Carbohydrates Flashcards
What characterizes complex carbohydrates?
Not sweet tasting, insoluble in water, don’t form crystals
Mention some monosaccharides
Glucose, fructose, galactose
Sweet tasting, water soluble, crystalline structure
Mention some disaccharides
Sucrose, maltose, lactose
How are Glycemic Index values calculated?
GI = ( test meal / standard meal ) *100%
Standard meal (reference) is pure glucose, that has a set value of GI=100
(Tal værdien af test meal er arealet under kurven for blood-glucose response. Det er altså en værdi for påvirkningen på blodsukkeret)
What is the definition of glycemic carbohydrate?
Can be digested by carbohydrate-degrading digestive enzymes and be absorbed in the small intestine.
results in an increase of the blood glucose
What is the definition on non-glycemic carbohydrates?
- Resistant to digestive carbohydrate degrading enzymes
- Do NOT increase blood glucose concentration
- Fermented in the large intestine by microorganism
What is the definition of Glycemic index (GI)?
The extent to which it raises the blood glucose concentration compared with an equivalent amount of a reference carbohydrate (hvidt brød)
Hvor meget energi er der i 1 gram karbohydrat?
4 kcal (16 kilojoule) pr gram karbohydrat
Hvilke 3 monomere er de eneste vi kan optage?
Glukose, fruktose og galaktose
Mention two types of starches
Amylose, amylopectin (polysaccharide).
Both are glucose polymers
Den største carbohydrate til energi opbevaring i planter
How are the glucose molecules in glycogen bound?
alfa-1,4 bounds in straight polymer and alfa-1,6 in to the branched polymers
Why does cooking and processing food elevate the GI of the carbohydrate?
- When cooked the starch molecules absorb water and become disposed to digestive enzymes
- Blending/grinding also breaks down and makes the starches more available
What happens to fiber in the large intestine?
- If water-soluble, it is fermented into SCFA (short chain fatty acids).
- If not water soluble, fermentation is limited
What happens to fiber in the small intestine?
Dietary fiber are resistant to digestion and absorption in the small intestine
What is the definition of glycemic load (GL)
- Is a value for how much your blood sugar will rise at a given portion of the food
- Low → low raise in blood sugar
- High → high raise in blood sugar
How to calculate GL?
GL = (grams of carbohydrates x GI (glycemic index))/100
Hvilke makromolekyler bidrager kulhydrater til at der kan syntetiseres i kroppen?
- Syntese af ikke-essentielle aminosyrer
- Syntese af ribose (til RNA og DNA og elektron carriers)
- Glykolipider
- Glycoproteiner
What does maltose consist of?
Two molecules of glucose
What does lactose consist of?
galactose og glucose
What does sucrose consist of?
Glucose and fructose
What does a high GI (glycemic index) mean?
That it is fast digested, absorbed and metabolised, and gives a significant raise in blood sugar
What does a low GI (glycemic index) mean?
That it is slowly digested, absorbed and metabolised, and gives a lower raise in blood sugar
What are the primary function of carbohydrates?
Energy production: glycolysis or fermentation
Energy storage: starch(plant) and glycogen (animal)
Structural support: cellulose (plant) and chitin (exoskeleton)
What are glycosaminoglycans?
Unbranched polysaccharides of repeating disaccharide units. One component is an amino sugar and the other is normally glucoronic acid.
(amino sugar = glucosamine or galactosamine)
Where are the different carbohydrates digested- and taken up
Et godt huske billede
Where do you typically find glycolipids?
In cell membranes, especially in the nervous system
What is the purpose of PPP (pentose phosphate pathway)?
Conversion of glucose into ribose-5-phosphate
used to make DNA, RNA and in elektron transport
What is the purpose of Glycolysis?
Conversion of monosaccaride (glucose) into pyruvate
Aerobic = convert pyruvate into ATP
Anaerobic = convert pyruvate into lactate
What is the purpose of the cori cycle?
Conversion of lactate from anaerobic muscle work into glucose in the liver
What is the purpose of gluconeogenesis?
Conversion of non-carbohydrate (pyruvate) into monosaccharide (glucose)
Which pathways are a part of glucose homoeostasis?
Glycogenesis: convert glucose into glycogen
Glycogenolysis: convert glycogen into glucose
What hormone stimulates glycogenolysis, gluconeogenesis and lipolysis?
(Nedbryder glucogen til glucose, omdanner pyruvat til glucose, nedbryder fedt)
Adrenaline (epinephrine)
During starved state or when in need of ekstra energy
What stimulate gluconeogenesis and lipolysis as well as inhibit glucose uptake?
(result in elevated blood glucose level)
Cortisol and growth hormone
