Chapter 4: Carbohydrates Flashcards
Lactose intolerance:
Occurs as a result of insufficient lactase or low lactase. Lactose molecules from milk remain, providing food for bacteria in the large intestine. Symptoms include bloating, abdominal discomfort, gas, diarrhea
Glycemic index:
The measure of the extent to which a particular food can raise the blood glucose concentration and elicits an insulin response compared to pure glucose.
Hypoglycemia:
When blood glucose levels are below normal levels
Hyperglycemia
When blood glucose levels are elevated
Monosaccharides:
Single Sugars.
1) Glucose: basic sub-unit of larger carb molecules. Blood sugar
2) Fructose: sweetest of all single sugars
3) Galactose: Combines with glucose to make lactose
Disaccharides:
Pairs of Monosaccharides. The linking of 2 monosaccharides produces a disaccharide. Alpha and beta bonds.
1) Sucrose (table sugar): glucose+fructose alpha bond
2) Lactose: glucose+galactose beta bond
3) Maltose: glucose+glucose alpha bond
Polysaccharides
Long carbohydrate chains of monosaccharides (100-1000 of glucose molecules) linked by alpha or beta bonds. Some are digestible, others not.Depends on whether it is alpha or beta bond
Different between simple and complex carbs
Simple carbs are made of 1 or 2 sugars that are digested quickly. Example: fruits, high fructose corn syrup
Complex carbs are made up of many sugar units and take longer to be broken down. Example: brown rice
Functions of carbs
Digestible carbs:
Energy: carbs are the most efficient energy form.
Sparing body protein: inadequate carb consumption causes body to break down amino acids
Preventing Ketosis: Some carb intake is necessary to complete breakdown of fat to CO2 and H2O
Indigestible carbs:
Promotes bowel health: Insoluble fibers aid in enlarging stool size
Promotes weight control: suluble fiber fills you up without contributing many calories
Enhances blood glucose control: slow glucose absorption
Reduces Cholestrol Absorption
What happens if individual has less than 50g of carbs
Body protein will be used to make glucose. Result is ketosis
Outline the process of carbohydrate digestion and absorption
Chewing initiates mechanical digestion
Salicary amylase begins digestion of starch
Fibers remain in stomach longer, delaying gastric emptying
Pancreas secrets pancreatic amylase which breaks down starch into short glucose chains
Enzymes complete digestion
Indigestible carbs cannot be broken down by enzymes, so they pass to large intenstine and broken down by bacteria
Of all carbs only monosaccharides can be absorbed
Absorbed by active transport or facilitated diffusion
Travel in portal vein to liver
Excess glucose converted to fat
Name the 2 dietary fibers and their functions, examples of each
Insoluble fiber: More resistant to being broken down by bacteria. Do not dissolve in water Whole grains, outer skin of vegetables and fruits
Soluble fiber: Dissolve easily in water and become gel like in consistency. Readily digested by intestinal bacteria. Oat bran, fruits, legumes
Dietary changes an individual with lactose intolerance should make
Gradual increases in milk intake
For calcium, eat canned fish with bones, brocolli, cauliflower
For Vitamin D, 15 minutes exposure to sunlight few times per week. Fatty fish
For Riboflavin, beef chicken liver mushrooms egg
Difference between type I and type II Diabetes
Type I Diabetes:
- 5-10% of patients
- Due to an autoimmune disorder that destroys insulin producing cells
- Begins in late childhood, genetic link
- Treatment is insulin injections diet and exercise
Type II Diabetes:
- 90% of patients
- Inability of the body’s cells to respond to insulin
- Risk factors include obesity, physical inactivity, consumption of rich refined food
- Treatment is liftestyle modification
Why sugar from fruit is better than sugar from soda
Fruit is packed with nutrients because it is a natural sugar
