The Lipids: Triglycerides, Phospholipids, and Sterols

Flashcards about Lipids: Triglycerides, Phospholipids, and Sterols

What are Lipids?

Family of compounds composed of Carbon, Hydrogen, and Oxygen. Includes triglycerides, phospholipids, and sterols.

What are Triglycerides?

Most abundant type of fat in food and in the body, composed of glycerol and three fatty acids.

What are Fatty Acids?

4-24 carbons (18 is most common), can be saturated or unsaturated (mono- or poly-)

What are essential fatty acids?

Omega-3 (linolenic acid) and omega-6 fatty acids (linoleic acid)

Compare Saturated and Unsaturated Fatty Acids

Saturated fatty acids tend to stack together, solid at room temperature. Unsaturated fatty acids bend at the double bond and are liquid at room temperature.

What is hydrogenation?

Addition of hydrogens to poly- or monounsaturated fats to reduce the number of double bonds

What are Phospholipids?

Glycerol + 2 fatty acids + phosphate group and choline

What are the roles of Phospholipids?

Part of cell membranes, emulsifiers in food and body, help fat-soluble vitamins and hormones pass into cells

What are the Food sources of Sterols?

Animal sources - Cholesterol. Plant sources - Plant Sterols

What are the roles of Sterols?

Bile acids, sex hormones, adrenal hormones, vitamin D, structural component of cell membranes

What is the Goal of Fat Digestion?

Dismantle triglycerides into monoglycerides, fatty acids, and glycerol

What is the Challenge of Fat Digestion?

Fats are hydrophobic and digestive enzymes are hydrophilic

What is the role of Small intestine in Fat Digestion?

CCK signals gallbladder to release bile from the common bile duct. Pancreatic lipase flows in from the pancreatic duct.

What are Micelles?

Spherical structures of emulsified fat (fatty acids, monoglycerides and cholesterol) with bile

What is the main function of Chylomicron?

Deliver dietary fat from the small intestine to the cells.

What is the main function of VLDL-cholesterol?

Transport lipid from the liver to the cells.

What is the main function of LDL-cholesterol?

Transport cholesterol (dietary and cholesterol made by the body) to the cells.

What is the main function of HDL-cholesterol?

Cholesterol "scavenger” that picks-up cholesterol from cells and tissue. HDL brings cholesterol back to the liver so that it can eventually be excreted.

How body stores fat?

Adipose tissue stores body fat and secretes hormones made of proteins (adipokines)

What are benefits of Omega-6 Fatty Acids?

Regulates brain functioning, regulates growth and development, stimulates hair and skin growth, regulates metabolism, maintains healthy bones and reproductive system, increases inflammation

What are benefits of Omega-3 Fatty Acids?

Control blood clotting, builds cellular membranes in the brain, enhances brain and joint function, may promote fat loss and muscle building benefits in athletes, reduces risk of cancer, heart disease and diabetes, reduces inflammation

What are Eicosanoids

Made from omega-3 and omega-6 fatty acids. Include prostaglandin, thromboxane, leukotriene

What blood lipid profile reveals cardiovascular disease (CVD) risks?

Elevated LDL, low HDL, elevated triglycerides are risk factors

What are the recommended intakes of Saturated Fat and Trans Fat and Essential Fatty Acids?

Limit saturated and trans fat. Consume enough fats for good health.

How much energy does 1 gram of fat provide?

9 kcal

In which part of the GI tract does most fat digestion occur?

the small intestine

whats the fat-digesting enzyme secreted from the mouth

lingual lipase

Which of the following is an essential fatty acid? Arachidonic acid,Stearic,Linoleic, Palmitate

Linoleic acid

Which statement accurately describes lecithin?

a) It is used as an emulsifier by the food industry

b) It is similar to triglycerides, but contains four fatty acids

c) It is soluble in fat, but not in water

d) It is the best-known sterol

a) It is used as an emulsifier by the food industry.

what does the stomach do in lipid digestion

stomach contractions mix and break down fats, while gastric lipase continues the digestion process.

what does the large intestine do in lipid digestion

The large intestine absorbs any remaining nutrients and water from digested fats and helps form waste for excretion.