In biochemistry, lipids are molecular organic compounds, composed largely of carbon and hydrogen, that are essential for cell growth. Lipids are non-soluble in water and combine with carbohydrates and proteins to form the majority of all plant and animal cells. They are more commonly synonymous with the word "fats" when speaking in terms of personal health. Although all fats are lipids, not all lipids are fats.

1. Lipids
By “DrRobisAwesome”

2. Activity Objective
• Activity Objective. Students will make visual
observations of fat and then extract and
examine the invisible fat from chocolate,
potato chips, and sunflower seeds.

3. Activity Objective

4. Plant lecithins of vegetable oils
• Plant lecithins are a by-product in the refining
of vegetable oils. During the usual batch
degumming process the crude oil is heated to
about 70 °C, mixed with 2% water and
subjected to thorough stirring for about half
an hour to an hour. This addition of water to
the oil hydrates the polar lipids in the oil,
making them insoluble. The resulting lecithin
sludge is then separated by centrifugation.

5. The crude plant lecithin
• This sludge is made up of water, phospholipids
and glycolipids, some triglycerides,
carbohydrates, traces of sterols, free fatty
acids and carotenoids. The crude plant lecithin
is obtained by careful drying.

6. Can also use acetone
Lipid-solvent extraction

7. Sunflower seeds

8. Also steriods- and signaling
• The steroids, all derived from the same fused
four-ring core structure, have different
biological roles as hormones and signaling
molecules (the estrogen family,
• the androgens such
as testosterone and androsterone, the
• progestogens and the vitamin D

10. naturally occurring molecules
• Lipids constitute a broad group of naturally
occurring molecules that include fats, waxes,
• sterols, fat-soluble vitamins (such as vitamins
A, D, E, and K),
• monoglycerides, diglycerides, triglycerides,
• phospholipids, and others.

11. • The main biological functions of lipids include
energy storage, as structural components
of cell membranes, and as important signaling
molecules.

12. C, H and O
• They are compounds of C, H and O.
Occasionally also N and P.

13. Popular lipids

14. CLASSIFICATION
• FATTY ACIDS
• In chemistry, especially biochemistry, a fatty
acid is a carboxylic acid with a
long aliphatic tail (chain), which is
either saturated or unsaturated. Most
naturally occurring fatty acids have a chain of
an even number of carbon atoms, from 4 to
28. Fatty

15. • Fatty acids are usually derived
from triglycerides or phospholipids. When
they are not attached to other molecules, they
are known as “free” fatty acids. Fatty acids are
important sources of fuel because, when
metabolized, they yield large quantities of ATP.
Many cell types can use either glucose or fatty
acids for this purpose.

16. • In particular, heart and skeletal muscle prefer
fatty acids. The brain cannot use fatty acids as
a source of fuel; it relies on glucose or ketone
bodies.

17. TRIGLYCERIDES
• TRIGLYCERIDES
• A triglyceride (TG, triacylglycerol, TAG,
or triacylglyceride) is an ester derived
from glycerol and three fatty acids.

18. TRIGLYCERIDES

19. esterification of triglycerides with
ethanol

20. ACID OR BASE CATALYZED

21. vegetable oil
• Triglycerides are the main constituents
of vegetable oil (typically more unsaturated
(with double links inside the structure of the
fatty acids) and animal fats (typically more
saturated (without double links).

22. Steric acid and oleic acid

23. storing unused calories
• In humans, triglycerides are a mechanism for
storing unused calories, and their high
concentration in blood correlates with the
consumption of starchy and other high
carbohydrate foods. Triglycerides are a major
component of human skin oils.

24. human skin oils

25. PHOSPHOLIPIDS
• PHOSPHOLIPIDS
• Phospholipids are a class of lipids that are a
major component of all cell membranes as
they can form lipid bilayers. The structure of
the phospholipid molecule generally consists
of hydrophobic tails and a hydrophilic head. It
is usually found with cholesterol molecules
which are found in-between the spaces of the
phospholipid.

26. PHOSPHOLIPIDS
• PHOSPHOLIPIDS cholesterol molecules
• It is usually found with cholesterol molecules
which are found in-between the spaces of the
phospholipid.

27. PHOSPHOLIPIDS and
cholesterol molecules

28. STEROL LIPIDS
• STEROL LIPIDS
• Sterol lipids, such as cholesterol and its
derivatives, are an important component of
membrane lipids, along with the
phospholipids and sphingomyelins.

29. phospholipids and sphingomyelins

30. Cholesterol
• Cholesterol is the most abundant steroid, and
it is the precursor for all the other important
steroids of mammalian metabolism. It is
amphipathic.

31. Steroid backbone

32. The steroids
• The steroids, all derived from the same fused
four-ring core structure, have different
biological roles as hormones and signaling
molecules (the estrogen family, the androgens
such
as testosterone and androsterone, the progest
ogens and the vitamin D

33. Steroid backbone

34. nervous system
• - Lipids make up 70% of the dry weight of the
nervous system. They are crucial to healthy
functioning of nerve cells.
• - Lipids are important to basic biological
functions such as energy storage, membrane
structure, myelin, and signaling molecules.

35. What is a sphingolipid?
• 1. Sphingolipids – accumulation of abnormal
sphingolipids is observed in HSAN1 (see here
for more on our HSAN1 research) patients due
to mutations to in SPTLC1, a gene responsible
for synthesis.
• Serine palmitoyltransferase, long chain base
subunit 1, also known as SPTLC1, is a protein
which in humans is encoded by the SPTLC1
gene.[1][2]

36. What is a sphingolipid?
• - A class of lipids that are highly enriched in
neural tissue.
• - Sphingolipids are important in cell signaling,
lipid rafts, myelin and cell membranes.

37. typical structure of a sphingolipid

38. typical structure of a sphingolipid
• Below is the typical structure of a
sphingolipid. Changing the R group will result
in different sphingolipids.

39. the bile acids and their conjugates

40. Help digest

41. oxidized derivatives of cholesterol
• Other examples of sterols are the bile
acids and their conjugates, which in mammals
are oxidized derivatives of cholesterol and are
synthesized in the liver.

42. Better view

43. plant equivalents
• The plant equivalents are the phytosterols,
such as β-sitosterol, stigmasterol,
and brassicasterol; the latter compound is also
used as a biomarker for algal growth. The
predominant sterol in fungal cell membranes
is ergosterol.

44. Linum usitatissimum

45. Membrane lipids

46. Membrane lipids