Chapter 2 Carbohydrates

Calorie

A unit of heat used to measure the energy your body uses and the energy it receives from food

Dietary importance of carbohydrates worldwide

widely available; easy to grow; low in cost; easily stored

saccharide

a simple sugar or combination of sugars; a carbohydrate

Glucose

the form of sugar that circulates in the blood and provides the major source of energy for body tissues.

Fructose

fruit sugar

honey

fructose

simple carbohydrates

monosaccharides and disaccharides

complex carbohydrates

polysaccharides

Glycogen

Storage form of glucose

Galactose

milk sugar

Sucrose

glucose + fructose (table sugar)

Lactose

glucose + galactose (milk sugar)

Maltose

glucose + glucose

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides; complex carbs

Starch

A storage polysaccharide in plants consisting entirely of glucose.

whole grains

contain the whole kernel, including the bran, germ, and endosperm

dietary fiber

plant material that cannot be digested

Dietary Fiber Benefits

Increases satiety value of foods as it is the bulk; Delay the emptying of the stomach (increases satiety); Establishes regular bowel movements; Reduces risk of heart and artery disease by lowering blood cholesterol; Regulates absorption of glucose

phytic acid

a nonnutrient component of plant seeds; also called phytate. Phytic acid occurs in the husks of grains, legumes, and seeds and is capable of binding minerals such as zinc, iron, calcium, magnesium, and copper in insoluble complexes in the intestine, which the body excretes unused.

Cellulose

Carbohydrate component of plant cell walls.

Lignin

substance in vascular plants that makes cell walls rigid

chelator

a ligand that binds to a metal to form a metal complex

Dietary fiber intake recommendations for adults

25-38g/day

gut microbiome

the bacteria and other organisms that live inside our gastrointestinal tract

Nutritive Sweeteners (sugar alcohols)

sorbitol, mannitol, xylitol (excess can cause diarrhea); contains calories

nonnutritive sweeteners

sweeteners that yield no energy (or insignificant energy in the case of aspartame).

calorie content of carbohydrates

4 calories per gram

Ketones

chemical substances that the body produces when it does not have enough insulin in the blood; caused from rapid breakdown of fat; toxic in large amounts in the body

Carbohydrate digestion begins in the

in the mouth with salivary amylase

Mastication

the act of chewing

Peristalsis

Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system.

hydrochloric acid

substance produced by the stomach; necessary for digestion of food

pancreatic amylase

An enzyme secreted by the pancreas into the small intestine that digests any remaining starch into maltose.

brush border enzymes of small intestine

break down double sugars into simple sugars and complete protein digestion

lactose intolerance

impaired ability to digest lactose due to reduced amounts of the enzyme lactase; can lead to gassy, bloating and diarrhea

DGA recommendations for added sugar

less than 10% of total calories