NR 228 Week 2
monosaccharide
basic unit of a carbohydrate made of Carbon, Hydrogen and Oxygen atoms
glycogenolysis
breakdown of glycogen to glucose
short chain fatty acids
can be absorbed and used for energy by the mucosa of the colon, thereby maintaining the health of the colon epithelial cells increase fecal matter bulk
glycogen
carbohydrate energy stored in the liver and in muscles
1-3%
carbohydrates are _____ of our body mass
lactose
composed of glucose and galactose
polysaccharides
consist of many units of monosaccharides joined together starch and fiber glycogen stored in the liver and muscles
dietary fiber
consists of substances in plant foods, including carbohydrates and lignin, that for the most part cannot be digested by humans
maltose
created when two units of glucose are linked available when cereal grains are about to germinate and the plant starch is broken down into ______ glucose and glucose
must be digested
disacchrides _____ and turned into monosaccharides before they can be used by the body
soluble dietary fiber
dissolve in fluids, include pectin, mucilage, psyllium seed
epinephrine
enhances the fast conversion of liver glycogen to glucose
brush-border cells
enzymes specific for disaccharides are secreted by the small intestine's _________, which then hydrolyze disaccarides into monosaccharides
glycolysis
first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid this happens in the cytoplasm of a cell
aspartame
formed by the bonding of the amino acid phenylalanine and aspartic acid digested and absorbed as two separate amino acids NutraSweet and Equal
steroid hormones
functions against insulin and promote glucose formation from protein
advantages of sugar alcohols
have several advantages when used to replace sugar less cariogenic than sucrose longer absorption time leads to a slower rise in blood sugar or reduced glycemic response good for diabetics
insulin
hormone produced by the beta cells of the islets of langerhans, lowers blood glucose levels by enhancing the conversion of excess glucose to glycogen through glycogenesis or to fat stored in adipose tissue also eases the absorption of glucose into the cells so the use of glucose as energy is increased
protein sparing effect
if enough carbohydrate is provided to meet the energy needs of the body, protein can be spared or saved to use for specific protein functions
disadvantage of sugar alcohols
if large quantities are consumed, they may ferment in the intestinal tract because of their slower absorption rate may cause gas and diarrhea
saccharin
in animals excessive consumption and the development of bladder cancer restrictions include that beverages may contain no more than 12 mg/oz or less than 30 mg per food serving Sweet N Low
ketones
intermediate products of fat metabolism
sucrose
is formed from the pairing of units of glucose and fructose table sugar
simple carbohydrates
monosaccharides and disaccharides
without
monosaccharides can be absorbed in the body ______ any digestion
cellulose
polysaccharide consisting of glucose monomers that reinforces plant-cell walls humans have a hard time breaking cellulose down so it is primarily fiber
linear or branched
polysaccharides can be either _____ or ______
70 and 100 mg/dL
primary aspect of carbohydrate metabolism is the maintenance of blood glucose homeostasis between _______
glycogenesis
process of converting glucose to glycogen
insulin inhibitors
produced by the pituitary gland, growth hormone and ACTH function as _________
glucogenic
producing glucose
galactose
rarely found in nature by itself but is part of the disaccharide lactose, the sugar found in milk
somatostatin
secreted from the hypothalamus and pancreas, inhibits the functions of insulin and glucagon
three concerns about sugar
sources in the food supply consumption levels health effects
complex carbohydrates
starches found in grains, potatoes, and vegetables fiber
glucagon
stimulates conversion of liver glycogen to glucose, assisting the regulation of glucose levels during the night
starch
storage form of plant carbohydrate
Acesulfame K
synthetically produced, 200 time sweeter than sucrose, not digestible by the human body Sunnette
glycemic load
the amount of carbohydrate in a food multiplied by the glycemic index of the carbohydrate
90 g
the amount of glycogen held in the liver
150 g
the amount of glycogen held in the muscles
glucose
the liver removes fructose and galactose and converts them to _________ blood sugar the form of carbohydrate most easily used by the body
energy
the only real nutrient function of carbohydrates carbohydrates most efficient form
gluconeogenesis
the process of producing glucose from fat not as efficient as using carbohydrate directly for glucose
Glycemic index
the ranking of foods according to the level to which a food raises blood glucose levels compared with a reference food such as a 50-g glucose load
fructose
the sweetest of the sugars provides the characteristic taste of fruits and honey
portal blood circulatory system
transports glucose, fructose, and galactose to the liver
vitamins synthesized by colonic bacteria
vitamin K, biotin, B12, folate, and thiamin only vitamin K and biotin can be absorbed in sufficient amount from the colon to be significant
metabolic water
water generated in the tissues during the chemical breakdown of the energy-yielding nutrients in foods approx 200 mL
100g
we must use about _____ of carbohydrates as glucose for brain function
ketone bodies
Breakdown products from fat catabolism in cells; also called acetones
oligomer
Short chain of monomers that is not long enough to be considered a polymer.
type 2 diabetes mellitus
a form of diabetes mellitus in which the pancreas produces some insulin that is defective and unable to serve the complete needs of the body
phenylketonuria (PKU)
a genetic disorder in which the essential digestive enzyme phenylalanine hydroxylase is missing
sucralose
a nonnutritive sweetener, suitable for cooking, that provides no energy Splenda
Beta carotene
a substance the body can convert into vitamin A, may have a protective effect against some forms of cancer
keto-acidosis
affects the pH balance of the body, which can be lethal if uncontrolled
sugar alcohols
also called sugar replacers avoid confusion with noncarbohydrate alcohol, are nutritive sweeteners because they provide 2 to 3 kcal/g but fewer than 4 kcal/g
microflora
although human digestive juices cannot diges fiber, ___________________ that normally reside in the colon use fiber as a medium for microbial fermentation, resulting in the synthesis of vitamins and the formation of short-chain fatty acids
DRI for carbohydrates
130 g/day for adults between 19 and 30
AMDR for carbohydrates
45-65%
hexose
6 carbon sugar (glucose, fructose, galactose)
disaccharide
A double sugar, consisting of two monosaccharides joined by dehydration synthesis. maltose, sucrose, lactose
polymer
A long molecule consisting of many similar or identical monomers linked together.