High Density Lipoprotein Cholesterol Levels Biology Essay

Triglycerides, cholesterin and high and low denseness lipoproteins affect the manner the organic structure maps ; their concentrations vary amongst every person. This experiment will find the concentration of these four elements in a human blood sample utilizing enzymatic reactions.

Methods: Three processs were carried out utilizing samples of fasting blood. The absorbency readings were recorded and calculated to compare values of triglycerides, cholesterin and HDL degrees within the blood.

Consequences: Recorded utilizing a spectrophotometer ciphering the moving ridge length of the enzymatic reaction. This is so calculated against the concentration of criterion and the standard moving ridge length to find the other all concentration of triglycerides, cholesterin and high and low denseness lipoproteins.

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Decision: The consequence obtained from the experiment show that the participant has healthy degrees of cholesterin, triglycerides, HDL and LDL cholesterin, which match the optimum degrees.


Fats, or lipoids, are indispensable to the organic structure ‘s diet as they are an of import energy beginning coupled with proteins and saccharides. There are many sorts of lipoids that exist within the organic structure ; nevertheless this experiment focuses on triglycerides as these are the common shop of fat in nutrient and the organic structure.

Triglycerides are made up of one glycerin molecule and three fatty acid concatenation which are attached through desiccation synthesis making ester bonds. They have three maps within the organic structure ; foremost they provide an energy beginning, when needed triglycerides are broken down by hydrolysis. Due to flesh out sedimentations under the tegument, triglycerides besides serve as insularity for the organic structure, assisting cut down the loss of organic structure heat. Finally, they besides provide protection to critical variety meats, by making a bed of fat around a delicate organ.

Cholesterol is another signifier of lipid and is a major participant in assisting the organic structure map usually. It is present in the outer bed of every cell and is needed to keep their plasma membranes, every bit good as promote cell grow and division. Cholesterol determines which molecules can and can non go through through the cell membrane, every bit good as helping the production of gall acids which help to breakdown ingested nutrients. It is obtained in two ways: through dietetic consumption of animate being merchandises, and by synthesis within the liver.

Lipoproteins are molecules that carry triglycerides and cholesterin within the blood ; they are any complex or compound that contains both lipoids and proteins. High Density Lipoproteins ( HDL ) and Low Density Lipoproteins ( LDL ) are the two major types of lipoproteins. HDLs are made up of more proteins, therefore are denser, these are known as good cholesterin as it removes cholesterin from the arterias to the liver where it is either broken down or converted into waste merchandises for elimination. LDLs are known as bad cholesterin as they carry it to off from the liver to the peripheral tissue, nevertheless if excessively much is transported it builds up on the wall of the arterias which can take to jobs such as high blood force per unit area and bosom disease. ( Christian Nordqvist, 2009 )

As cholesterin is taken in through the diet, the participant must fast for 12 hours to let the measurings of cholesterin to merely be the cholesterin produced by the liver. These measurings are so calculated and measured against the optimum scopes of concentrations. ( See appendix 1 for optimum cholesterin degrees )


One participant volunteered to take portion in the survey. A sample of blood was removed from the participant after a 12 hr fasting period ; this sample was so spun in the extractor to divide the serum from the ruddy blood cells in readying for the lab.

Measurement of Blood Triglyceride Levels

Label four cuvettes as space ( 1 ) , standard ( 2 ) , sample ( 3 ) , and unknown ( 4 ) , puting 1 milliliter of reagent solution R1 in each one. In add-on to this, add 10 µl of the standard solution into cuvette 2, 10 µl of the sample ( serum ) into cuvette 3, and eventually 10 µl of the unknown solution into cuvette 4. Once these have been mixed, by gently inverting them several times, leave at room temperature for 10 proceedingss to let the reactions to take topographic point. Ensure that the spectrophotometer is set to a wavelength of 500 nanometers, so topographic point cuvette 1 into the machine and zero the value. Then place each cuvette into the spectrophotometer guaranting that it is set to aero each clip utilizing the clean cuvette. Repeat the readings for each cuvette ( 2, 3, 4 ) three times in order to derive an mean optical density reading.

Measurement of Total Cholesterol Levels in Blood Serum

As earlier, label cuvettes blank ( 1 ) , standard ( 2 ) , sample ( 3 ) and unknown ( 4 ) , puting 1000 µl of reagent solution R1 into each one. In add-on add 10µl of distilled H2O to cuvette 1, 10 µl of cholesterin criterion to cuvette 2, 10 µl of blood serum to cuvette 3 and 10 µl of unknown solution to cuvette 4. Let these to stand at room temperature for 10 proceedingss, one time they have been gently inverted. Guarantee the spectrophotometer is set to a wavelength of 500 nanometers and so reiterate the process as earlier, guaranting that the spectrophotometer is zeroed between each sample.

Measurement of HDL – Cholesterol Concentration in Blood Serum

Once once more label 4 cuvettes clean ( 1 ) , standard ( 2 ) , sample ( 3 ) and unknown ( 4 ) , puting 1000 µl into each one. In add-on, add 100 µl of deionised H2O to cuvette 1, 100 µl of standard solution to cuvette 2, 100 µl of the blood serum to cuvette 3 and 100 µl of unknown solution to cuvette 4. Gently invert these and leave at room temperature for 10 proceedingss. Transport out the same process as before utilizing the spectrophotometer to enter absorbency readings on a wavelength of 500 nanometers.


( To see the completed absorbency tabular arraies and computations carried out, see appendix 2 )

Measurement of Triglyceride Concentration in Serum


0.132/0.262 ten 195 = 98.24 mg/dl

To acquire the free glycerin we have to subtract 10mg/dl from the above figure conveying it to 88.24 mg/dl.

Graph 1.1

Measurement of Total Cholesterol Levels in Blood Serum


0.187/0.294 ten 196.86 = 125.21 mg/dl

Figure 1

Measurement of HDL- Cholesterol in Serum


0.236/0.806 ten 196.86 = 57.64 mg/dl

Figure 2

Calculation of LDL – cholesterin


125.21 – ( 88.24/5 ) – 57.64

125.21 – 17.648 – 57.64 = 49.922mg/dl

Figure 3


As expressed before, cholesterin is an of import constituent in assisting the organic structure map decently, nevertheless it is indispensable to hold the right degrees of cholesterin otherwise there is hazards of shots, bosom disease and coronary artery disease. Reviewing the consequences gathered from the experiment, the participants ‘ triglyceride degrees fit into the desirable class demoing that their organic structure is devouring sufficient sums of saccharides and fats within their diet, leting any extra sugars non used for energy to be converted to LDL cholesterin by insulin within the liver. The degrees of LDL and HDL cholesterin within the blood of the participate tantrum into the optimum degree for LDL cholesterin and the norm for HDL cholesterin, showing the participant to hold a minimum physique up of cholesterin around the arterias proposing that they are fit and healthy. The degrees of cholesterin consequence alterations in the proteins that are present on the plasma membrane, every bit good as glucose metamorphosis ( Hao, Steven Head, Gunawardana, Hasty, Piston, 2007 ) ; if HDL is excessively low this can class depression in the person ( Psychosomatic Medicine 2000 ; 62 ) . If the single consumes excessively much fatty nutrients rich in sugars, and does non utilize them for energy so there is a build up of LDL cholesterin being converted ; this consequences in cholesterin environing the arterias increasing the hazard of bosom disease. Insulin that is released to equilibrate out the sugars within the organic structure can advance the storage of fat, assisting to promote rapid weight addition and elevated triglycerides ( Hao, et Al, 2007 ) . The participants ‘ entire cholesterin degree is at a desirable phase reenforcing that the degrees of HDL and LDL are equal within the organic structure and do non show a hazard of bosom disease of shot. If the arterias had a high physique up of cholesterin so it will curtail sum of O ( carried by the blood ) acquiring to the bosom, ensuing in thorax strivings and in utmost instances bosom onslaughts ( U.S Department of Health and Human Service, 2001 ) .

Cholesterol is affected by many different factors, physical activity helps to take down LDL cholesterin and increase HDL cholesterin, hence leting more cholesterin to be transported off from the bosom to be converted into gall and excreted, or helps with the map of the cell membrane. Transporting out regular hebdomadal exercising that burns 800 -1200 kcal is recommended to increase HDL to a desirable sum ( Heaner, M. ) ; the participant supports this theory by transporting out regular ( 3-5 ) aerophilic Sessionss a hebdomad, advancing the addition of HDL ‘s. Triglycerides can besides be reduced by 15 to 25 per centum through regular exercising nevertheless the trigger for this is much higher, transcending 2,500 to 3000 Calories to be burnt per hebdomad. In drumhead this survey shows that the participants degrees of cholesterin, interrupt down to HDL, LDL and triglycerides, matches the desirable degrees of a healthy individual, demoing that they have a healthy diet, with regular exercising to avoid the LDL cholesterin and triglyceride degrees from increasing.


In decision, the consequence obtained from the experiment show that the participant has healthy degrees of cholesterin, triglycerides, HDL and LDL cholesterin, stand foring that their organic structure is working right and they are keeping a healthy balanced diet.