SELF REFLECTION ON LIPIDS

(AQMAL SYABIL BIN ASMADY 72125) 

Things that I have learned in this learning unit (Lipid) is food that is rich in lipids are avocados, cheese, dark chocolate, whole egg, fatty fish, nuts, chia seeds, coconut oil, butter, milk and others. I also learned that lipids have several functions towards our body. The functions are :-
1. Lipids containing hydrocarbon side chains serve as energy stores
2. Lipids in the forms of a bilayer are essential components of biological membranes.
3. Intra and intercellular signalling molecules.
4. Heat insulation
Lipids also produce more energy compared to carbohydrates. This is because it has more hydrocarbon-chain.

I also learned about the differences between saturated and unsaturated triglyceride.

Characteristics	Saturated	Unsaturated
Room temperature	Solid	Liquid
Type of bond	Hydrocarbon (single bond)	Have at least one double bond
Chain	Straight chain	Bent
Low density lypoproten	High LDL	Low LDL
Production	Fat	Oil
Type of acid	Myristic, stearic, palmitic	Lisioleic, oleic, stearidonic

What is glycerolphospholipid and its functions?
Glycerolphospholipid is main component of biological membrane and its functions are regulate the toxic, nutrient, reproduction and signal transduction cell motion and cell to cell interaction.

I have also learned about the important of cholesterol.These are some importance of cholesterol in our body.
1. 20% - 25% of lipids mass are cholesterol in membrane.
2. Maintain the fluidity of the membrane
3. Allow ion/molecule to get in or out.
4. Maintain the integrity (structure) of the phospholipid of the cell membrane.

This is the importance of cholesterol in our diet.
1. Control the salt balance in our body.
2. Metabolic function
3. Sexual function

This is the importance of derivative of cholesterol.
1. Bile salts
2. Steroid hormone
3. Vitamin D

(MUHAMMAD HANIF FIKRI BIN MOHAMAD KHIRUDIN

72417)

For this learning unit, we learned more about fatty acids and lipids. During this class, we were divided into 5 group to discuss about the classified lipids. Dr Hashimatul explained that lipids are biomolecules that are soluble in organic solvents. It also performs three biological function which is it act as energy stores since lipids containing hydrocarbon side chains. Lipids in the forms of a bilayer are essential components of biological membranes. Intra and intercellular signalling molecules. Furthermore, there are two type of lipid, first is non-polar lipids that act as energy storage and the polar lipids act as the basis of bilayers. For more details, lipids are further classified into several groups, fatty acids, triacylglycerols, glycerophospholipids, sphingolipids and isoprenoids. Next move to the Triacylglycerols (TAG). Fatty acid are triesters of glycerol. Most contain two or three different types of fatty acid residues. The TAG have 3 roles, TAGs function as energy storage. The fat content of normal humans allows them to survive starvation for 2 – 3 months. Besides, insulation and the third is Saponification – formation of soaps from TAGs. Next we move to the Glycerophospholipids. Glycerophospholipids are the major lipid component of biological membranes.

Next classified is about the phospholipids. Phospholipids can be degraded at various point, depending on the enzymes used. We move to Sphingolipids. Dr told us that Sphingolipids are major membrane components. They are derivatives of the C18 amino alcohol sphingosine. The N-acyl acid derivatives of sphingolipids are known as ceramides. Some examples of sphingolipids is Sphingomyelins. It contain either phosphocholine or phosphoethanolamine. The myelin that surrounds and insulates nerve cells is rich in sphingomyelines. The Cerebrosides is a head group that consists of a single sugar. Next examples is Gangliosides. Primary components of membranes on cell surfaces and constitute 6% of brain lipids. This gangliosides act as receptors for pituitary glycoprotein hormones that regulate physiological functions. For steroid, cholestrol is the most common steroids in animals and precursors for all other steroids in animals. Steroids hormones serve many functions in animals, as example, it including salt balance, metabolic and sexual functions.

Terpenes are major biosynthetic building blocks within nearly every living creature. Terpenes are derived biosynthetically from units of isoprene, which has the molecular formula C5H8. Its activated forms, isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) are the building blocks. Terpenes have several biological functions which is it can act as color and odors associated with plants (essential oil), vitamin and precursors, visual pigments and chloroplast pigments. Next classification is the Eicosanoids. Eicosanoids are signaling molecules made by oxidation of C20 essential fatty acids (EFAs). Eicosanoids exert complex control over many bodily systems, mainly in inflammation or immunity, and as messengers in the central nervous system. The eicosanoids will act at low concentration and are involved in the production of pain and fever, regulation of blood pressure, blood coagulation and reproduction. There are four families of eicosanoids— prostaglandins, prostacyclins, thromboxanes and leukotrienes.

Last but not least, the lipids soluble vitamins which is the A, D, E and K vitamins. Vitamin A is a group of unsaturated organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids and beta-carotene. Vitamin A play an important role in the visual cycle of rod cells. For vitamin D, it is a group of structurally related compounds that play a role in the regulation of calcium and phosphorus metabolism and the most abundant form in the circulatory system is vitamin D3. Next is vitamin E. Vitamin E is a group of compounds of similar structure and the most active is α–tocopherol and not forget to mention that Vitamin E is an antioxidant. Traps HOO• and ROO• radicals formed as a result of oxidation by O2 of unsaturated hydrocarbon chains in membrane phospholipids. From this class, now we know more about the lipids and the roles of each classification of the lipids. 

(NAZRUL SYAZWAN BIN MOHD NAZERI 72461)

In this learning unit, I have learned about fatty acids and lipids. Although this topic I have already learned it previously, but this time I have learned something new about lipids that I do not know. During the class, we were divided into several groups. The purpose of this groups are to discuss among the members in the group about the topics. Firstly, Dr Hashimatul explained about fatty acids and lipids. Based on the polarity, lipids divided into two which are polar and non-polar. Then, lipids were divided into sub-group which are fatty acids, triacylglycerols, glycerophospholipids, sphingolipids and isoprenoids. Fatty acids were divided into saturated and non-saturated.

Common Saturated fatty acids

Common Non-saturated fatty acids

I also learned about function of Triacylglycerols (TAG). TAG functions as energy storage, insulation and in saponification process. Some of vitamins are lipid soluble. For example : vitamin A, D, E and K.