Ch. 4 - Carbohydrates Flashcards
carbohydrate provide _____ of kcal consumed by Americans
more than 1/2
how much energy per gram are found in carbohydrates?
4 kcal/g
unrefined or whole-grain products contain three key components, which are…
- endosperm (fiber, vitamin and minerals)
- bran layers
- germ (base of the kernel)
endosperm
- ____ portion
- made up of primarily ___, but also contains most of the kernel’s ____ along with some _________
- largest
2. starch, protein, vitamins/minerals
bran layers
- contain most of the ____ and are a good source of _______
- ____ layer
- fiber, vitamins and minerals
2. outermost
the germ
- located at the _____ of the kernel
- is the ____ where ____ occurs
- source of ___; rich in ____
- base
- embryo, sprouting
- oil, vitamin E
refined grains remove _____
bran and germ
refined grains may be enriched with _________; fortified with _____.
do NOT contain….
thiamin, riboflavin, niacin, iron; folate
Mg, Vit. E and some B Vitamins
types of simple carbohydrates
monosaccharide, disaccharide
complex carbohydrates are called ____
polysaccharides
three most common monosaccharides are…
- glucose
- fructose
- galactose
most important carbohydrate fuel for the body
monosaccharide
sweetest monosaccharide, same as glucose but structure is different
fructose
____ is the monosaccharide is part of milk sugar
galactose
plants most often convert ____ to ___ for energy. when humans eat plants, digestion converts ___ back to ____
glucose, starch; starch to glucose
sucrose is made by linking ________
glucose and fructose
_____ is the only sweetener that can be labeled “sugar”
sucrose
_______ (_____), is formed by linking two monosaccharides to form a dissaccharides
sucrose (table sugar)
types of disaccharide
maltose
sucrose
lactose
maltose is made from ____
two glucose molecules
lactose is made from _____
1 glucose and 1 galactose
rxn that breaks sugar molecules apart
hydrolysis reaction
rxn that links two sugar molecules together
dehydration (condensation) rxn
hydrolysis rxn needs ____
water in
dehyrdation rxn needs ____
water out
oligosaccharides contain short chains containing ___ monosaccharides
3-10
polysaccharides overview info
- long chains
- include glycogen (found in animals)
- include starch/fiber (found in plants)
dietary fiber (can/cannot) be digested and (is/is not) an important part of the digestive process
cannot; is
amylose are ______ chains/string
long, unbranched glucose
starches (amylopectin) with high amounts are ______ than high amylose
more quickly digested
amylopectin is _____
highly branched
why are highly branched chains easily to digest?
“more spots for enzymes to attach”
cellulose is a _____
long, straight, unbranched chain
two types of fiber
soluble (dissolves), insoluble (doesn’t dissolve)
fibers can be added to processed foods to ___ and ______
thicken, reduce fat and calories
good sources of soluble fiber
legumes, prunes, apricots, raisins, oats, apples, flaxseed
____ fiber promotes bowel movements
insoluble
good sources of insoluble fiber
wheat bran, broccoli, corn, whole-wheat bread, nuts/seeds
amylase timeline in carbohydrate digestion
amylase in mouth, stops in stomach, continues with pancreatic amylase
lactose intolerance occurs when…
there is not enough enzyme lactase in the SI to digest the milk sugar lactose
some other sources of lactose intolerance besides naturally occuring
microvilli damage, some medications, prolonged malnutrition/diarrhea
presence of fiber in the GI tract impacts
- GI functions
- intestinal microbiota
- amount of intestinal gas
- nutrient absorption (negative; Zn, Ca, Fe w/ insoluble)
how fiber impacts GI function
- ____ weight of material in the lumen of the intestine
- producing ______, promoting bowel health
- prevents ____
- reduces _____
- increases
- larger, softer stool
- constipation
- transit time
_____ = how quickly and how high blood glucose rises after carbohydrates are consumed
glycemic response
______ = a ranking of how a food affects the glycemic response
glycemic index
_____ = calculated by multiplying a food’s glycemic index by the amount of available carbohydrate in a serving of the food
glycemic load
why does fiber help promote larger, softer stool?
fiber attracts water
fiber ___ digestion/absorption
slows
glucose is metabolized through ______ to produce energy in the form of…
cellular respiration, ATP
cellular respiration is also called _____
aerobic metabolism
1 molecule of glucose yields ____ ATP molecules
38
when glucose is not present, processes such as ______ can help produce ATP
gluconeogenesis, ketogenesis
type of diabetes in which insulin is no longer made in the body
type I
type of diabetes in which insulin is present, but the cells do not respond (insulin resistance)
type II
type of diabetes which occurs during pregnancy
gestational diabetes
reactive hypoglycemia: ________ of insulin in response to carbohydrate intake; Tx includes ______
over secretion; frequent small meals high in protein
fasting hypoglycemia: ___ insulin secretion (related/not related) to food intake
abnormal, not related
carbohydrates in and of themselves (are/are not) “fattening”
are not
rationale for low-carb diet is that foods high in carbohydrates release insulin, promoting _______
insulin promotes energy stores, mostly from fat
with low carb diets, the body produces more ___
ketones
diets high in whole grains have been found to ______ of heart disease
reduce risk
_______ binds dietary cholesterol and reduces absorption
water-soluble fiber
types of bowel disorders
hemorrhoids
diverticulosis
diverticulitis
constipation
some ______ evidence exists that supports the high fiber diets lower incidence of colon cancer, but _____ do not support
epidemiological studies, intervention studies
