This Lecture Deals with Activation, Transport and General Mechanism of Fatty acid Oxidation

1. Biochemistry VII Lecture-2
Intermediary Metabolism
OXIDATION OF FATTY ACIDS

2. Lipid Metabolism
Blood lipids and dietary lipids
Common blood lipids: are cholesterol and triglycerides
Sources of dietary FATS:
Fats of animal origin :
Fats of plants origin:
Other sources

3. Lipid Metabolism
Oxidation of Fatty acids
•Introduction to Beta oxidation
•Carnitine shuttle
•The Pathway of Beta-Oxidation: steps Invovled
•β-Oxidation of even-chain Saturated Fatty Acids
•Oxidation of odd-chain and unsaturated fatty acids

13. carnitine cycle enables the transport of long-chain fatty acids into the mitochondria to enter the -
oxidation cycle.
Carnitine chemical name-Trimethyl ammonium butrate involved in metabolism in most mammals,
plants, and some bacteria.
It is synthesized from Lys and Met in liver and kidney

20. Blood lipids and dietary lipids
• Blood lipids are lipids in the blood either in free or bound form
• Blood lipids are influenced by many factors including
dietary factors (meal composition and calorie intake),
lifestyle conditions (exercise, alcohol consumption, and smoking),
physiological factors (gender and age),
health conditions (diabetes and obesity), and
genetic background.
• Blood lipids are mostly transported in a protein capsule, and the density of the lipids and type of
protein determines the fate of the particle and its influence on metabolism.
• The concentration of blood lipids depends on intake and excretion from the intestine, and uptake
and secretion from cells.
• Hyperlipidemia is the presence of elevated or abnormal levels of lipids and/or lipoproteins in the
blood, and is a major risk factor for cardiovascular disease.

21. Blood lipids

22. Blood lipids-Common blood lipids: are Cholesterol
and Triglycerides
CHOLESTEROL
Total Blood cholesterol Level should be:
• <200 mg/dl normal blood cholesterol,
• 200–239 mg/dl borderline-high,
• >240 mg/dl high cholesterol.

23. Blood lipids- Cholesterol
• Cholesterol is transported in the bloodstream by Lipoproteins that are water-
soluble and carry cholesterol and TG internally.
• The liver converts unburned food metabolites into (VLDL) and secretes them into
plasma where they are converted to intermediate density lipoproteins(IDL), which
thereafter are converted to (LDL) particles and non-esterified fatty acids, ".
• Intestine excretion : After being transported to the liver by HDL, cholesterol is
delivered to the intestines via bile production..
• Cell uptake: Cholesterol circulates in the blood in VLDL and these are taken into
the cell, and then hydrolysed in lysosomes.
• Cell secretion: In response to low blood cholesterol, different cells of the body,
mainly in the liver and intestines, start to synthesize cholesterol from acetyl coA

24. Blood lipids- Triglyceride
• Triglycerides, or blood fats, are the fats that circulate through the bloodstream
along with cholesterol. Your body gets triglycerides from food (especially meats
and plant oils) and also makes triglycerides on its own. High triglyceride levels
increase your risk of heart and blood vessel disease.
• For triglycerides, a healthy reading is 150 mg/dl or less..
• Cell uptake: After a meal, when the blood concentration of fatty acids rises, there
is an increase in uptake of fatty acids in different cells of the body, mainly Liver
cells, adipocytes and Muscle cells.
• Cell secretion: After a meal, some of the fatty acids taken up by the liver is
converted into (VLDL) and again secreted into the blood.

25. Dietary Lipids
The major dietary lipids for humans and other animals are
animal and plant triglycerides,
sterols, and
membrane phospholipids.
Sources of dietary FATS:
• Fats of animal origin : Ghee, butter, milk, cheese, eggs and fat of meat and fish
• Fats of plants origin: Groundnut oil, Coconut oil, Palm oil, Mustard oil, Canola
oil, Sesame oil, Corn oil
• Other Sources: Cereals, Pulses, Oil seeds (Sunflower, Safflower, Soyabean,
Cottonseeds), rice bran and Leafy green vegetables

26. Dietary Lipids
• Products of Fats Metabolism are
• Fatty Acids;
• Triglycerides;
• Phospholipids;
• Sterols;
• Lipoproteins

27. Dietary Lipids
Fatty Acids:
Saturated Fatty Acids
Unsaturated Fatty Acids – Monounsaturated Fatty Acids - Polyunsaturated
Fatty Acids
Saturated fatty acids
• Sources : Animal foods such as meat, poultry and full-fat dairy products
Tropical oils such as palm and coconut; RDA: Less than 10% of total energy
intake per day.

28. Dietary Lipids
Unsaturated fatty acids are found in foods from both plant and animal sources.
• Monounsaturated fatty acids: Sources: vegetable oils such as olive, canola, and
peanut.
Monounsaturated Fatty acids (MUFAs) are of two type:
• 1) Cis- unsaturated fatty acids 2) Trans- unsaturated fatty acids
• Produced during partial hydrogenation of vegetable oils.
• Also developed in vegetable oils during frying and heating.
Essential Fatty Acids: Sources of linoleic acid: Leafy vegetables, nuts, vegetable
oils (seasame, corn oil, sunflower, soybean), poultry fat
• Sources of linolenic acid (Omega 3 fatty acids): Nuts, seeds (soybean, walnuts,
flaxseed) and oils (soybean, canola)

29. Dietary Lipids
Triglycerides & Phospholipids:
Food Sources: Most abundant in egg yolks, liver, soybeans, and peanuts
Sterols:
Food Sources: Highest in organ meats like beef kidney, beef liver, and beef brain,
egg yolks, and breast milk