The Anfinsen’s Experiment

Good morning people. I know you must be asking what is this person doing up so late writing a blog? Is she in love with this blog or has she some what become attached. Well I beg to differ, I do this because the learning of biochemistry is fun and the learning and discovery of biochemistry must go on!!!! (LOL come on don’t look at me like I am lying)

So we were doing proteins and I learned this new concept called the Anfinsen Experiment. This experiment was used to prove that the information which is required for the 3d structure of a protein is contained within the primary structure ( the amino acid sequence of the protein).

This was determined by an experiment. I would aim to describe this experiment to you:
The protein which was used was an enzyme ribonuclease. GnHCL and mercaptoethanol was added to the protein. This was to denature the protein. the GnHCL is an example of a chaotrope and disrupted the hydrophobic interactions within the tertiary structure. A chemical which could have replaced the GnHCL is urea. Even though the hydrophobic interactions are the main reason for the 3d structure other bonds are prensent within the 3d structure. The strongest bonds which are present are di-sulfide bonds.

Di-sulfide bonds result from the oxidation of two cysteine molecules in order to form one cystine molecules. The mercaptoethanol is added to reduce the disulphide bonds which was cause the protein to unfold completely.

Now protein folding will not be present as the bonds which enabled these folding have been reduced. The solution was then placed in a dialysis tubing. This tubing would contain many small pores which would allow the smaller molecules to pass through. These small molecules would be GnHCL and mercaptothanol. However the unfolded proteins would remain inside the tubing as it is too large to pass through. Once the solutions which promote the breaking of bonds are removed the protein refolds into the 3d structure.
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From this I was wondering if possibly the body could contain a mechanism which could remove the substances which cause the denaturation of enzymes? I know its a long fetched thought as the body is not perfect, but I am off to research that one.

The Endosymbiotic Theory

Hello once again. So a topic which has never been thought in class but always pops up on an exam is the endosymbiotic theory. So I have decided to research it and try and explain it. So here it goes:

The endosymbiotic theory was first proposed by Lynn Margulis in the 1960’s. What the theory basically says is that the mitochrondria and choloroplast was a result of endocytosis. Endocytosis is the progress by which cells ingest substances such as other cells are taken into the cell. This leads to Endosymbiosis where the cells which have been engulfed mutally live together with parent cell without being digested.

The theory went on to state that chloroplast was a result of endocytosis of an photosynthetic bacteria while mitochrondria was a result of the endocytosis of aerobic bacteria. The allowed the cells to be able to exist in aerobic environments.

endosy

The theory suggested that anerobic bacteria which did not use oxygen in order to obtain energy ingested aerobic bacteria. Aerobic bacteria requires oxygen while anerobic bacteria is poisoned by oxygen. This proved very useful for both the anaerobic and aerobic bateria. The anaerobic bacteria would ingest food and protect the aerobic symbiote while the aerobic bacteria would handle the case of oxygen being toxic to the anaerobic bacteria.

symb

The result of this symbiotic theory was double membrane organelles ( the mitochrondria and chloroplast). The inner lipid bilayer is the bacterial cell’s plasma membrane and the outer lipid bilayer is from the cell that engulfed it.

So I hope that I have helped once again.

Peace out!

Cells Part 2

Hello! So countinuing on the topic of cell ( which i clearly forgot).( I can not believe that i forgot something as important as this!) Anyway enough regrets and more blogging.

So something else that I learned over the cell topic was the a new organelle; the cytoskeleton. For years in school I have been hearing persons refer to cytoskeleton, cytoplasm and the cytosol, but honestly I thought that they were all the same thing and just fancy names for the same thing. TODAY I SHALL BECOME A WOMAN AND CORRECT MY MISTAKE.

So the cytoskeleton is like the backbone of the cell. It is made up of microtubeles or microfilaments thats give a eukaryotic cell a characteristic shape. The cytoskeleton also transports organelles from one part of the cell to another.
cytoskeleton

The cytoplasm is the protoplasm within the living cell. The cytoplasm comprises of the gel like substance in the cell and the organelles present in the cell. Some scientist also say that the cytoplasm refers to the gel like substance in a cell and each organelle except the nucleus.
ouch

The cytosol is simple the aqueous component of the cell. It is referred to as the intracellular fluid or cytoplasmic matrix.
cytosol

So I hope that I have made this very clear. I finally get to sleep at night and assure myself that I no longer confuse the terms.

The Cells part 1

Hey good morning,
I have been looking over some of my post and I seemed to have forgotten one of the most important concepts of biochemistry. It was the first topic done in class and I never wrote about it. Yes you got that right; CELLS. Yes I know what you are saying! CELLS? That’s like primary school stuff right. I mean come on who does not know about cells. So I will not spend much time on the topic. I will break this post up into two , so that information can be digested at a slower rate.

So we went over basically all the main details of cells. That they were the smallest unit of life and that they were made up of many different components and that we first had prokaryotes and then eukaryotes came about ( I will also highlight how this happened in another blog). So as I was saying we did all of these basic stuff, it was really like a division of stuff that we learned at college.

However, something new stuck out at me. This was what limits the size of a cell. I was puzzled for some time by this question. When my lecturer asked it, I was really lost. Never had I thought about what limits the size of cells. So I set myself on some research and the next day it was confirmed in class.

How small a cell gets can be limited by the amount of DNA that the cell needs to survive. These cells have to have enough enzymes in order to catalyse all the functions needed to stay alive. From lecturer notes i found that the smallest cell was the Dialister pneumosintes and this is only 0.5*o.5*1.6 micrometres (seen below). This is currently known as the smallest bacteria.Please bear in mind that viruses are much smaller than bacteria.

dialister pneumosintes

How large a cell can get is limited by the surface area to volume ratio. As cell size increases the volume also increases. By this products of diffusion take a longer time to reach some components of a cell. So as size increases the ratio of surface area to volume ratio decrease.This means that with very large cells some products may not be able to diffuse fast enough and a build up of these products may posion the cell.

So I found these topics very interesting. I hope that I gave someone out their some clarity! Over and out people!
germ relationship go bad

Multiple choice 2

Hey whazzzz up? So I had a quiz today and I think its only fair that I give you a quiz also. Know some of my class mates might be groaning and saying that’s unfair :(. But its okay. I will try and make it as easy as possible! So here we go:

thinking cap

Select the correct multiple answer using ONE of the keys A, B, C, D or E as follows:
A. 1, 2 and 3 are correct
B. 1 and 3 are correct
C. 2 and 4 are correct
D. only 4 is correct
E. all are correct

During Glycolysis which of the following are consumed:

1. 2 ATP

2. 2 NAD+

3.2 Pi

4. 4 ADP

 

Which of the following enzymes are present in the pay off phase

1. Pyruvate Kinase

2. Pyruvate dehydrogenase

3.Enolase

4.Phospho-glycerate isomerase

 

Which of the follwing enzymes are present in the first two priming reactions

1. Phosphohexose isomerase

2.Hexokinase

3.Triose Phosphate isomerases

4.Phosphofructokinase-1

 

Which of the following enzymes is considered the most regulated enzymes?

1.Hexokinase

2.Triose Phosphate isomerases

3.Phosphofructokinase-2

4.Phosphofructokinase-1

 

Which two enzymes take part in substrate level phosphorylation?

1.Phospho-glycerate Kinase

2.Triose Phosphate Isomerase

3.Pyruvate Kinase

4.Pryuvate dehydrogenase

 

Which of the following substances are present in the linkage reaction?

1.CoA-SH

2.FAD

3.Lipoate

4.TPP

 

Which of the following are considered fermentation reactions:

1.Pyruvate to Lactate

2. Pyruvate to Acetyl Co-A

3.Pyruvate to ethanol

4. Glucose to pryuvate

 

Which of the enzymes use TPP as a cofactor?

1. Transketolase

2. Pyruvate Decarboxylase

3. Pyruvate dehydrogenase

4.lactate dehydrogenase

 

Which of the enzyme  is an isozymes?

1. Triose Phosphate isomerase

2.Pyruvate dehydrogenase

3.Pepsin

4.Hexokinase

 

Which of the following belong to the class lyases?

1.Hexokinase

2.Glyceraldehyde 3-phosphate dehydrogenase

3. Phospho-glycerate kinase

4. Aldolases

 

So have a crack at it and I would tell you how you did.

keep calm