Midterm Prep Flashcards
genome:
the full complement of genetic material in the chromosomes of a cell.
genes:
units of a cell’s inheritance, made of the chemical DNA (deoxyribonucleic acid). Each gene directs the making of one or more proteins, which perform important tasks in the body.
nutritional genomics:
the science of how nutrients affect the activities of genes and how genes affect the activities of nutrients. Also called molecular nutrition or nutrigenomics.
energy:
the capacity to do work. The energy in food is chemical energy; it can be converted to mechanical, electrical, heat, or other forms of energy in the body. Food energy is measured in calories.
Nutrients that contain carbon and thus are organic
Carbohydrates, fat, protein, vitamins
Some roles of vitamins and minerals
digesting food; moving muscles; disposing of wastes; growing new tissues; healing wounds; obtaining energy from carbohydrate, fat, and protein; and participating in every other process necessary to maintain life.
Calories per gram of fat, carbohydrates, protein
fat = 9 protein&carbs = 4
Elemental diets
diets composed of purified ingredients of known chemical composition; intended to supply all essential nutrients to people who cannot eat foods.
Nonnutrients
compounds other than the six nutrients that are present in foods and have biological activity in the body.
Phytochemicals
nonnutrient compounds in plant-derived foods that have biological activity in the body (phyto means “plant”).
nutraceutical
a term used to describe a product that has been isolated from food, often sold in pill form and believed to have medicinal effects
partitioned foods
foods composed of parts of whole foods, such as butter (from milk), sugar (from beets or cane), or corn oil (from corn). Partitioned foods are generally overused and provide few nutrients with many Calories.
legumes:
beans, peas, and lentils, valued as inexpensive sources of protein, vitamins, minerals, and fibre that contribute little fat to the diet.
foodways
the sum of a culture’s habits, customs, beliefs, and preferences concerning food.
4 methods of collecting diet information
diet history, food diaries, 24‑hour food recall, and food frequency analysis.
4 types of epidemiological studies
population
historical
case-control
cohort
dietary reference intakes (DRI)
a set of five lists of nutrient intake values for healthy people in Canada and the United States. These values are used for planning and assessing diets:
RDA
recommended dietary allowances (RDA) nutrient intake goals for individuals; the average daily nutrient intake level that meets the needs of nearly all (97% to 98%) healthy people in a particular life stage and gender group.a Derived from the estimated average requirements
AI
adequate intakes (AI) nutrient intake goals for individuals; the recommended average daily nutrient intake level based on intakes of healthy people (observed or experimentally derived) in a particular life stage and gender group and assumed to be adequate.a Set whenever scientific data are insufficient to allow establishment of an RDA value.
UL
tolerable upper intake levels (UL) the highest average daily nutrient intake level that is likely to pose no risk of toxicity to almost all healthy individuals of a particular life stage and gender group. Usual intake above this level may place an individual at risk of illness from nutrient toxicity.
EAR
estimated average requirements (EAR) the average daily nutrient intake estimated to meet the requirement of half of the healthy individuals in a particular life stage and gender group; used in nutrition research and policymaking and the basis upon which RDA values are set.
AMDR
acceptable macronutrient distribution ranges (AMDR) values for carbohydrate, fat, and protein expressed as percentages of total daily caloric intake; ranges of intakes set for the energy-yielding nutrients that are sufficient to provide adequate total energy and nutrients while reducing the risk of chronic diseases.
DV
Daily Values (DV) nutrient standards used on food labels, in grocery stores (and on some restaurant menus and websites in Canada and the United States). The DV allow comparisons among foods with regard to their nutrient contents.
Daily values of carb, fat, protein
■45 to 65 percent from carbohydrate
■20 to 35 percent from fat
■10 to 35 percent from protein
EER
Estimated Energy Requirement (EER) the average dietary energy intake predicted to maintain energy balance in a healthy adult of a certain age, gender, weight, height, and level of physical activity consistent with good health.
Two guidelines
1) Nutritious foods are the foundation for healthy eating.
2) Processed or prepared foods and beverages that contribute to excess sodium, free sugars, or saturated fat undermine healthy eating and should not be consumed regularly.
HEI
Healthy Eating Index (HEI) a dietary assessment tool that evaluates a diet’s adherence to the principles of the USDA Food Guide and the Dietary Guidelines for Americans, as well as the variety of foods the diet contains.
Why use DRI
.to set nutrient goals for individuals
b. to suggest upper limits of intakes, above which toxicity is likely
c. to set average nutrient requirements for use in research
Examples of sources of unsaturated fatty acids
Olives, nuts, vegetable oil
Which vitamin and mineral daily values must be stated?
Vitamin A, C, calcium, iron
Hunger horomone
grehlin
Chyme
the fluid resulting from the actions of the stomach upon food.
Bile
a cholesterol-containing digestive fluid made by the liver, stored in the gallbladder, and released into the small intestine when needed. It emulsifies fats and oils to ready them for enzymatic digestion
Duodenum
the first part of the small intestine, the site at which foods are subjected to the action of bile and pancreatic juices and where the breakdown of proteins, carbohydrates, and fats begins
jejunum
the first two-fifths of the small intestine beyond the duodenum. Its principal function is absorption of digested material
Ileum
the last segment of the small intestine that precedes the large intestine and functions in the absorption of nutrients
Enzymes
specialized proteins that facilitate the conversion of one substance into another without the enzyme being altered. They are vitally important in thousands of chemical reactions in the body. Digestive enzymes break down food into small molecules that can be absorbed.
Phagocytes
white blood cells that can ingest and destroy antigens in a process known as phagocytosis.
glycogen
a highly branched polysaccharide composed of glucose that is made and stored by liver and muscle tissues of human beings and animals as a storage form of glucose. Glycogen is not a significant food source of carbohydrate and is not counted as one of the complex carbohydrates in foods.
chelating
agents molecules that attract or bind with other molecules and are therefore useful in either preventing or promoting movement of substances from place to place.
Role of insulin
After a meal, the blood glucose level rises. Insulin is secreted by the pancreas to reduce the blood glucose level by
increasing the permeability of cell membranes, which allows glucose to enter the cells. Insulin serves as a “key,” allowing glucose to go through the cell “door.”
stimulating the production of energy from glucose in the cells.
facilitating the conversion of glucose to glycogen in the muscle and liver cells.
facilitating the conversion of glucose to fat in the liver cells. Insulin also stimulates fat cells to take up and store fat.
Glucagon
Between meals, the blood glucose level drops. Glucagon is secreted by the pancreas to increase the blood glucose level by
facilitating the conversion of glycogen stored in the liver to glucose, which enters the bloodstream and circulates to the brain and other parts of the body.
stimulating the conversion of body protein to glucose (gluconeogenesis) and energy if the glycogen store in the liver is exhausted.
The dietary monosaccharides include
fructose, glucose, and galactose
Three classes of dietary lipids
Triglycerides, phospholipids, sterols
chylomicrons
clusters formed when lipids from a meal are combined with carrier proteins in the cells of the intestinal lining. Chylomicrons transport food fats through the watery body fluids to the liver and other tissues.
The fat soluble vitamins are
A, D, E, K
Vegetable and fish oils are rich in
Polyunsaturated fat
DRI recommended intakes for protein:
Pounds / 2.2 = kilograms * 0.8 = grams of protein recommended
■Acceptable Macronutrient Distribution Range (AMDR) is 10–35% of total energy
■0.8 g protein per kilogram of body weight per day
■Women: 46 g /day; men: 56 g /day
10 functions of proteins
Acid-base balance, antibodies, blood clotting, energy, enzymes, fluid and electrolyte balance, growth and maintenance, hormones, transportation, vision
adipose tissue
Adipose tissue performs several functions, including the synthesis and secretion of the hormone leptin involved in appetite regulation.
basal metabolism
the sum total of all the involuntary activities that are necessary to sustain life, including circulation, respiration, temperature maintenance, hormone secretion, nerve activity, and new tissue synthesis, but excluding digestion and voluntary activities. Basal metabolism is the largest component of the average person’s daily energy expenditure.
Estimate of energy need
kg body weight X (men24, women 22) = cal/day
An essential nutrient is nto
Synthesized by the body in sufficient quantity
Nutrition is defined as
The study of the function and interaction of nutrients and the processes by which the body uses them
AMDR for fat
20 to 35 percent of energy
An ounce is how many grams?
28grams
A tablespoon is _ bigger than a teaspoon
3
Function of the pyloric sphincter
Prevent intestinal contents from backflowing into the stomach, and hold the food in the stomach so that it can be liquefied and mixed to form chyme
Sequence of intestine segments
Duodenum, jejunum, ileum, colon, rectum (DJ IC R)
Mouth enzyme for starch
amylase
Three disaccharides
Maltose, sucrose, lactose
Average carb intake
50 to 55 percent of energy
RDA grams of carbs
130 grams
After absorption into the mucosal cells, long-chain fatty acids
are reassembled to form new triglycerides
Which vitamin is synthesized from cholesterol?
Vitamin d
Hydrogenation
Makes unsaturated fats more solid, has some double bonds changed to the trans form, it prevents oxidation of fat
The human adult requires how many essential amino acids?
about 9
After digestion of protein in the stomach you get
Large and small polypeptides
A limiting amino acid is
the essential amino acid found in shortest supply relative to the amount needed for protein synthesis
Ketones are produced when
fats are metabolized to produce energy for the body
Fats and carbohydrates are composed of
Hydrogen, oxygen, carbon
Proteins are composed of
Carbon, Oxygen, Hydrogen, Nitrogen, Sulfur
Functions of fat
store energy, fuel, padding/insulation, cell membranes, raw material
Liquid at room temperatures fats are
Unsaturated
Linoleic vs linolenic
omega 6 vs nic is 3
Negative nitrogen balance =
output exceeds intake
BMI formula
kilograms over metres squared
Five features of a well designed study
Large enough, random placement, both groups should match, placebo resembles the active treatment, double-blind
Key nutrients in each food group
Fruits - vitamins, C and potassium Vegetables - vitamin A, folate, Grains- fibre, enriched Protein- iron, zinc Dairy, phosphorus, vitamin d
BMI groupings
Underweight - <18.5
Normal 18.5-24.9
Overweight 25-29.9
Obese 30+
