Chapter 5 Objectives

5.5 Explain the relationships among saturated fat, trans fat, and cholesterol and chronic diseases, noting recommendations

20 to 35% intake from fat, less than 10% from saturated fats, as little trans fats as possible, less than 300 milligrams of cholesterol.

Describe the link between hydrogenation and trans fats.

cis: Has its hydrogen molecules on the same side of the double bond. Trans: Has its hydrogen atoms on the opposite sides of the double bond

Differentiate between cis and trans fats.

cis: Has its hydrogen molecules on the same side of the double bond. Trans: Has its hydrogen atoms on the opposite sides of the double bond

Explain the connection between a high LDL concentration and cardiovascular disease

elevated LDL cholesterol is a major risk for CVD. LDL accumulates in the arteries, blood flow becomes restricted and blood pressure rises.

Describe the structure, purpose and function of the following lipid transport molecules: micelles, chylomicrons, VLDL'S, HDL'S, LDL'S

i. Chylomicrons: Largest and least dense (Most fat; least protein). Transport diet derived fats. Absorbed glycerol and fatty acids reassembled in intestinal cells.Packaged with cholesterol and phospholipids. Travels through lacteals to bloodstream ii. VLDL's: Very-low density lipoproteins. High lipids; low proteins. Remove triglycerides as they travel. VLDL's become LDL's iii. LDL's: Low-density lipoproteins. High cholesterol, low triglycerides. Delivers triglycerides, cholesterol and phospholipids to cells. iv. HDL's: High-density lipoproteins. High protein low cholesterol. Removes cholesterol from cells and returns it to the liver. v. Micelles: ?

Give examples of foods containing omega-6 and omega-3 fatty acids

omega 3 - vegetable oils, such as soybean, rapeseed (canola), and flaxseed, and in walnuts. Omega 6 - include poultry, meat, eggs, nuts, seeds, oils, cereals, wholegrain breads, and evening primrose oil

Explain the health effects of consuming omega-6 and omega-3 fatty scids

...

Give examples of hydrogenated fats and foods high in trans fats.

...

5.1 Recognize the chemistry of fatty acids and triglycerides and differences between saturated and unsaturated fats.

...

5.2 Describe the chemistry, food sources, and roles of phospholipids and sterols

...

5.3 Summarize fat digestion, absorption, and transport

...

5.4 outline the major roles of fats in the body, including a discussion of essential fatty acids and the omega fatty acids

...

5.6 Explain the relationship between monounsaturated fats and polyunsaturated fats and health, noting recommendations

...

Describe the circumstances under which each would be active

...

Describe the effect each has on triglyceride synthesis/breakdown.

...

Give examples of the role of fats in the body besides providing energy

Layer of fat beneath the skin insulates the body from temperature extremes. Fat pads also serve as natural shock absorbers, providing a cushion for the bones and vital organs. Fat provides the structural material for cell membranes and participates in cell signaling pathways.

Recognize that linoleic acid is an omega-6 fatty acid and linolenic acid is an omega-3 fatty acid

Linoleic acid - omega 6 fatty acid. used to make other member of the family like arachidonic acid, 20 carbon polyunsaturated fatty acid. Has to be obtained through diet Linolenic acid - must be obtained through diet. Can create small amounts of 20- and 22- carbon members of the o3family

Define conditional essential nutrient

a nutrient that is normally nonessential, but must be supplied by the diet in special circumstances when the need for it exceeds the bodies ability to produce it

Describe and identify the chemical structure of fatty acids, glycerol and triglycerides.

a. Fatty Acid: Chain of Carbon and hydrogen atoms with an acid group (COOH) at one end and a methyl group (CH3) at the other. b. Glycerol: An alcohol composed of a three-carbon chain c. Triglycerides: Composed of a molecule of glycerol with three fatty acids attached.

Explain how the following get into the blood for transport to cells throughout the body: glycerol, monoglycerides, medium chain fatty, long chain fatty acids, short chain fatty acids, triglycerides, cholesterol, phospholipids

a. Glycerol: Can fuse easily into the intestinal cells. They are absorbed directly into the bloodstream. b. Short-chain fatty acids: Can fuse easily into the intestinal cells. They are absorbed directly into the bloodstream c. Medium-chain fatty acids: Can fuse easily into the intestinal cells. They are absorbed directly into the bloodstream. d. Monoglycerides: Emulsified by bile forming spherical complexes known as micelles. They diffuse into the intestinal cells where they are reassembled into new triglycerides. Within the intestinal cells the new triglycerides and other lipids ( Cholesterol and phospholipids) are packed with protein into transport vehicles known as chylomicrons. The cells then release the chylomicrons into the lymph system. They go through the lymph until they reach a point of entry into the bloodstream at the thoracic duct near the heart. Blood carries these to lipids to the rest of the body for immediate use of storage. e. Long-chain fatty acids: Emulsified by bile forming spherical complexes known as micelles. They diffuse into the intestinal cells where they are reassembled into new triglycerides. Within the intestinal cells the new triglycerides and other lipids ( Cholesterol and phospholipids) are packed with protein into transport vehicles known as chylomicrons. The cells then release the chylomicrons into the lymph system. They go through the lymph until they reach a point of entry into the bloodstream at the thoracic duct near the heart. Blood carries these to lipids to the rest of the body for immediate use of storage.

Explain what is generally included in a blood lipid profile

Blood lipid profile reveals the concentrations of various lipids in the blood, notably triglycerides and cholesterol, and their lipoprotein carriers (VLDL, LDL, and HDL). It alerts people to disease risks and perhaps a change in physical activity and eating habits.

List the key elements found in lipids

Carbon, Hydrogen, Oxygen

Describe the chemical structure and properties of a phospholipid

Compound similar to triglyceride, but having the third site which is occupied by a phosphate group and a molecule of choline in place of one of the fatty acids.

Describe the chemical structure and properties of a sterol

Compounds containing a four-ring carbon structure with any of a variety of side chains attached. Interfere and lowers blood cholesterol levels.

State the DRI for trans fats

DRI: < 3 g/day

Explain how the structure of the fatty acid contributes to its state at room temperature.

Generally, the shorter the carbon chain, the softer the fat is at room temperature.

Explain hydrogenation and its purpose

Hydrogenation produce trans-fatty acids by adding hydrogen molecules to the structure.

Outline how these lipase's aid in getting fats into and out of the body cells.

Lipoprotein Lipase - Hormone-sensitive lipase: Energy hungry cells anywhere in the body can then capture these compounds and take them through a series of chemical reactions to yield energy.

Explain the role of lipoprotein lipase and hormone- sensitive lipase in fat storage and release.

Lipoprotein lipase - hydrolyzes triglycerides from these lipoproteins, releasing fatty acids, diglycerides, and monoglycerides into adipose cells. Enzymes inside the adipose cells reassemble these fatty acids, diglycerides, and monoglycerides into triglycerides again for storage. Hormone-sensitive lipase: breaks down stored triglycerides and releasing the glycerol and fatty acids directly into the blood.

Briefly explain the biological role of sterols

Many important body compounds are sterols. Those being cell membranes, bile acids, sex hormones, vitamin D. Cholesterol made in the body is known as endogenous and formed outside of the body is known as exogenous

Differentiate between saturated and unsaturated fatty acids, including the following the following info: structure, health, firmness, examples, melting point.

Saturated ii. Fully loaded with all its hydrogen atoms and contains only single bonds between its carbon atoms. iii. Solid at room tempature iv. Linear Structure: Allows for stacking v. Less Healthy: contributes to atherosclerosis vi. Examples: Butter, Coconut Oil Unsaturated viii. Missing hydrogen and contains a double bond. ix. Liquid at room tempature x. Bent Structure: Prevents stacking xi. Healthier xii. Examples: Olive Oil, Vegetable Oil xiii. Can become saturated through hydrogenation

Describe the suggested ratio of omega-6 fatty acids to omega-3 fatty acids in the diet

Suggested ratios range from 4:1 to 10:1

State the common phospholipid

The most common phospholipid is Lecithin

State the most common sterol

The most common sterol is cholesterol.

Briefly explain the biological and industrial roles of phospholipids.

They are used in foods as emulsifiers. Biologically they are constituents of cell membranes. Because they are soluble in both water and fat, they can help fat-soluble substances, including vitamins and hormones, to pass easily in and out of cells. They also act as emulsifiers in the body, helping to keep fats suspended in the blood and body fluids.

Explain the health concern posed by trans fats

They behave more like saturated fats, increasing blood cholesterol and the risk of heart disease.

Explain what happens to triglycerides as they pass through each segment of the digestive tract, including the role played by each of the following: lingual lipase, gastric lipase, pancreatic lipase, intestinal lipase, fiber

a. Lingual lipase: an enzyme released in the mouth that plays and active role in fat digestion in infants, but a relatively minor role in adults. In infants, this enzyme efficiently digests the short and medium chain fatty acids found in milk b. Gastric Lipase: Occurs in the stomach. The stomach mixes fat with water and acid. This churning grinds the solid pieces to finer particles and disperses the fat into small droplets. It is then hit by gastric lipase enzyme which performs best in the acidic stomach environment. Still little fat digestion takes [lace in the stomach. c. Bile: occurs in the small intestine. Cholecystokinin triggers the gallbladder to release stores of bile. Bile acts as an emulsifier, drawing fat molecules into the surrounding watery fluids. d. Pancreatic Lipase: occurs in small intestine. It flows in from the pancreas. These enzymes remove each of a triglyceride's outer fatty acids one at a time, leaving a monoglycerides. Fats fully digested with help of intestinal lipase e. Intestinal lipase: Occurs in small intestine. Less than pancreatic enzymes, mostly there to help. f. Fiber: Some fat and cholesterol, trapped in fiber, exit in feces.