CARBOHYDRATES CONTINUED………

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For this part, we looked at the formation of glycosidic bonds, structure and functions of certain di saccharides ,lactose intolerance, structure and function of types polysaccharides.

TYPES OF DISACCHARIDES….
These include:
1) sucrose-glucose+fructose –   non red. sugar
2) maltose-glucose+glucose(both alpha)-   red. sugar
3) cellobiose-Bglucose+Bglucose
4) lactose-glucose+galactose (beta 1-4 linkage)-   red. Sugar

Their functions can be found in the following link/s –   http://www.livestrong.com/article/535273-the-function-of-disaccharides/

LACTOSE INTOLERENCE…….
Lactose intolerance is simply the inability of the body  to produce enough lactase to break down amounts of lactose and it is the excess lactose which causes the problem. The excess lactose attracts water and causes bloating and diarrhea. Also bacteria decompose lactose to give off gas and acid in the stomach…well we can just imagine what that gas is right…lol…

TYPES OF POLYSACCHARIDES……

1)Starch-an energy store in plants
-a polymer of alpha glucose
-stored in the form of grains
-compact and insoluble molecule
-minimises osmotic effects

Starch composes of a mixture of TWO types of chains formed by alpha glucose:
1)Amylose-
-long unbranched chains of glucose forming 1-4 glycosidic bonds
-chains take up a coiled /helical form as each monomer has a bulky side group which has to be accomodated
-forms 20% of starch
-the end of the chain where an anomeric C is not involved in a glycosidic bond is the reducing end

2)Amylopectin-
-these are branched chains formed from glucose condensed by 1-4 and 1-6 glycosidic bonds
-coiled chains may contain around 1500 monomers with branches every 24 units
-forms 80% starch

2)Glycogen-an energy store in animals and fungi
-branched chains of alpha glucose condensed to form 1-4 and 1-6 glycosidic bonds
-chains may consist of 10-15 units
-more branched than amylopectin
-insoluble
-seen as small granules suspended in the cytoplasm of cells
-found especially in liver and muscle cells
-since the chains are so short ,they can be hydrolysed rapidly for an animal’s urgent needs.

3)Cellulose-structural compound in plants
-major component of lant cell walls
-formed from beta glucose chains
-alternate molecules rotate through 180 degrees to allow appropriate OH- groups to react forming straight chains
-bulky side groups have to be accommodated for thus leading to straight chains
-hydrogen bonds are formed from adjacent chains between OH groups and O
-parallel cellulose chains form microfibrils and macrofibrils with immense tensile strength and stability.

TO TEST FOR CARBOHYDRATES……

The following link will provide you with the relevant information on the most common tests required for carbohydrates:

http://www.esu.edu/~scady/Experiments/Carbohydrates(summer).pdf

WEEK 2 BIOCHEMISTRY-CARBOHYDRATES!!!

For this week we covered Carbohydrates and as one come across this word, immediately the words sugars and energy should come to mind. After all it is the source of BCninja’s energy and without it how else can I run this blog ???? What was learnt was very basic stuff as it is only level 1 biochemistry so here I go and I hope you understand what is going on….
Carbohydrates have a general formula of  (CH2O)n. Their  functions include transport ,storage,structural and as precursor molecules. We may think that sugars are always good for the body but it isn’t so….remember there are diabetics out there and the main culprit to their problems is glucose levels. So here’s a useful question,

QUESTION: How is this glucose affecting the diabetic??

ANSWER: Well according to http://www.news-medical.net/health/What-is-Diabetes.aspx  diabetes is said to be caused by an elevation in blood glucose levels due to the body not being able to convert excess glucose to glycogen stemming from a lack of the hormone insulin which is produced by the pancreas. there are two types of diabetes- 1 and 2. TYPE 1 diabetes a.k.a juvenile onset/insulin dependent disease (affects only 10% diabetics) is a chronic disease in which there are high levels of sugar in the blood. The affected needs insulin shots after meals to control glucose levels. It can occur at any age mostly in children or young adults. One cause of this is theorised to be an autoimmune disorder which destroys the insulin producing islet cells of the pancreas and being genetically caused, can be passed on to others. Type 2 diabetes is the more common one affecting the rest 90% diabetics.Due to lack or insufficiency of insulin there is high blood glucose in diabetes. Excess glucose in the blood can damage the blood vessels. This leads to several complications like heart disease, kidney damage, nerve damage, eye damage and blindness, impotence and stroke.Diabetes, when not controlled, may raise the propensity for infections.

For an informative video on Diabetes click the following link : https://www.youtube.com/watch?v=dZSnlo3W-3Y   ……… if that one is too good for you try this one (srsly, (-_-) )…….https://www.youtube.com/watch?v=jHRfDTqPzj4

SOME THINGS TO NOTE:
-Complex sugars also form dietary fibre.
-They form  sugars according to the amount of sugar molecules attached to each other giving rise to : 1)monosaccharides-single sugar molecule e.g trioses,tetroses,pentoses and hexoses, 2)Disaccharides-two covalently linkedmonosaccharides, 3)Oligosaccharides-a few linked and  4)Polysaccharides-chains of polysaccharides.

ALDOSES AND KETOSES

Monosaccharides can either be an aldose(-CHO) or ketose(-R-C-=O-R-) based on the presence of an aldehyde or keto group. An easy way to indentify them is when the carboxyl group is at the end of the molecule..it is an aldose but if the carboxyl group it between two other carbons (usually at carbon 2) it is a ketose.
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The Aldo- or Keto- prefix can govern the name of the sugar it is attached to according to the group attached to it for e.g Glyceraldehyde- a aldotriose or Dihydroxyacetone-a ketotriose.*Note-a very important definition that I learnt from my lecturer for carbohydrates is as follows-Carbohydrates are aldehyde or ketone derivatives of polyhydric alcohols classified as mono,di,oligo and polysaccharides.

More about aldoses and ketoses: http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch25/ch25-2-4.html
D VS L DESIGNATIONS FOR THE ASYMMETRIC,ISOMERIC CARBONS

An assymetric/chiral carbon is one which has 4 different groups attached to a central carbon. The D and L designation just depends on which side the OH group is attached to on the chiral carbon. If on the left, it is an L designation and vice-versa. This D or L designation is for molecules of the same type such as glucose and for those with more than 1 assymetric carbon such as glucose (which has 4) ,the name is given according to the carbon furthest  from the aldehyde or keto group.
-D and L sugars are mirror images to each other
-the number of stereo isomers is given by 2^n where n=no. of assymetric carbons e.g if n=4 then 2^n=16

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AN EPIMER??

This is the first time I came across this term but it is pretty simple,it just means two sugars that are similar to each other except for the configuration around 1 carbon.

DL-Glucose.svg

CYCLISATION IN SUGARS…

Hexoses and Pentoses tend to form cycle ring structuresby forming hemiacetals and hemiketals. These in turn can be either alpha or beta.
-6 membered ring-pyranose
-5 membered ring-furanose

Video on cyclisation :  https://www.youtube.com/watch?v=F2QDNRcd3E0

As I said…easy stuff nothing to figure out. Well I hope this post was of good use to any of you and I assure you people the links posted here are very helpful and I use them to aid in my studies…keep training my fellow NINJAS!!! -.-

WEEK 1 OF BIOCHEMISTRY : THE CELL!!!

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This post may be a bit late but it was due to difficulties in setting up and organising the blog…so I am sorry for the delay in providing this piece of information on the cell. It is a relatively easy topic with nothing to really figure out but more of a memory type of task and since I am one for relying mostly on memory I found this topic to be very easy J

ROBERT HOOKE DISCOVERED THE CELL!
So what is a cell ? you may ask…well a cell can be described as the smallest unit that is capable of surviving on its own.

This lecture contained some important bits of information that I did not know anything of and as I said nothing to figure out..just memory stuff..First time I ever came across the words Dialister Pneumosintes which is a tpe of bacteria that stands for a representation of the smallest limit to which a cell can be to exist on its own (.5*.5*1.6micrometers). It is said that any cell smaller than this size would not be able to make enough DNA to survive .
BUT….viruses are much much smaller than these bacteria so how can they survive??what would allow them to be smaller??
ANSWER:

CELL SIZE :

Surface to volume ratio limits the size of a cell. As cell size doubles there is 8 times as much volume but only 4 times as much surface area. This is sown in the following link :

The rate of diffusion slows down which ultimately kills the cell L either by being poisoned by wastes of starvation.

All living cells fall into two broad categories i.e Prokaryotes and Eukaryotes and as university level students the distinction between the two should be already known. Well the difference is mainly due to the presence of a nucleus or not. Other differences are :

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Now here are common structures found in Prokaryotic cells and Eukaryotic cells :

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Basically the rest of this lecture consisted of descriptions of cell organelles so to save time here are links leading to feasible definitions for each one:

1)cell wall-  http://library.thinkquest.org/C004535/cell_wall.html  and http://library.thinkquest.org/12413/structures.html
2)cell membrane- http://library.thinkquest.org/12413/structures.html
3)cytoplasm- http://biology.about.com/od/biologydictionary/g/cytoplasm.htm
4)nucleus- http://biology.about.com/od/geneticsglossary/g/Nucleus.htm
5)E.R- http://library.thinkquest.org/12413/structures.html

6)ribosomes- http://library.thinkquest.org/12413/structures.html
7)S.E.R- http://biology.about.com/b/2011/06/03/what-is-the-endoplasmic-reticulum.htm
8)golgi apparatus- http://library.thinkquest.org/12413/structures.html
9)lysosomes- http://library.thinkquest.org/12413/structures.html

10)nucleoid- http://en.wikipedia.org/wiki/Nucleoid

11)proteasome- http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/Proteasome.html
12)peroxysome- http://www.ncbi.nlm.nih.gov/books/NBK26858/?redirect-on-error=__HOME__
13)mitochandria- http://library.thinkquest.org/12413/structures.html
14)cytoskeleton- http://library.thinkquest.org/12413/structures.html
SOMETHING TO NOTE ABOUT RIBOSOMES!!!

*NOTE-S refers to sedimentation coefficient i.e. how fast the ribosome move in a centrifuge. This gives the difference between ribosomes

FOR 70S RIBOSOMES-        

– found in prokaryotes
-divided into 2 subunits  that is.. a larger 50S + smaller 20S subunit.
-70s ribosomes move slower than 80s ribosomes in a centrifuge

 

FOR 80S RIBOSOMES-

– found in eukaryotes
divided into a larger 60S + smaller 40S subunits
-moves faster than 70s ribosomes in a centrifuge

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LASTLY, we touched a bit on the ENDOSYMBIOTIC THEORY. This theory in a nutshell describes the origin of chloroplasts and mitochondria in cells as a result of endocytosis.
The following link completely describes this theory as well as gives examples of evidence for the validity of this theory..

http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter4/animation_-_endosymbiosis.html

Thank you for viewing and please do add whatever relevant info. you may have in the comments section….*ninjaman disappearrr……..lol