Midterm

Question 1

What is meant by the word nutrition?

Answer 1

Nutrition is the science that links food to health and disease.

Question 2

How does nutrition affect our health? What are some health problems that are affected by nutrition?

Answer 2

Nutrients are building blocks that are vital to growth and development, and without them, the body will not be able to perform various essential processes.

Vitamin C and Scurvy.
Calcium and Osteoporosis.

Question 3

What is a deficiency disease?

Answer 3

A disease or deficiency that is caused by a lack of a particular nutrient.

Question 4

What are the 6 categories of nutrients? Describe each briefly, and tell why each is needed by the body.

Answer 4

Lipids - fats and oils; needed for cell membranes and energy storage.
Carbohydrates - sugars and fibers; main energy source.
Proteins - proteins; enzymes, and other cells.
Vitamins - fat and water soluble varieties; enable chemical reactions.
Minerals - inorganic substances; used to build various structures such as calcium in bones or potassium in action potentials.
Water - solvent and lubricant; human body is about 60% water.

Question 5

Discuss internal and external cues that trigger eating.

Answer 5

Hunger is primarily the physiological drive to eat, triggered by low blood glucose levels, or an empty stomach. Appetite is the psychological drive to eat and can be triggered by anything that an individual associates with food such as a smell or a habit.

Question 6

Describe physiological factors that affect hunger, appetite, & satiety.

Answer 6

Low blood glucose can signal to the body that it needs more nutrients, while the smell of chocolate can get the stomach churning and increase desire to eat. The fatty taste and feel of a bar of chocolate can trigger leptin to be released from adipose cells to signal satiety.

Question 7

Describe the process of digestion. Go through each organ that is involved in digestion and describe what it does. Follow a meal through the GI tract and describe the digestive processes for proteins, CHO, and fats.

Answer 7

Beginning in the mouth, salivary amylase begins to break down the carbohydrates in the food. The teeth help grind up the food into smaller pieces. Then the food travels down the esophagus into the stomach where everything is soaked in HCl. Proteins begin to be denatured and some breakdown of lipids and carbohydrates is done. Bit by bit small portions are allowed into the small intestine, into which the gall bladder secretes bile that was manufactured in the pancreas to emulsify lipids. The pancreas and liver also secrete various enzymes that help to break down the carbohydrates and proteins. These nutrients, once broken down into monomers, are absorbed through the small intestine. Some vitamins are also absorbed here. The food moves from the small intestine to the large intestine where more water is absorbed as well as more minerals and vitamins. Some fat is absorbed here. The remaining undigestible stuff is moved to the rectum for excretion.

Question 8

Describe CHO digestion and absorption.

Answer 8

Most large CHO molecules are broken down into monosaccharides by the corresponding enzyme that is secreted into the small intestine by the pancreas or liver. Then, the monomers are absorbed into the blood stream and carried to the liver through the portal system, where all non-glucose molecules are converted into glucose.

Question 9

Describe how nutrients are absorbed from the small intestine into the blood and lymph.
Why are the villi important?

Answer 9

Once broken down, nutrients are passed across the cell membrane of the villi and microvilli in various ways. Water is moved through aquaporins. Some compounds like fructose are carried with facilitated diffusion. Vitamins and minerals are small enough to diffuse through the cell membrane into the blood stream. Amino acids are attached to carrier proteins and then moved into the blood or lymph, depending on size, and then are reassembled. Villi and microvilli are essential because they maximize the amount of absorptive surface area available to acquire nutrients.

Question 10

What are the RDAs? DRIs? What are they used for?

Answer 10

Recommended Daily Allowance, Dietary Reference Intakes. They are used to approximate what the human body needs on a daily basis as well as what amounts are safe for consumption.

Question 11

Know how to read and use food labels. Know how to use RDA, DRI, etc charts in book.

Answer 11

Look at a food label

Question 12

Draw and discuss the myplate guideline.

Answer 12

My plate

Question 13

What have been some criticisms of the myplate and the dietary guidelines? Especially, how does the new research on fats support or not support these guidelines?

Answer 13

The my plate dietary guideline does not take differences in gut flora and fauna into consideration as well as various alternatives to the traditional composition of the diet. Now that cholesterol is no longer a nutrient that one must avoid, this allows for a slightly higher fat intake compared to the last my plate update.

Question 14

Be able to calculate percentage of kcals from fat, given grams of fat and total calories. Calculate calories in food given grams of protein, CHO, fat, alcohol.

Answer 14

Okay

Question 15

Be able to calculate which food (of those given) gives you more of a given nutrient per calories, given nutrition and calorie information.

Answer 15

Carbohydrates 4 kcal/g
Lipids 9 kcal/g
Protein 4 kcal/g
Alcohol 7 kcal/g

Question 16

What are the 3 sources of CHO in our diet?

Answer 16

Starch, Fiber, Simple Sugars

Question 17

Be able to recognize chemical drawings of monosaccharides, glycerol, triglyceride, fatty acids.

Answer 17

Okay

Question 18

What are the 3 monosaccharides in our diet? Where found?

Answer 18

Glucose - general sugar
Fructose - fruit sugar
Galactose - milk sugar

Question 19

What are the 3 disaccharides in our diet? Where found? What are the monosaccharide units of which they are composed?

Answer 19

Sucrose (Fru+Glu) - table sugar
Maltose (Glu+Glu) - malt sugar
Lactose (Gal+Glu) - milk sugar

Question 20

Describe in detail the regulation of blood glucose. Which hormones do what?

Answer 20

Glucagon is a hormone made in the pancreas that stimulates the breakdown of glycogen into glucose so that it is readily available to use. Insulin is a hormone secreted by the pancreas that signals the body to begin to pull glucose from the blood and build glycogen.

Question 21

Describe Type I diabetes – what is it?

Answer 21

An autoimmune disorder where the body’s immune system attacks the beta-cells of the pancreas that secrete insulin.

Question 22

Describe Type II diabetes. What is metabolic syndrome, or syndrome X? What causes it?

Answer 22

Insulin resistance commonly resulting from obesity.

Question 23

What is dietary fiber? What is meant by soluble and insoluble fiber? How does each contribute to health?

Answer 23

Dietary fiber is fiber found in foods. Soluble, or viscous fiber is digestible and slows stomach emptying and glucose absorption. Insoluble, or non fermentable fiber is fiber that cannot be digested, and encourages the movement of the bowels.

Question 24

What is the glycemic index?

Answer 24

Glycemic index is the blood glucose response of a given food, compared to a standard. Glycemic index is dependent on food structure, composition and macronutrient content.

Question 25

What do we mean when we say a fatty acid is saturated?

Answer 25

There are no C=C bonds. All carbons are full of hydrogens.

Question 26

What are trans fatty acids?

Answer 26

Trans fatty acids are unsaturated fatty acids where the two hydrogens across the double bond are completely opposite one another rather than across the double bond. This gives fatty acid the straight, pseudo-saturated shape.

Question 27

Which 2 fatty acids are considered to be essential?

Answer 27

Alpha-linolenic acid (omega-3) and linoleic acid (omega-6) are considered essential.

Question 28

What foods contain cholesterol?

Answer 28

Animal meats. Especially red meats.

Question 29

Describe the process of fat digestion and absorption

Answer 29

Until reaching the small intestine, fats do not go through much breakdown. Once in the small intestine, bile that was secreted into the gall bladder where it was concentrated, is secreted from the gall bladder into the small intestine where it acts as an emulsifier, breaking the larger lipid globules into smaller bits. These bits are the collected by carried proteins and then moved across the cell membrane of the villi of the small intestine and into either the lymph, for larger molecules, or blood for small amino acids.

Question 30

How are cholesterol and lipoproteins related to CAD?

Answer 30

Coronary Artery Disease, or a restricting of blood flow through the arteries can result from a build up along the walls of the arteries of cholesterol and lipoproteins, such as low-density lipoprotein, that got stuck there when they were attracted by the weakening of an artery wall.

Question 31

What are the risk factors for CAD? Which of these are related to diet?

Answer 31

Obesity, diabetes, smoking are all risk factors for coronary artery disease. Obesity and Type II diabetes are related to diet.

Question 32

Describe a heart-healthy diet.

Answer 32

A heart healthy diet is one low in meats and higher in dietary fiber with plenty of fruits, vegetables and whole grains.

Question 33

Describe the process of atherosclerosis.

Answer 33

LDL scavenger cells fail to collect stray cells and are then consumed unsuccessfully by white blood immune cells. The hardening of the white blood cell over the place where the LDL stopped becomes plaque, a calcified accumulation of dead cells.

Question 34

What is hydrogenation?

Answer 34

The process by which hydrogen is forced into an oil to make it more solid at room temperature.

Question 35

What does Michael Pollan mean by nutritionism? What is his advice for healthful eating?

Answer 35

Nutritionism is the concept that foods’ value is based on the nutrients it can provide. Michael Pollan’s advice for healthful eating is to consider eating whole foods for the whole food, rather than the individual nutrients it will provide.