Chapter 5: The Lipids: Triglycerides, Phospholipids, and Sterols

Flashcards covering key concepts from Chapter 5: The Lipids, including triglycerides, phospholipids, sterols, digestion, absorption, transport, roles in the body, health effects, and dietary recommendations.

What are the three main types of compounds included in the lipid family?

Triglycerides, phospholipids, and sterols

What is the most abundant type of fat found in food and in the body?

Triglycerides

What is the structure of a triglyceride?

Glycerol + 3 fatty acids

What are the two essential fatty acids?

Linoleic acid (omega-6) and Linolenic acid (omega-3)

How is the 'omega number' of a fatty acid determined?

It represents the location of the closest double bond from the methyl end of the carbon chain.

Why do saturated fats tend to be solid at room temperature?

Saturated fatty acids tend to stack together neatly.

What process involves the addition of hydrogens to remove double bonds in fats, making them more solid and resistant to oxidation?

Hydrogenation

What is the key difference between cis and trans fatty acids?

Cis fatty acids have hydrogens on the same side of the double bond (bending into a U-like formation), while trans fatty acids have hydrogens on opposite sides (making them more linear).

What is the primary role of phospholipids in the body?

They are part of cell membranes and act as emulsifiers, keeping fats suspended in blood and body fluids.

In which food sources is lecithin, a well-known phospholipid, commonly found?

Eggs, liver, soybeans, wheat germ, and peanuts

Besides forming a structural component of cell walls, what are some other roles of sterols in the body?

They are precursors for bile acids, sex hormones (testosterone), adrenal hormones (cortisol), and Vitamin D.

What is the main goal of fat digestion?

To dismantle triglycerides into monoglycerides, fatty acids, and glycerol.

Which hormone signals the gallbladder to release bile during lipid digestion in the small intestine?

Cholecystokinin (CCK)

What are micelles and what is their role in lipid absorption?

Micelles are tiny spherical complexes of emulsified fat that transport the products of lipid digestion (monoglycerides, fatty acids, cholesterol) to the intestinal cells for absorption.

What are chylomicrons and how do they transport large lipids?

Chylomicrons are lipoproteins formed in intestinal cells from triglycerides, cholesterol, and phospholipids, which bypass the liver initially and travel through the lymph before entering the bloodstream.

Which lipoprotein is known as 'bad cholesterol' and primarily transports cholesterol to the cells?

LDL (Low-Density Lipoprotein)

Which lipoprotein is known as 'good cholesterol' and picks up cholesterol from cells and tissues to bring it back to the liver for excretion?

HDL (High-Density Lipoprotein)

What is adipose tissue and what hormone does it secrete that can increase inflammation and insulin resistance in obesity?

Adipose tissue stores body fat and secretes hormones called adipokines, including resistin.

What are eicosanoids and what type of health benefits do those made from omega-3 fatty acids typically provide?

Eicosanoids are 'hormonelike' compounds made from omega-3 and omega-6 fatty acids; those from omega-3 typically lower blood pressure and control inflammation.

How do saturated fats and trans fats affect blood cholesterol levels?

Saturated fats increase LDL cholesterol, while trans fats increase LDL and lower HDL cholesterol.

According to dietary recommendations, what is the recommended percentage of daily energy intake from fat and from saturated fat?

20-35% of daily energy from fat, with less than 10% from saturated fat.