LIPID METABOLISM

Bag.Biokimia FK USU

Function of lipida

• Produce energy (FA and keton body)

• Forms Phospholipid and Glykolipid (cell)(cell)

• Membrane integrity

• Bile acid.

• Hormon Steroid

• Vitamin D

• Prostaglandins (PG, TX and LT)

Lipid classes

• Fatty acids

• Tryacylglycerols

• Phosholipids (phosphoglycerides and • Phosholipids (phosphoglycerides and sphingomyelin )

• Glikolipids

• Isoprenoids

Structure Fatty Acid

• Fatty acid ( C 14 – 24 )

- Saturated

- Unsaturated - Unsaturated O

• H3C - (CH2)n - CH2 - CH2 - C

ω β α OH

Saturated Fatty Acid

• Myristic acid (C14)

• Palmitic acid (C16)

• Stearic acid (C18) • Stearic acid (C18)

• Arachidic acid (C20)

• Lignoceric acid (C24)

• Cerotic acid (C26)

Unsaturated Fatty acid

• Palmitoleic acid (C16 double bond cis ∆9)

• Oleic acid (C18 double bond cis ∆ 9)• Oleic acid (C18 double bond cis ∆ 9)

• Linoleic acid (C18 double bonds cis ∆ 9,12)

• α - Linolenic acid (C18 double bonds cis ∆ 9,12,15

• Arachidnic acid (C2o double bonds cis ∆5,8,11,14

Digestion and absorption of tryacylglicerols

Regulation

Regulation

• When energy low �the the body’s fat stores mobilized�lipolysis

• Lypolisis :fasting, vigorous exercise • Lypolisis :fasting, vigorous exercise and response to stress.

• When energy high �Lipogenesis

• Hormone binding to the receptor ��cAMP �activates hormone sensitive triacylglycerol lipase.

�Both products of lypolisis �released into the blood.

�Fatty acids are combined with albumin in the plasm �to tissues Fatty acids are combined with albumin in the plasm �to tissues �are oxidized to generate enegy.

�Brain and red blood cells can not use fatty acids as fuel.

�Fatty acids are degraded to form acetyl coA

Lipid transport• Plasma lipoprotein

• Are synthesized in both intestine and liver.

• The protein components of • The protein components of lipoproteins are called apolipoprotein or apoprotein.(A,B,C,E)

• Classification: Chylomicron,VLDL,IDL, LDL, HDL .

• Electrophoretic : α,β and pre β -

lipoproteins.

Lipid TransportLipid TransportLipid TransportLipid Transport

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