Question

complete the table below.

Type of fatty acidNumber of double bonds

Saturated

Monounsaturated

Polyunsaturated

  

List three food sources each for saturated, monounsaturated and polyunsaturated fats.

Saturated fat:

1. .

2. .

3. .

Monounsaturated fat:

1. .

2. .

3. .

Saturated fat:

1. .

2. .

3. .

What is the main type of phospholipid in food? ______________________________________

What is its function in the food industry? ___________________________________________

Phospholipids are important components of _____________________________ in the body.

Where does the body receive most of its lecithin from? _______________________________

What type of sterol is found in animal foods? ______________________________________

What is a beneficial function of plant sterols? ______________________________________

List three compounds that our bodies make from cholesterol:

1. .

2. .

3. .

The gallbladder secretes _________________ to emulsify the lipids and make them available for digestion.

The two enzymes secreted into the small intestine to digest lipids are:

1. .

2. .

These enzymes break triglycerides down into:

1. .

2. .

3. .

list the three lipid particles that can be directly absorbed into the bloodstream:

1. .

2. .

3. .

Lipoprotein What does it transport?

What type of lipoprotein is associated with a high risk of heart disease? _______________________

What type of lipoprotein is associated with a lower risk of heart disease? ______________________

How much fat can be stored in adipose tissue? _________________________________________

Answer 1

Saturated fatty acids contain no double bonds or unsaturation in their fatty acid chain. Mono unsaturated fatty acids contain only one double bond in their fatty acid chain. Poly unsaturated fatty acids contains more than one double bond or unsaturation in their fatty acid chain.

Butter, palm oil and full cream dairy products contain saturated fatty acids. Nuts , avocado and sunflower oil contain mono unsaturated fatty acid. Soybean oil, walnuts and flax seeds contain polyunsaturated fatty acid.

The main type of phospholipid in food is lecithin. It is a mixture of phospholipids like phosphatadyl choline, phosphatadyl ethanolamine, phosphatadyl inositol, phosphatadic acid, phosphatadyl serine.

In food industry it is used as an emulsifying agent. It is generally obtained from soy.

Phospholipids are a important constituent of the cell membrane. It is constructed by phospholipids and forms a bilayer.

Lecithin is obtained from soybean oil, canola oil, cotton seed oil. The body also gets lecithin feom animal food sources also.

Cholesterol is the peimary sterol present in animals. It helps in maintaining the membrane fluidity.

Plant sterols are effective as they help in reducing high concentration of cholesterol from blood which may be due to hypercholesterolemia. Plants sterols reduce the low density lipoprotein whic reduces cardiac disease risk.

The body synthesizes vitamin-D, bile acids and various steroid hormones from cholesterol.

The gallbladder secrets bile acid during digestion of lipids which helps in emulsifying the lipid. Bile acids lower the surface tension and thus they aid in emulsification of fats. They also help in accelerate the actuon of pancreatic lipase. And they also form micelles with fatty acids making them water soluble for absorption.

Pancreatic lipase , phospholipase A2 and help in the breakdown of triglyceride in the small intestine.

This enzyme break triglyceride in to free fatty acid and glycerol. The free fatty acid is then further metabolise.

In plasma cholesterol and triglycerides form a macromolecular complex called lipoprotein. Lipoproteins help in the transport of cholesterol and triglycerides.

The low density lipoprotein or LDL is associated with cardiac disease and the High density lipoprotein or HDL reduces the risk of cardiac disease by lowering the LDL level by its scavenging actions. When apo-LDL is modified by lipid peroxidation it attracts macrophages which converts it to foam cells and this local elevation of lipid hydroperoxides leads to decrease in prostacyclin and thromboxane ratio which can lead to thrombosis and further proceeds towards atherosclerosis.