Chapter 4 Flashcards
Carbohydrates (function, recommended intake, sources of)
primary function of carbohydrates:
- energy
recommended intake
- 4 kcal/g
- AMDR: 45-65%
sources:
- whole and refined grains
- fruit
- milk
- legumes
- vegetables
- nuts,seeds
carbs are in plant based foods
Whole grains VS refined grains
Whole:
- bran - protective outershell. high in fiber and vitamins
- endosperm- contains starch, protein and. vit and min. largest part
- germ- seed. source of oil and is rich in vit E
refined:
- milling removes the bran and germ.
- nutrients lost during this process
- **endosperm is left behind **
Enrichment
replacing some of the nutrients removed during refining the grain
folic acid, thiamin, niacin, riboflavin iron
not replaced? fiber, magnesium, phytochemicals, vitamin E, healthy fats
fortification
shit added to something when it was not originally in
Types of carbohydrates
carbs are made of “sugar units” containing carbon, hydrogen, and oxygen
- monosaccaharides are the elemental unit of carbs
- disaccharides= 2 monosaccharides
are both known as “simple carbohydrates” / “simple sugar”
Monosaccharides
- glucose
- galactose
- fructose
glucose is in blood. glactose is in milk. fructose is in fruits and veggies
glucose-glucose single bond= MALTOSE
glucose-fructose single bond= TABLE SUGAR
galactose- glucose single bond= LACTOSE
simple carbohydrates
Complex Carbohydrates: Polysaccharides
(storage in animals/plants)
carbohydrate storage in animals:
- glycogen
- liver & muscles
Carbohydrate storage in plants:
- starch
complex carb not capable of being broken down by human digestive enzymes:
fiber (soluble/insoluble)
Resistant starches
not digested in small intestine due to natural protective coating or alterations to sturcure with cooking
- ripe bananas
- legumes
- cold cooked potatoes
- rice
- pasta
Carbohydrate digestion
- In mouth- salivary amylase
- stomach- salivary amylase inactivated by HCl
- small intestine- breakdown of disaccharides. pancreatic amylse break into monosaccharides, disaccharides and short chains of sugars called oligosaccharides
- **brush border= **microvilli. last site of digestion for carbs. break them into monosaccharides
- large intestine- fiber and other indigestible carbs are partially broken down by bacteria to form short fatty acids and gas
Absoption of carbohydrates
where it takes place and how. (type of diffusion)
carbs are broken down to glucose, fructose, galatose prior to absorption at bursh border
absorption of monosaccahrides takes place
- glucose and galactose
- active transport
-
Fructose
- facilitated diffusion
ALL are absorbed into CIRCULATORY SYSTEM/B
LOOD
Carbohydrate absorption
*indigestible carbs and their fate*
Their fate:
enter the large intestine
pull in water
soften stools
enhance peristalsis
some are broken down by bacteria–> short chain fatty acids then absorbed
rest is excreted as FECES
