FN 2070: Intro to Human Nutrition - Carbohydrates

Flashcards covering key terms and concepts related to carbohydrates, their types, functions, and digestion process as introduced in FN 2070 Human Nutrition lecture.

Carbohydrate

A macronutrient recommended to comprise 40–60% of daily calories, serving as a primary energy source.

Protein Sparing

A function of carbohydrates, it protects muscles from being broken down for energy.

Ketosis

A condition resulting from the breakdown of fat, which carbohydrates help prevent.

Fiber

A type of carbohydrate that aids in the elimination of waste and promotes digestive health.

Energy Value of Carbohydrate

Provides 4 calories per gram, serving as energy for the brain, muscles, and organs.

Simple Carbohydrates

Sugars that include monosaccharides (glucose, fructose, galactose) and disaccharides (sucrose, lactose, maltose).

Complex Carbohydrates

Starches and fibers, which are polysaccharides (many sugar units linked together).

Monosaccharide

A simple sugar unit, such as glucose, fructose, or galactose.

Disaccharide

A simple carbohydrate formed by two monosaccharide units linked together.

Polysaccharide

A complex carbohydrate composed of many monosaccharide units, such as starch, fiber, and glycogen.

Glucose

The primary blood sugar and the body's #1 fuel source.

Fructose

Known as 'fruit sugar,' found in fruits and honey.

Galactose

A monosaccharide that pairs with glucose to form lactose.

Sucrose

A disaccharide composed of glucose + fructose, found in table sugar, fruits, and vegetables.

Lactose

A disaccharide composed of glucose + galactose, found in milk and other dairy products.

Maltose

A disaccharide composed of glucose + glucose, found in malted products and formed during starch breakdown.

Starch

A large polysaccharide molecule of linked glucose units, serving as how plants store energy.

Amylose

A type of starch that digests slowly, is less soluble, and is found in foods like rice.

Amylopectin

A type of branched starch that digests more quickly, is more soluble, and is found in tapioca.

Glycogen

A highly branched polysaccharide; the compact form of glucose storage in animals that can be released quickly.

Enzymes

Proteins required to break down carbohydrates, proteins, and fats into molecules the body can use.

Carbohydrase

An enzyme that breaks down carbohydrate molecules.

Peristalsis

The wave-like muscle contractions that move food through the digestive tract, for which fiber provides bulk.

Insoluble Fiber

A type of fiber that adds bulk to stool, aids in bowel regularity, and prevents constipation; does not dissolve in water (e.g., whole grains, some vegetables).

Soluble Fiber

A type of fiber that dissolves in water to form a gel-like substance, helping to lower cholesterol, regulate blood sugar, and promote fullness (e.g., oats, fruits, legumes).

Salivary Amylase

An enzyme in saliva that begins the chemical digestion of carbohydrates in the mouth.

Pancreatic Amylase

An enzyme released by the pancreas into the small intestine to break down larger carbohydrate chains.

Maltase

A brush border enzyme that digests maltose into two glucose molecules.

Sucrase

A brush border enzyme that digests sucrose into fructose and glucose.

Lactase

A brush border enzyme that digests lactose into glucose and galactose.

Mouth (Carbohydrate Digestion)

Where chemical (salivary amylase) and mechanical digestion of carbohydrates begins, breaking them into shorter polysaccharide chains.

Stomach (Carbohydrate Digestion)

Mechanical digestion of carbohydrates continues, but no chemical breakdown occurs due to stomach acid neutralizing salivary amylase.

Small Intestine (Carbohydrate Digestion)

The primary site where the majority of carbohydrate digestion occurs, involving pancreatic amylase and brush border enzymes.

Large Intestine (Carbohydrate Digestion)

Where dietary fiber and indigestible carbohydrates are metabolized by gut bacteria; remaining fiber is excreted.

Chyme

The pulpy acidic fluid consisting of gastric juices and partly digested food that passes from the stomach to the small intestine.

Brush Border Enzymes

Enzymes (Maltase, Sucrase, Lactase) found on the surface of small intestine cells that further break down disaccharides into monosaccharides.

Enterocyte

A specialized cell in the small intestine wall through which monosaccharides (glucose, fructose, galactose) are absorbed into the bloodstream.

Portal Vein

The blood vessel that transports absorbed monosaccharides from the small intestine to the liver.