Lipids

Lipids

Lipids are fatty compounds that perform a variety of functions in your body. They're part of your cell membranes and help control what goes in and out of your cells.

structure of lipids

CH3(CH2)nCOOH

Function

• lipids are important in the body for energy storage
• lipids are also important for the cell membrane 
• contains twice the amount of energy found in carbohydrates

 Additional information

• in a body that weighs 150 pounds, 22 of those pounds will be lipids 
• this is often why humans can live several days without food
• can also go several days without water 
• lipids are a chemically diverse group of compounds 

phospholipids structure

2 fatty acids = non polar = hydrophobic

one phosphate head = polar = hydrophobic

phospholipids make up the cell membrane. they are arranged in 2 layers which is called "phospholipids bilayer"

The types of lipids:

Steroids:

steroid is a lipid with 4 fused carbon rings.

for examples:

cholesterol

hormones

vitamins(B,D,A)

waxes:

are solid at room temperature and insoluble in water.

its a protective layer which protects plants and animals.

for example cuticle, leaf, earwax.

cholesterol: 

belongs to the steroid group of lipids.

the cholesterol in your blood comes from 2 sources: the foods you consume like dairy and meat.

your liver makes the cholesterol your body needs.

Triglycerides:

 

they are the main form of lipids in plants and animals.

more than 95 percent of the fats we eat are in triglyceride form.

extra sugar in our body turns into triglycerides and are stored in fat cells throughout the body.  

The fatty acid chain of lipids can come in two forms; saturated and unsaturated. Saturated fatty acid chains contain only single bonds between the carbons. Unsaturated fatty acids contain a double bond between two carbons in the chain. Unsaturated fatty acids contain either cis or trans double bonds. 

Polyunsaturated fats are considered healthy fats, as they may reduce your risk of heart disease

Why do we eat lipids?

They are important in the diet as energy sources and as sources of essential fatty acids and fat-soluble vitamins, which tend to associate with fats.

0.5-1g/kg of fat should be consumed per day to avoid essential fatty acid deficiency.

why we shouldn't eat fatty acids

Eating too much saturated fats in your diet can raise "bad" LDL cholesterol in your blood, which can increase the risk of heart disease and stroke. "Good" HDL cholesterol has a positive effect by taking cholesterol from parts of the body where there's too much of it to the liver, where it's disposed of

Lab

We did an experiment in the lab about which substances had the most amount of lipids, the substances were, milk, soda, water, and oil. we added the ethanol into each tube to see which one had the most lipids. the substances would form a layer on top, after some time we noticed that oil had the most amount of lipids.