on Km
They do not interfere with the bonding of substrate to enzyme.

Michealis Menten curve on the left while lineweaver burk plot is on the right. 

UNCOMPETITIVE INHIBITION

The inhibitor binds only to the enzyme substrate complex at a separate site from the substrate active site not with the free enzyme

Lineweaver burk plot

MIXED INHIBITION!

The inhibitor binds at a separate site from the substrate active site to either the free enzyme or the enzyme substrate complex. Km may be increased or decreased whereas Vmax is always reduced. 

ALLOSTERIC ENZYMES!

They have more than oe active site which cooperatively bind substrate molecules such that the binding of substrate at one active site induces a conformational change in the enzyme which alters the affinity of the other active sites for substrates

click the blue stuff below for more info!
http://www.youtube.com/watch?v=C2jnP9SvFJE