Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/56

Click to flip

56 Cards in this Set

  • Front
  • Back
Nutrition
the process by which certain components of food are obtained and used by the body;
process includes digestion, absorption, transportation, and cell metabolism
Nutrients
chemicals taken into the body that are used to produce energy, provide building blocks for new molecules, or function in other chemical reactions;
divided into six basic groups: carbohydrates, proteins, lipids, vitamins, minerals, water
Essential nutrients
nutrients that must be ingested because the body cannot manufacture them or is unable to manufacture adequate amounts of them
Carbohydrates
include monosaccharides, disaccharides, and polysaccharides; usually come from ingested plant material;
glucose and fructose are the most common in diet;
Complex carbohydrates
polysaccharides such as glycogen, starch, and cellulose;
starch is found in plants, glycogen is foud in the muscles and liver of animals
Triglycerides
lipids consisting of three fatty acids attached to a glycerol molecule;
often referred to as fats or oils;
make up about 95% of lipids in the diet
Saturated fats
triglycerides that have only single covalent bonds between the carbon atoms of their fatty acids;
found in the fats of meats and dairy products
Unsaturated fats
triglycerides that have one or more double covalent bonds between the carbon atoms of their fatty acids;
olive and peanut oils (monounsaturated), and fish, sunflower, corn oil (polyunsaturated)
Lecithin
a lipid that is composed of cholesterol and phospholipid;
found in high conc. in egg yolks and liver, as well as whole milk, cheese, butter, and meats
Proteins
chains of amino acids;
constructed of 20 different amino acids;
Essential amino acids
amino acids that must be contained in the diet;
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine
Nonessential amino acids
amino acids that the body can synthesize from other materials
Differentiate between complete protein and incomplete protein foods.
complete protein foods contain adequate amounts of all essential amino acids, incomplete proteins do not
Nitrogen balance
the nitrogen content of ingested protein is equal to the nitrogen excreted in urine and feces
Essential fatty acids
fatty acids that the body cannot synthesize and must be obtained through the diet; for example, linoleic acid
Vitamins
organic molecules that exist in minute quantities in food and are essential to normal metabolism;
vitamin means life-giving chemical
Essential vitamins
vitamins that cannot be produced by the body and must be obtained through the diet
Provitamin
a part of a vitamin that can be assembled or modified by the body into a functional vitamin; for example beta carotene can be modified by the body to form vitamin A
List three provitamins found in the body.
Beta carotene to vitamin A
7-dehydrocholesterol to vitamin D
Tryptophan to niacin
Coenzymes
molecules that combine with enzymes to make the enzyme functional;
many vitamins function as coenzymes
Fat-soluble vitamins
vitamins that dissolve in lipids; can be stored in the body, and thus may reach a toxic level;
vitamins A, D, E, & K
Water soluble vitamins
vitamins that dissolve in water; remain in the body only for a short time before excreted in the urine;
vitamins B, C, most others
Recommended Dietary Allowances (RDAs)
the nutrient intakes sufficient to meet the needs of nearly all people in certain age and gender groups
Minerals
inorganic nutrients that are necessary for normal metabolic functions; constitute 4-5% of total body weight and form componenents of coenzymes, a few vitamins, hemoglobin, and other organic molecules;
important in establishing resting membrane potentials and generating action potentials, adding mechanical strength to bones and teeth, act as buffers or regulators of osmotic pressure
Metabolism
the total of all the chemical reactions that occur in the body;
consists of anabolism and catabolism
Anabolism
the energy-requiring process by which small molecules are joined to form larger molecules
Catabolism
the energy-releasing process by which large molecules are broken down into smalled molecules;
begins during the process of digestion and is concluded within individual cells
Glycolysis
a series of chemical reactions in the cytosol that results in the breakdown of glucose into two pyruvic acid molecules;
divided into four phases, input of ATP, sugar cleavage, NADH production, and ATP and pyruvic acid production
Anaerobic respiration
the breakdown of glucose in the absence of oxygen to produce two molecules of lactic acid and two molecules of ATP;
divided into two phases, glycolysis and lactic acid formation
Cori cycle
the process of converting lactic acid to glucose; conversion takes place in the liver
Aerobic respiration
the breakdown of glucose in the presence of oxygen to produce carbon dioxide, water, and 38 ATP molecules;
occurs in four stages, glycolysis, acetyl-CoA formation, the citric acid cycle, and the electron-transport chain
Citric acid cycle
the third stage of aerobic respiration, also called the Kreb's cycle;
three important events occur during the citric acid cycle: ATP production, NADH and FADH2 production, and carbon dioxide production
ELectron-transport chain
the four phase of aerobic respiration, involves a series of electron carriers in the inner mitochondrial membrane
Chemiosmotic model
a process in which the chemical formation of ATP is coupled to a diffusion force (H+) similar to osmosis
Free fatty acids
between meals, triglycerides are broken down in adipose tissue and some of the fatty acids produced during this process get released into the bloodstream;
used by other tissues, esp. skeletal muscles and the liver, as a source of energy
Beta-oxidation
a series of reactions in which two carbon atoms at a time are removed from the end of a fatty acid chain to form acetyl-CoA;
metabolism of fatty acids occurs through this process
Ketogenesis
the formation of ketone bodies;
a process that utilizes acetyl-CoA
Ketone bodies
molecules that are released into the bloodstream, where they travel to other tissues, especially skeletal muscle, where they can be converted back into acetyl-CoA and enter the Kreb's cycle;
examples are acetoacetic acid, beta-hydroxybuytric acid, and acetone;
produced when acetyl-CoA exists in high conc., esp. in liver
Transamination
a tranfer of an amine group from an amino acid to the keto acid; one step in the synthesis of nonessential amino acids
Oxidative deamination
an energy producing process in which an amine group is removed from an amino acid, leaving ammonia and a keto acid and NAD+ is reduced to NADH which can then enter the electron transport chain to produce ATP
Glycogenesis
the production of glycogen;
in the presence of excess glucose, glycogen is formed, esp. in skeletal muscle fibers and the liver
Lipogenesis
the synthesis of lipids from glucose and amino acids;
this process is carried out only once excess glucose has been converted to a sufficient supply of glycogen
Glycogenolysis
the breakdown of glycogen into glucose-6-phosphate when glucose is needed
Gluconeogenesis
in the presence of insufficient liver glycogen levels and when glucose is needed, it can be synthesized from amino acids from proteins and glycerol from triglycerides
Absorptive state
the period immediately after a meal when nutrients are being absorbed through the intestinal wall into the circulatory and lymphatic systems;
lasts about 4 hours after each meal;
during this state, glucose in the circulation enters the cells to be used as an energy source; excess is stored in the liver as glycogen or additional fatty acid
Postabsorptive state
a metabolic state during which blood glucose levels are maintained by the conversion of other molecules to glucose, first glycogen from the liver and then fats from adipose tissue, and finally proteins can also be used
Metabolic rate
the total amount of energy produced and used by the body per unit of time
How long does ATP last within the body once produced?
Approximately how much energy is produced per liter of oxygen?
less than one minute;
4.8 kcal
Basal metabolic rate (BMR)
the energy needed to keep the resting body functional;
the metabolic rate calculated in expedned kilocalories per square meter of body surface area per hour;
determined by measuring oxygen consumption of an awake person who is resting and has not eaten for 12 hours
Thermic effect of food
the energy expenditure during the digestion of food and nutrients
Free energy
the total amount of energy liberated by the complete catabolism of food;
kcal/mol of food;
about 43% of energy derived from food is used, the remaining is lost as heat
Heat
thermal energy that is lost and is not available for work
Radiation
the loss of healt as infrared radiation;
for example, coals in a fire radiate infrared heat energy
Conduction
the exchange of heat between objects in direct contact with each other
Convection
a transfer of heat between the body and the air or water
Evaporation
the conversion of water from a liquid to a gaseous form, a process that requires heat