Exam 2: HUN 2201 Material

What is the structure of a fatty acid? (ch.5)

An organic molecule made up of a chain of carbons linked to hydrogen atoms with an acid group on one end

What is the effect of chain length on a fatty acid? (ch.5)

Chain length determines the physical form of a fat at room temperature.

What is the physical form of a short-chain fatty acid at room temperature? (ch.5)

(4-7 carbons) Liquid

What is the physical form of a medium-chain length fatty acid at room temperature? (ch.5)

(8-12 carbons) Liquid but solidifies in the refrigerator

What is the physical form of a long-chain fatty acid at room temperature? (ch.5)

(greater than 12 carbons) Solid

What is a saturated fatty acid? (ch.5)

A fatty acid that contains no carbon-carbon double bonds.

What is an unsaturated fatty acid? (ch.5)

A fatty acid that contains at least one carbon-carbon double bond.

What is a triglyceride? (ch.5)

A major form of lipid that consists of three fatty acids attached to a glycerol molecule.

What are the three types of fatty acids found in food? (ch.5)

Triglycerides, Phospholipids, and Sterols

What is a phosphoglyceride? (ch.5)

A class of phospholipid consisting of a glycerol molecule, 2 fatty acids, and a phosphate group.

Cholesterol (ch.5)

A lipid that consists of multiple chemical rings and is made only by animal rings.

Omega-3 fatty acid (ch.5)

A fatty acid containing a carbon-carbon double bond between the third and fourth carbons from the omega end. (example: alpha-linolenic acid)

Omega-6 fatty acid (ch.5)

A fatty acid containing a carbon-carbon double bond between the sixth and seventh carbons from the omega end (example: linolenic acid)

What is the role of phospholipids in the body? (ch.5)

Act as emulsifiers by mixing with water and fat breaking large fat globules into smaller ones, as phosphoglycerides form a lipid bilayer, as lecithin optimizes the function of a cell membrane

What is the role of sterols in the body? (ch.5)

As cholesterol it is needed to synthesize vitamin D, cholic acid, and hormones

Summarize the digestion of lipids in the human body. (ch.5)

1) Lipid digestion begins in the stomach via lipases produced by the stomach and mouth

2) Bile is produced by the liver and released in the small intestine to aid in the digestion and absorption of fat

3) Pancreas produces and releases pancreatic lipase to break down triglycerides into fatty acids and glycerol

4) In small intestine products of fat digestion and bile produce micelles which mover close enough to the brush border to be diffused into mucosal cells

5) In mucosal cells, fatty acids are reassembled into triglycerides and enter the lymph vessels

What are chylomicrons? (ch.5)

Lipoproteins that transport lipids from the mucosal cells of the small intestine and deliver triglycerides to other body cells. Are created via the combination of cholesterol, phospholipids and a small amount of protein.

What is the role of lipoproteins? (ch.5)

help transport dietary triglycerides, cholesterol, and fat-soluble vitamins from the small intestine and stored or newly synthesized lipids from the liver

What are the health implications of LDL? (ch.5)

High levels of LDL facilitates the delivery of cholesterol to an increased amount of cells raising the risk of cardiovascular disease.

What are the health implications of HDL? (ch.5)

High levels of HDL facilitates the removal of cholesterol from cells and transportation to the liver for elimination lowering the risk of cardiovascular disease.

What are the uses of triglycerides in the body? (ch.5)

definition of body structure, insulation from temperature changes and cushion to protect internal organs against shock via storage in adipose tissue; used to synthesize regulatory molecules in the body; regulate blood pressure, blood clotting, etc.; and stored for future use in the production of ATP via beta-oxidation

What are the essential fatty acids? (ch.5)

The essential fatty acids are linoleic acid (omega-6) and alpha-linolenic acid (omega-3)

What is the role of Omega-6 in the body? (ch.5)

important for growth, skin integrity, fertility and red blood cell structure

What is the role of Omega-3 in the body? (ch.5)

important for cell membranes of the eye and the central nervous system.

What are eicosanoids? (ch.5)

Regulatory molecules that can be synthesized from omega-3 and omega-6 fatty acids. Help blood clotting, immune function and other bodily functions.

What is lipoprotein lipase? (ch.5)

An enzyme that breaks down triglycerides into fatty acids and glycerol.

What is hormone-sensitive lipase? (ch.5)

An enzyme in adipose cells that breaks down triglycerides into fatty acids and glycerol for release in response to chemical signals.

What is atherosclerosis? (ch.5)

A type of cardiovascular disease that involves the buildup of fatty material in the artery walls.

What are some dietary lipids that promote heart disease? (ch.5)

Excessive intake of cholesterol, saturated fat, and trans fatty acids. (Most of all due to their impact on blood cholesterol levels.)

What are some dietary lipids that protect against heart disease? (ch.5)

Omega-6, Omega-3 and monosaturated fat

What are some cancers that can be indirectly caused by the over-consumption of dietary fats? (ch.5)

Breast cancer and colon cancer.

How is breast cancer related to dietary fats? (ch.5)

an excess amount of fat may serve as a tumor promoter

How does dietary fat play a role in the initiation of colon cancer? (ch.5)

bacteria that break down excess dietary fat in the colon produce tumor initiators

What is the dietary recommended intake for linoleic acid? (ch.5)

women-12 g/d

men-17 g/d

What is the dietary recommended intake for fat? (ch.5)

A total fat intake of 20-35% of kcalories for adults

What is the dietary recommended intake for cholesterol? (ch.5)

<200 mg/d

What is the dietary recommended intake for saturated fat? (ch.5)

<10% of energy

What is the dietary recommended intake for trans fat? (ch.5)

5.8g/d or 2.6% of energy intake

How would you translate information about fats into health diets? (ch.5)

Add minimum amounts of concentrated sources of fats (oils, butter, margarine, sauces and salad dressings), select foods low in trans fat, select non or low fat milk products, reduce amount of red meet in diet, select foods with a lot of monounsaturated fats (olives and avocados), remove processed foods from diet, select legumes and vegetables

What are amino acids comprised of? (ch.6)

carbon, hydrogen, oxygen and nitrogen

What are the nine essential amino acids? (ch.6)

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine

Describe the structure of protein. (ch.6)

Composed of amino acids linked together by a peptide bonds

What is the basic structure of the amino acid? (ch.6)

It consists of a central carbon attached to an amino group, acid group, hydrogen an side chain

Describe the digestive process of proteins? (ch.6)

1) Mouth begins mechanical breakdown of protein

2) HCl and pepsin begin chemical digestion

3) Protein digesting enzymes from pancreas and villi in small intestine break polypeptides into amino acids

4) Transport proteins move products of protein digestion into the mucosal cell

5) Dipeptides and tripeptides can enter the mucosal cell and are broken down into amino acids

6) Amino acids pass from mucosal cell into the blood and travel to the liver (regulates the distribution of amino acids to the rest of the body)

Describe the process of protein synthesis. (ch.6)

1) DNA is transcribed onto messenger RNA (Transcription)

2) mRNA takes information from nucleus to cytosol to be translated onto tRNA

3) tRNA reads DNA code and delivers needed amino acids to form a polypeptide (translation)

(4. Polypeptides undergo further chemical modifications before achieving their final protein structure)

What are the 8 major functions of protein? (ch.6)

Structural, Enzymes, Transportation, Protection, Contractile (muscle movement), Hormones, Regulation of fluid balance, and Regulation of acid-base balance

What is nitrogen balance? (ch.6)

The amount of nitrogen consumed in the diet compared with the amount excreted by the body over a given period

What is positive nitrogen balance? (ch.6)

When the intake of nitrogen exceeds the output. Generally occurs when new tissue is being synthesized.

What is negative nitrogen balance? (ch.6)

When the output of nitrogen exceeds the intake of nitrogen. Generally occurs when intake is too low or when the amount of protein breakdown has been increased by a stress such as injury, illness, or surgery.

What is deamination? What is the purpose of this? (ch.6)

The removal of the amino group from the amino acids. The 3-carbon compounds are formed via gluconeogenesis to synthesize by the liver.

How is protein quality measured? (ch.6)

By measuring both it's amino acid composition and digestibility

What is PDCAAS? (ch.6)

A measure of protein quality that reflects a protein's digestibility as well as the proportions of amino acids it provides

What are the diseases related to inadequate-intake of protein? (ch.6)

kwashiorkor and marasmus

What is kwashiorkor? (ch.6)

A form of protein-energy malnutrition in which only protein is deficient

What are the symptoms of kwashiorkor? (ch.6)

Hampered growth, increased susceptibility to infection, lack of melanin, nutrient absorption is impaired, and bloated belly

What is marasmus? (ch.6)

A form of protein-energy malnutrition in which a deficiency of energy in the diet causes severe body wasting.

What are the consequences of excessive consumption of protein? (ch.6)

impairment of hydration and kidney function, bone health, development of kidney stones, heart disease and cancer risk

What are the symptoms of marasmus? (ch.6)

general starvation: muscle and fat wasting, poor growth, little disease resistance, slowed metabolism, and impaired brain development

How do you calculate the amount of protein required by an individual? (ch.6)

1. Convert weight of individual from pounds to kilograms

2. Multiply weight by 0.80

What are the health risks of protein and amino acid supplements? (ch.6)

Weight gain, dehydration, can cause the deficiency of other amino acids that share the same transport system

What is nutritional genomics? (ch.1)

the study of how diet affects our genes and how individual genetic variation can affect the impact of nutrients or other food components on health