Unit 2: Ch 26 Nutrition (v2) Flashcards

Question

Gastric peristalsis

Answer 1

* When **mild** **hunger contractions** begin after stomach is empty * Increase in intensity over a period of hours * Do not affect the amount of food consumed

Answer 2

* Short-term appetite regulator * Signal that begins a meal; produces sensation of hunger * Secreted from parietal cells in **fundus of empty stomach** * Stimulates the hypothalamus to secrete **growth hormone–releasing hormon & neuropeptide Y** * Secretion ceases within an hour of eating

Answer 3

* **Aerobic respiration** * Occurs in the presence of oxygen * Completely oxidizes *pyruvic acid* to CO₂ and H₂O * **Anaerobic fermentation** * Occurs in the absence of oxygen * Reduces *pyruvic acid* to lactic acid * **Glycolysis** * Glucose (6 C) split into two *pyruvic acid* molecules (3 C)

Answer 4

Act as chemical signals from the gastrointestinal tract to the brain

Answer 5

* A lipoprotein that removes excess cholesterol from the body * Production begins in the _liver_; produces a _collapsed protein shell_ * High level of HDL is _beneficial_

Answer 6

* Most of the body’s heat comes from _exergonic chemical reactions_ (energy releasing such as joint friction, blood flow, and other movements) * **At rest** * most heat is generated by the _brain, heart, liver, and endocrine glands_ * Skeletal muscle contributes 20% - 30% of total resting heat * **During vigorous exercise** * muscles produce 30 - 40 times as much heat as the rest of the body

Answer 7

1. **Conduction**: _Transfer of kinetic energy_ from molecule–molecule as they collide with one another 2. **Evaporation**: The change from a liquid to a gaseous state. _Forced convection_ 3. **Radiation**: The emission of _infrared (IR) rays_ by moving molecules

Answer 8

Vitamin excess

Answer 9

* Deficiency of blood glucose * Causes nervous system disturbances such as weakness and dizziness

Answer 10

* Deficiency of blood glucose * Causes nervous system disturbances such as weakness and dizziness

Answer 11

* The preoptic area of the hypothalamus functions as the _body’s thermostat_ * Monitors temperature of the blood * Receives signals from peripheral thermoreceptors in the skin * Sends appropriate signals to either the **heat-loss center:** a nucleus in the anterior hypothalamus or the **heat-promoting center** in a more posterior nucleus near the mammillary bodies of the brain

Answer 12

* Long-term appetite regulator * Stimulates _glucose and amino acid uptake_ * Promotes _glycogen and fat synthesis_ * _Weaker_ effect on appetite than leptin * Secreted by _pancreatic beta cells_

Answer 13

* Absorbed by receptor-mediated endocytosis by cells in need of cholesterol for membrane repair or steroid synthesis * Digested by lysosomal enzymes to release the cholesterol for intracellular use * Levels of LDL * High LDL is a warning sign–Correlates with cholesterol deposition in arteries * Elevated by saturated fat intake, cigarette smoking, coffee, and stress

Answer 14

* Long-term appetite regulator * Informs brain on how much body fat we have * Level proportionate to one’s own fat stores * Obese people are more likely to have a receptor defect than hormone deficiency * **Secreted by adipocytes** throughout the body

Answer 15

* **Saturated fats** * **Animal origin:** meat, egg yolks, dairy products * **Unsaturated fats** * Found in nuts, seeds, and most vegetable oils * **Cholesterol** * Found in egg yolks, cream, shellfish, organ meats, and other meats * Does not occur in foods of plant origin

Answer 16

* Males = 15% body fat * Females = 25% body fat *Note: Well-nourished adult meets 80% to 90% of resting energy needs from fat*

Answer 17

* Transport lipids in _plasma_ * Coated with protein and phospholipids * Coating allows lipid to be suspended in blood * Also serves as a recognition marker for cells that absorb them * Contain cholesterol and triglycerides

Answer 18

* Insulin * Leptin

Answer 19

* Doses 10 to 1,000 times the RDA * Show no effect on performance

Answer 20

* The amount of energy liberated in the body in a given period of time (kcal/hr or kcal/day) * **Calorimeter:** a closed chamber with water-filled walls that absorb the heat given off by the body * Measured indirectly with a **spirometer** by measuring the amount of oxygen a person consumes * Metabolic rate depends on physical activity, mental state, absorptive or postabsorptive status, thyroid hormone, and other hormones

Answer 21

* Metabolism changes from hour to hour * Depending on how long since your last meal * **Absorptive (fed) state** * About 4 hours during and after a meal * Nutrients are being absorbed * Nutrients may be used immediately to meet energy and other needs * **Postabsorptive (fasting) state** * Prevails in the late morning, late afternoon, and overnight * Stomach and intestines are empty * Body’s energy needs are met from stored fuels

Answer 22

The chemical change that lies at the foundation of form and function

Answer 23

* Minerals * inorganic elements that plants extract from the soil or water and introduce into the food web * Vitamins * small dietary organic compounds that are necessary to metabolism * Neither is used as fuel * Both are essential to our ability to use other nutrients

Answer 24

* Excretion exceeds ingestion of protein * Body proteins being broken down for fuel; _muscle atrophy_ * Muscles and liver proteins are more easily broken down than others * Carbohydrate and fat intake is insufficient to meet body’s energy needs * _Glucocorticoids_ promote protein catabolism in states of stress

Answer 25

* Stimulate desire for different types of food * Endorphins: protein * Galanin: fats * Norepinephrine: carbohydrates

Answer 26

Varies about 1.8°F in a 24-hour cycle Low in morning and high in late afternoon

Answer 27

* Weight \> 20% above recommended norm for one’s age, sex, and height (US) * 30% obese * 35% overweight

Answer 28

* Short-term appetite regulator * Signal that _ends a meal_ * Secreted by **enteroendocrine cells of ileum and colon**

Answer 29

* Occurs in * athletes in resistance training * children because they ingest more than they excrete retaining protein for tissue growth * pregnant women

Answer 30

* **8 essential amino acids** that cannot be synthesized by the body * Isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine * **12** **inessential amino acids** synthesized by the body if the diet does not supply them * Cells do not store surplus amino acids for later use * When a protein is synthesized, all amino acids must be present at once * If one is missing, the protein cannot be synthesized

Answer 31

* **Complete proteins** * high-quality dietary proteins that provide all of the essential amino acids in the necessary proportions for human tissue growth, maintenance, and nitrogen balance * **Incomplete proteins** * lower quality because they lack one or more essential amino acids

Answer 32

* 12% - 15% of total body mass; 65% in skeletal muscle * Functions * Muscle contraction * Motility of cilia and flagella * Components * _Cellular membranes_: receptors, pumps, ion channels, and cell-identity markers * _Fibrous proteins:_ collagen, elastin, and keratin make up much of the structure of bone, cartilage, tendons, ligaments, skin, hair, and nails

Answer 33

Safe estimate of daily intake that would meet the nutritional needs of most healthy people

Answer 34

* Classified into 4 major categories by their _density_ * **Chylomicrons:** 75–1,200 nm in diameter * **Very low–density lipoproteins (VLDLs):** 30–80 nm * **Low-density lipoproteins (LDL):** 18–25 nm * **High-density lipoproteins (HDL):** 5–12 nm * Differences are in _composition and function_

Answer 35

* Temperature closer to the surface (oral cavity and skin) * Slightly lower that rectal temperature * Adult varies normally from 97.9° to 98.6°F * As high as 104°F during hard exercise * Fluctuates in response to processes that maintain stable core temperature

Answer 36

* Makes one feel hungry and begin eating and satisfied at end of a meal; effects last minutes to hours * Types 1. Cholecystokinin (CCK) 2. Ghrelin 3. Peptide YY (PYY)

Answer 37

Several negative feedback loops

Answer 38

* **Water soluable** antioxidant that scavenges free radicals and possibly reduces the risk of cancer * Promotes hemoglobin synthesis, collagen synthesis, and sound connective tissue structure * **Ascorbic acid**

Answer 39

* **Vitamin A excess** * anorexia, nausea and vomiting * headache and pain * fragility in the bones * hair loss * enlarged liver and spleen * birth defects * **Vitamin A deficiency** (most common vitamin deficiency) * night blindness * dry skin and hair * dry conjunctiva and cloudy cornea * increased incidence of urinary, digestive, and respiratory infections *Note: excess of vitamins B6, C, D & E can lead to _toxic hypervitaminosis_*

Answer 40

* Body synthesizes some vitamins from precursors called **provitamins** * _Niacin_ from amino acid tryptophan * _Vitamin A_ from carotene * _Vitamin D_ from cholesterol * _Vitamin K, pantothenic acid, biotin, and folic acid_ are produced by bacteria of the large intestine

Answer 41

* Vitamins C & B * Absorbed with water in small intestine * Quickly excreted by the kidneys, not stored, and seldom accumulate to excess

Answer 42

* Produced by _liver_ to transport lipids to adipose tissue for storage * Develop when triglycerides are removed from adipose tissue * Mostly comprised of cholesterol

Answer 43

* Cellulose, hemicellulose, lignin * Description * Absorbs water in intestines, softens stool, increases bulk 40% to 100%, stretches colon, and stimulates peristalsis thereby quickening passage of feces * Excessive intake can interfere with absorption of elements such as iron, calcium, magnesium, phosphorus, and other trace elements * No effect on cholesterol and LDL levels or colorectal cancer

Answer 44

* Chewing * Swallowing * Stomach filling *Note: Lasting satiation depends upon nutrients entering blood*

Answer 45

Protein synthesis and positive nitrogen balance in childhood

Answer 46

Any ingested chemical used for growth, repair, or maintenance of the body

Answer 47

* The starting point and the basis for all human form and function * Source of **fuel** that provides the energy for all biological work * Source of **raw materials** for replacement of worn-out biomolecules and cells

Answer 48

* Fats * contains almost no water, and is a **more compact energy storage substance** * Fat is less oxidized than carbohydrates and **contains over twice as much energy** (9 kcal/g) * Carbohydrates * hydrophilic, absorb water, and expand and occupy more space in the tissues * Contains less energy (4 kcal/g)

Unit 2: Ch 26 Nutrition (v2) Flashcards

(73 cards)