Carbohydrates Flashcards
(47 cards)
Monosaccharide Sugars
Fructose; Glucose; Galactose
Disaccharide Sugars
Sucrose (Fructose+Glucose);
Maltose (Glucose x 2);
Lactose (Glucose+Galactose)
Glucose as Starch in food
Branched & Unbranched
**Starch is the form of glucose in plants for humans
Glucose as Glycogen in muscle
HIGHLY BRANCHED
**allows for rapid, simultaneous breakdown and release
Glucose as Fiber in food
human enzymes can’t digest bonds
Fiber!
Indigestible polysaccharides in food.
Insoluble Fiber?
Still indigestible, but also can’t be dissolved in water
Soluble Fiber?
Still indigestible, but you can totally dissolve it in water it’s gummy and gel-like; and it’s broken down to some absorbable products in your colon microbiota
What’s sweeter fructose or glucose
fructose tastes better
Digestion role of mouth
enzymes in spit mix with food and break starch into maltose
Stomach?
stomach contributes nothing to carbohydrate digestion
Pancreatic enzymes
digest most of starch to disaccharides
intestinal enzymes
split disaccharides to monosaccharides
then monosaccharides enter capillary and get delivered to liver via portal vein
Liver?
liver converts galactose and fructose to glucose
COLON?
fiber travels unchanged to the colon (indigestible carb)
What does glucose do besides provide energy?
It builds some of the mucus that provides the protective coating in the intestinal tract; they create the carbon skeleton of non-essential amino acids, DNA & RNA
How does our body store glucose?
Blood glucose levels rise, and insulin is released to tell the cells to start taking up glucose, glucose is then stored as glycogen.
What body parts get glycogen?
2/3 muscle
1/3 liver
What happens in the absence of adequate carbohydrates?
- protein is broken down to supply glucose (breaks down muscles bc we don’t store protein)
- fat converted to ketones to provide brain with energy (leading to ketosis which disrupts acid-base balance in brain)
Carb daily requirements? [DRI]
Daily minimum of 130 grams/day (debatable)
~ 520 calories/day, 25% of 2000 calories.
USDA recommendations for carbs
300 grams, 60% of energy,
5-9 servings fruits and veggies, 6-11 servings grains
How are American’s doing at fiber-ing?
Current average fiber intake in US ~10-15 grams/day
1/4 - 1/2 of recommendation
Need for carbohydrates?
Nerve cells depend almost exclusively on GLUCOSE for energy.
Starchy foods, or complex carbohydrates are the preferred source of glucose in the diet.
Carbohydrate & body weight issues
gram for gram, carbohydrates provide fewer calories than fats.
important to differentiate refined sugar form complex carbs.
