park-macronutrions Flashcards
(25 cards)
carbohydrates as energy source
major energy source for humans
used to generate many metabolic intermediates
excess carbs are converted to
glycogen
triacyglycerol
simple carbs
sugars
fruits, veggies, and milk
monosaccharides
disaccharides
monosaccharides
single sugar molecules (CHO)
glucose, fructose, galactose
disaccharides
two sugar molecules combined
sucrose, lactose, maltose
complex carbohydrates
polysaccharides
many monosaccharides linked together in chains
glycogen in animals, and starch and fiber in plants
monosaccharides
glucose
fructose
glucose
aka dextrose
the most important carb fuel for the body
frequently referred to as blood sugar
rarely occurs as a monosaccharide in food; part of a disaccharide or starch
fructose
found in fruits and vegetables; more than half the sugar in honey
does ot cause as great a rise in blood as other sugars, but causes an increase in blood lipids
the dramatic increase in the use of high-fructose corn syrup has been suggested to be related in the increased incidence of diabetes and obesity
digestion of carbs
a-amylase
enzymes on the luminal surface of small intestine
only monosaccharides are absorbed in the body
a-amylase
hydrolyzes starch and glycogen to maltose and maltotriose
exists in saliva and pancreatic juice
maltase (a-glycosidase)
maltose and maltriose into glucose
sucrase
sucrose into glucose and fructose
lactase
lactose into glucose and galactose
lactose intolerance occurs when lactase is not produced enoguh
indigestible carbohydrates
converted to monosaccharides ny bacterial enzymes.
metabolized anaerobically by bacteria
result in production of short-chain fatty acids, lactate, H2, CH4, and CO2.
may cause flatuence and abdominal discomfort.
raffinose
oligosaccharide in leguminous seeds (beans and peas)
cannot be hydrolyzed by human enzymes
glycemic index
measure of how quickly individual foods will raise blood glucose level.
defined as the ratio of the area of the blood glucose response curve to that of glucose
high glycemic index
raise the blood glucose the most
low glycemic index
least amount increase of blood glucose
highest GI
pure glucose solution
cellulose and hemicellulose
unrefined cereals, bran, whole wheat
insoluble
increase stool bulk and decrease intestinal transit time
lignin
woody parts of vegetables
insoluble
binds cholesterol and carcinogens
pectin
fruits
soluble
decreases rate of sugar uptake and decrease serum cholsterol
lipids in diet
efficient source of energy
provides satiety
adds flavor and aroma to diet
carrier for fat-soluble vitamins
triacylglycerol is > 90% of dietary fat
phospholipids, cholesterol, cholesterol esters, fatty acids are <10% of dietary fat
