Carbohydrates Flashcards
What are carbohydrates comprised of ?
Carbon, hydrogen and oxygen
What is glycogen ?
A stored form of glucose in the muscle or liver that helps to maintain blood glucose levels. When glucose levels begin to decline in the blood, glycogen is converted to glucose.
What are glucose, fructose and galactose all examples of ?
Monosaccharides or simple sugars commonly found in foods. Much of the glucose in our diet is a result of the breakdown of starches and other sugars. Much of the glucose in our diet is a result of the breakdown of starches and other sugars.
What are sucrose, lactose and maltose examples of ?
These are all disaccharides or two monosaccharide units joined together. Sucrose = glucose + fructose it is very sweet and is found in table sugar, honey and maple syrup. Lactose = glucose + galactose known as the milk sugar. Maltose = glucose + glucose and it is rarely found in food. Maltose is used in the liquor industry to convert sugar to alcohol.
What is starch, fiber and glycogen examples of ?
These are all polysaccharides or complex carbohydrates.
What is the storage molecule of carbohydrates in plants ?
Starch - sources include vegetables, beans, breads, pasta and rice.
Fiber is indigestible true or false …….
True- this complex carbohydrate cannot be digested.
What are the three types of fiber ?
- Insoluble (nonfermentable)
Does not dissolve in water
Not broken down by intestinal bacteria
Increases the stool mass
Speeds passage through the large intestine
- Soluble (viscous)
Does dissolve in water
Is broken down by intestinal bacteria
Slows glucose absorption and can lower cholesterol
Provides satiety to a meal
- Functional
Fiber that is added to a product
Promotes intestinal health
Sources of carbohydrates
Fruits, vegetebles, breads, pasta and dairy products have more nutritional value than
other sources of carbs such as jams, , jelly, honey, soda, desserts
Starches such as dried beans, peas, whole grains -
Often the foods that are high in starch are also good sources of fiber.
Walk through the carbohydrate digestive process…
Digestion of carbohydrates begins in the mouth. Salivary amylase (an enzyme released from the salivary glands) begins to break down starch into disaccharides. In the stomach, the acidic environment deactivates the amylase and no digestion occurs. Remember that most digestion occurs in the small intestine and this is true with carbohydrates. The pancreas releases pancreatic amylase to break down the polysaccharides to mono and disaccharides. The wall of the small intestine also has specialized enzymes that break down the disaccharides to monosaccharides. Maltase digests maltose and the results are two glucose units. Sucrase digests sucrose and yields glucose and fructose. And the third enzyme is lactase which digests lactose to produce glucose and galactose. Some individuals lack the ability to produce lactase, or make limited amounts, which results in an inability to break down lactose. Symptoms include bloating and abdominal gas formation after ingestion of dairy products. The condition is referred to as Lactose Intolerance. Most individuals with this condition can tolerate cheese and yogurt and a small amount of milk.
Most monosaccharides are actively absorbed. This means that they require a carrier protein and energy to be absorbed from the small intestine into the cells. Fructose uses facilitated absorption to be taken up by the cells. With facilitated absorption, a carrier protein is required but no energy is needed.
After absorption, the monosaccharides are transported to the liver and either released as glucose into the blood stream, stored as glycogen for later use or used for fat production. The fat production only occurs if there is excess calorie and carbohydrate consumption.
Functions of Carbohydrates
Carbohydrates are used as the body’s go to fuel source… Glucose is needed in order to create ATP which the body uses as its main source of energy for metabolic and cellular activities.
What is gluconeogenesis ?
The conversion of protein to glucose to be used as fuel. This happens when the body takes in inadequate amounts of carbohydrates.
Talk about the regulation blood glucose levels
While eating a meal and immediately afterward, your blood glucose levels begin to rise. The counter actions of glucagon and insulin keep the blood sugar levels within the optimal range. Insulin, produced and released by the pancreas, decreases the blood glucose level while glucagon, also produced and released by the pancreas, increases the blood sugar level.
What is the recommended blood sugar range?
Between 70 and 100 mg/dl.
What are the two actions that occur with the release of insulin?
Number one, the liver takes up glucose from the blood and stores it as glycogen.
And the second: muscles, adipose tissue and various cells absorb the glucose into their cells. The result, blood sugar declines to the normal range.
