Carbohydrates Flashcards
AMDR for CHO
45-65% of total energy
225-325kcal/2000kcal
RDA:
UL:
130g (only reflects amount needed for brain function)
no UL
Glycemic response
extent to which food raises blood sugar
Glycemic index
scale ranking CHO-containing foods by how much they raise blood sugar levels after consumption, high glycemic index=empty calories
Glycemic load
[glycemic index]x[g of CHO]
Glucose is the ___ energy source, preferred by ___ body parts
primary/most
Monosaccharides: chemical formula is ___
- ___: blood sugar, in every disaccharide
- ___: sweetest, in fruits, honey, and artificial sweetener
- ___: naturally present in dairy products
C6H12O6
glucose
fructose
galactose
Disaccharides: formed by ___ reactions which releases one ___ per bond formed, broken by ___.
- maltose = ___+___
- ___ = glucose+fructose
- ___ = galactose+___
condensation H2O/hydrolysis glucose/glucose sucrose lactose/glucose
Polysaccharides:
- ___: human storage form of glucose, highly ___
- starch: ___ storage form of ___, branches or unbranched, digestible
a. ___ starch: ___ digestion, acts like fibre - Fibre: ___ component of plants, resists ___, can be fermented to break down
a. ___ fibre: viscous, fermentable, often gummy, adds ___
b. ___fibre: tough, less fermentable, tough/stringy/gritty
glycogen/branched
plant/glucose
resistant/resists
structural/digestion
soluble/thickness
insoluble
Starch digestion pathway:
- mouth: amylase (in saliva) begins digestion
- stomach: inactivates enzymes and stops digestion
- small intestine/pancreas: pancreatic amylase is secreted to continue digestion, along with maltase, sucrace, and lactase
- monosaccharides are absorbed
Fibre digestion pathway:
- mouth: mechanical breakdown crushes it and saliva moistens it
- stomach: not digested, delays stomach emptying
- small intestine: not digested, delays absorption
- large intestine: bacterial enzymes turn fibre into short chain f.a. and gas, this holds water, regulates bowel activity, and draws things like cholesterol out of the body with it
___ and ___ enter intestinal cells via active transport while ___ used facilitated diffusion. In the ___ fructose and galactose are converted to glucose
glucose/galactose
fructose/liver
Lactose intolerance:
symptoms of intolerance are caused by the absence of lactase, somewhat genetic but can increase/develop with age, undigested lactose holds water in the lumen and lactic acid, methane, and H in the colon
What are the symptoms of lactose intolerance?
nausea, diarrhea, cramping, bloating, gas,
Dietary fibre AI:
UL:
DV:
38g/day (men), 25g/day (women)
no UL
25g/2000kcal
Actions of dietary fibre in the stomach, small intestine, and colon
stomach: delays emptying, prolongs full feeling
small intestine:not digested, slows absorption, gives better glycemic control, soluble binds bile acids (lowers fat/cholesterol absorption) and insoluble binds cations
colon: speeds up the process, attracts water (stops constipation), its fermentation lowers pH and protects the mucus layer, binds bile acids and toxins
Sorbitol
has a laxative effect
normal blood glucose level is ___mm/L
4-6
What are the functions of glucose in blood?
oxidized for free energy, converted to glycogen or fat to store energy, precursor for amino acids
As blood glucose rises and drops, the pancreas respond by releasing ___ (rising) or ___ (lowering)
insulin/glucagon
gluconeogenesis:
liver makes glucose from PRO if needed (when no CHO are consumed and glycogen is depleted)
ketosis:
body produces ketone to use an alternate fuel
Type 1 diabetes:
~10% of cases, high blood glucose, pancreas does not produce insulin at all, either autoimmune or viral
treatment: insulin, diet, exercise
Type 2 diabetes:
high blood glucose, pancreas either can’t produce or body can’t use insulin
Treatment: diet, exercise, sometimes insulin
