Tay Yu Liang -71789
Today, the lecture is about lipid.In the group
discussion, we discuss the function of lipid. Lipid is an essential elements as
it bring us a lot of advantages. Take, for example, it act as the energy store,
intra and inter signalling molecules, insulation and from of bilayers. We also
discuss the differences of saturated and unsaturated fat. Through the
discussion, we know that saturated fat is a bad fat as it do not have double
bond and unsaturated fat is a good fat as it has double bond. Saturated fat
will increase LDL which will increase risk of heart disease and the unsaturated
fat will increase the HDL which can remove the other form of cholesterol from
the bloodstream. Besides that, we also discuss the transmembrane protein. There
are two type of transport which involve transmembrane protein. Passive
transport transfer the chemical molecules from high to low concentration which
involve pore protein and carrier protein while active transport involve energy
requirement and involve carrier protein. We also discuss the sphingomyelins,
cerebrosides and gangliosides. All of these three molecules is sphingolipids.
Last but not least, we discuss the signal transduction. This process is very
important as it coordinates our body activities.
From the last class, we had learn about the lipids.
Lipids is a very diverse and have big structure and functions. All of the
lipids are not soluble in water but soluble in toluene ( C7H8). The
lipids are the large or diverse group of naturally organic
compounds that related to their solubility in non-polar organic
solvents. Since lipids are non-polar molecules, their ends are not
charged. Water is polar and lipids are non-polar, so that
means lipids are not soluble in water. The lipid molecules and water
molecules do not bond or share electrons in any way. The lipids just float in
the water without blending into it. On the other hand, lipid can easily
dissolve in toluene. This is because toluene is non-polar compound. Since both
of them are non-polar so that is why they can dissolve together. Toluene
is a very good solvent compared to water, since toluene can
dissolve in many organic compounds.
The functions of lipids are first, they are the
production of the hormones. Other than tht it also act as an insulation which
is to produce heat. Fat also used as a protection. They protect other organs in
the body. The lipids also give importance functions to the living organisms.
They act as a chemical messengers and serve as a valuable energy sources.
Lipids also provide insulation and they are the main component of membranes.
The major of lipids groups includes fats, phospholipids, steroids and waxes.
Waxes are composed by a group of alcohol and fatty acids. For example that
plant have wax coating at the leaves for helping them to conserve of prevent
large amount water loose. Next is phospolipids is made up of groups of fatty
acids, a glycerol component, and both a phosphate group and a polar molecule.
Lipids can be categories into two groups which are
saturated and unsaturated. The differences between this two group is
unsaturated fats is healthier compared to saturated fats. Saturated fat can
cause disease such as heart attack and stroke. The unsaturated fats is good
because it has double bonds so that it has gap between the atoms. Examples for
unsaturated fats are vegetable oils and olive oil. On the other hand,
cholesterol also give benefits to our body system. They are needed to maintain
the quality of phospolipid in our body. In cold they will stay apart while when
hot they will stick together. This is to product a good quality of structures.
They also work to produces the bile acid. In this chapter also we also recall
back about the active and passive transport. The differences between this two
transport is active use energy (ATP) while passive does not required any
energy.
Lipids also can be classes into two which are
terpenes and sphingoipids. Terpenes are exist only in plants. They produce
chemical compound that have smells. For plant, they act as a protection. They
protect it from the predator and at the same time they will try to attract
pollinators by producing smell. Terpenes also used as therapy to helps us keep
relax and release stress. Actually, there are 150 terpenes have been discovered
but only 6 terpenes that commonly found. Examples are limonene and
terperpinonene. Sphingolipids is the major lipid that exist in both animals and
plants. This class have three other types which are sphingomyelins, ganglioside
and cerebroside. Sphingomyelin mostly found in the animals. The head group for
this type is phosphocholine. The next type is ganglioside, it have three sugar
combination for head. Examples are combination of glucose + galactose +
fructose. This type can be found in the neurons. Last but not least is the
cerebroside. The head group consist single sugar or monosaccharides such as
glucose or galactose as a polar group. This type is the important components in
animal muscle and nerve cell membranes. They cn be found in the brain and mylin
sheath. The examples are galactocerebroside and glucocerebroside.
The signal translations is the process which involve
the external and receptor activities. For example the external cell will send
impulse to the target cell then the receptor will react by inform the inside
cell. So the inside cell will form the new signal. The neuron transmitter is
the example for this activity. In conclusion, the application of lipids
are widely used in our surrounding without noticed. So we should stay alert and
try to use this opportunities to maintain the function of lipids in our daily
life.
Siti Aminah Maisarah-72673
During
the last class of Biochemistry, I had learnt about lipid and to simply
summarize all about it ,I gained a lot of new knowledge regarding the function
of lipid, the types of lipids, terpenes and sphingolipids, the importance of
cholesterol ,active and passive transport , and signal transduction. Before
getting deep into the topic, it is vital to know and understand what is lipids.
Lipids is a important component in living things that are insoluble in water
and soluble in organic solvents like alcohol, ether and choloroform. There are
many types of lipids .To better understand various type of lipids, it is better
to view them in a mind map.
Not all of the lipids
works the same as some humans and mammal can easily break down the lipid and
synthesis it and some cannot be synthesised .Hence, the alternative is to
obtained it through our diet. Some of the characteristics of lipids is
non-polar and hydrophobic molecules .
Functions
of lipid
Why
does we need lipids or fats in our diet ? There are vast range of roles that lipids
hold. For example, lipids function as a primary source of energy. Although the
fact that excessive intake of fats is dangerous to our health ,we cannot deny
that it can act as our backup plan as when there is not enough glucose in our
body. Besides, the fat content in human body in fact can help human a lot when
there is not enough food and causes starvation to human as it allows humans to
survive up to 2 to 3 months. Secondly, lipids can protect our internal organ. Without
lipids, various organs will be in high risk of injury as there is no fat pads
that could protect them and give them structure. Thirdly, lipids can insulate
our body when the temperature drop to avoid any shock tour body systems. This
could be explain as the fats under the skin will metabolize to raise the body
temperature . It is also the precursor of hormone such as progestagens,
glycorticoids, mineralocorticoids, androgens and estrogens.
Type
of fatty acids
There are two types of
fatty acids which are saturated and unsaturated fats. The fatty acid is said to
be saturated if the bond between the neighbouring carbon in the hydrocarbon
chain is single. This makes that unsaturated fats is when the hydrocarbon has a
double bond. However as for unsaturated fats ,it is divided into two which are
monounsaturated and polyunsaturated. Monounsaturated fats is when there is only
one double bond while polyunsaturated fats is when there are more than one double
bonds. The biggest difference between saturated and unsaturated fats is they
give different effect to our body. As for saturated fats, it is unhealthy for our
body as compared to unsaturated fats .If the intake of saturated fats like meat
and dairy products is high, the possibility of getting coronary heart diseases
is very high. Hence, it is better for us to reduce the intake saturated fats to
keep our health in top condition.
Terpenes
Terpenes can also be
known as terpenoids and this are actually the biosynthethic building blocks of
every living creatures. This can be found in many plants and even some insects
creature. Terpenes have various biological benefits such as visual pigments, chloroplast
pigments, vitamin and precursors , color and odor associated with plants. Other
than that, terpenes also have some medical benefits as it can treat pain by
reducing inflammation,depression and anxiety.
Sphingolipids
Sphingolipids is a major
membrane component that can be found in brain cells and nerve cells..It can be
divided into several types which are sphingomyelins, cerebrosides and
gangliosides. Sphingomyelins is the only sphingolipid that are phospholipid and
make up of 25% of lipids in myelin sheath .Excessive build up of sphingomyelin in
liver, spleen, brain and bone marrow can cause Niemann-Pick disease which can
cause fatal to the effected child in just several years.
Cholesterol
Cholesterol is crucial
in the building the structure of cell membranes as it can maintain the fluidity
of the phospholipid over a wide range of physiological temperatures. Other than
that, it is also the precursor of hormones and vitamin D. Cholesterol synthesis
steroid hormones like oestrogen, testosterone and adrenal hormones. It also
acts as cell transporter and signalling molecules .For example, it helps in the
formation of lipid rafts in the plasma membrane.
Passive vs Active transport
Based on the class,
I am able to recall back on what I have learnt back in foundation regarding
this topic as it is quite same. Passive transport is a movement of ions from a
high concentration to a low concentration without the use of energy.It is
divided into three which are simple diffusion, facilitated diffusion and
osmosis. As for active transport, it is the movement of ion from low
concentration to a high concentration and it needs energy for this cellular
process. It is divided into primary and secondary active transport. Primary
active transport derived directly from the breakdown of ATP while for secondary
active transport is derived from energy that has been stored in the form of
ionic concentration differences between 2 sides of a membrane.
Signal
transduction
Last but not least, I
also had learnt about signal transduction which also can be known as cell
signalling in the class. In a simple way, this process involve the transmission
of signal from an cell’s exterior to its interior. The receptor will change its
shape upon the signal binding then conveying another signal inside the cell. These
process can take from seconds to minute even to hours or days to complete.
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