Macronutrition Flashcards
Role of dietary carbohydrates
Major energy source for humans (4Kcal/g)
Used to generate many metabolic intermediates
Types of simple carbohydrates
Sugars, fruits, vegetables, milk
Monosaccharides
Disaccharides
Examples of monosaccharides
Glucose, fructose, galactose
Examples of disaccharides
Sucrose (glucose + fructose)
Lactose (glucose + galactose)
Maltose (glucose + glucose)
Types of complex carbohydrates
Polysaccharides
Glycogen in animals, and starch and fiber in plants
Glucose
Also known as dextrose
The most important carbohydrate fuel for the body
Frequently referred to as blood sugar
Rarely occurs as a monosaccharide in food; part of disaccharide in starch
Fructose
Found in fruit and vegetables; more than half the sugar in honey
Does not cause as great a rise in blood glucose 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
What enzyme hydrolyzes starch and glycogen to maltose and maltotriose?
Alpha-amylase
Examples of enzymes found on the luminal surface of the small intestine
Maltase, sucrase, and lactase
The conversion of maltose and maltotriose is facilitated by which enzyme?
Maltase
The conversion of sucrose to glucose and fructose is facilitated by which enzyme?
Sucrase
The conversion of lactose to glucose and galactose is facilitated by which enzyme?
Lactase
Dietary fiber found in unrefined cereals, bran, and whole wheat
Cellulose and hemicellulose
Dietary fiber that increase stool bulk and decrease intestinal transit time
Cellulose and hemicellulose
Dietary fiber that consist of the woody parts of vegetables
Lignin
