Module 2 - Carbohydrates Flashcards
sucrose
glucose + fructose
lactose
glucose + galactose
hexose monosaccharides
monosaccharides with 6 carbons including glucose, fructose, and galactose; needed to build more complex carbohydrates
pentose monosaccharides
needed to build DNA or RNA
t/f? Most research shows that ribose supplementation in humans improves athletic performance.
False
oligosaccharides
made up of 3-9 monosaccharides
polysaccharides
made up of more than 9 monosaccharides
ex. starch
Simple Carbohydrates
monosaccharides, disaccharides, sugar alcohols,
Sugar alcohols
fewer calories than glucose and often used as sugar replacers in sugar free foods which reduces the number of calories but does not make it zero
most commonly consumed carbohydrates:
glucose, fructose, lactose, sucrose, maltose, starch and fibre
galactose
monosaccharide that is converted to glucose by the liver
tagatose
fructose isomer created in lab which is 90% sweeter and has fewer calories than glucose therefore it can be used in diabetic candy and sugar free foods.
disaccharide formation and digestion reactions:
condensation reaction forms disaccharides out of two monosaccharides, hydrolysis reaction separates disaccharides into two monosaccharides
maltose
disaccharide produced when starch breaks down
glycogen
storage form of glucose found in liver and muscles
amylose
polysaccharide; a plant starch made of glucose molecules
cellulose
polysaccharide; a form of dietary fibre
simple sugar:
monosaccharides
mouth
start of digestion; mechanical and chemical digestion
amylase
salivary amylase breaks down amylose which is a polysaccharide plant starch
gastric emptying
moving food from stomach to small intestine; delayed by fibre creating a feeling of satiety
small intestine:
duodenum, jejunum and ileum; 10-20ft long; 1in diameter; villi and microvilli contribute to large surface area;
villi
contain an artery, vein, and lymphatic capillary,
collection of microvilli
brush border
chemical digestion in small intestine
pancreatic amylase and brush border enzymes
brush border enzymes
maltase, sucrase, lactase
lactose intolerance
condition where individuals can’t digest disaccharide lactose due to hypolactasia which is a reduction in lactase activity.
what milk is recommended for people with lactose intolerance?
goats milk because it has a lower concentration of lactose mass/volume
what % of Canadians self report lactose intolerance
?
16%
what are symptoms of lactose intolerance?
diarrhea, abdominal bloating and pain, flatulence, and nausea
primary vs secondary lactose intolerance?
primary: changes in expression of the LCT gene leading to a reduction in lactase after age 2-3
secondary: congenital lactase deficiency where a newborn does not produce lactase at birth
lactase persistent:
people who can consume large quantities of dairy containing lactose with no symptoms
3 genotypes associated with lactose tolerance:
homozygous persistent: no symptoms
heterozygous: less lactase produced resulting in symptoms if there is intestinal injury or disturbance
homozygous non-persistent: least amount of lactase, likely to present symptoms
where is lactase persistence most and least common globally?
most: northwestern Europe
least: africa, caribbean, Mexico, asia
what might help with lactose intolerance aside from enzyme supplements or lactose free dairy?
consuming full fat milk which causes a delay in gastric emptying.
where are carbohydrates absorbed
once broken down in bush border, absorbed in upper small intestine
how are carbs absorbed?
fructose: facilitated diffusion
glucose and galactose: active transport
what regulates phase of glucose? blood sugar
insulin, glucagon, epinephrine
Which organ is responsible for converting galactose to glucose?
liver
what are the different categories for recommended carb intake?
total carbohydrate intake
free sugar intake
fibre intake
grain product intake
what is glucose used for in the body?
glycolysis to provide energy for our cells.
what is a whole grain made up of?
endosperm
bran
germ
what does grain refining do?
removes bran and germ
what is missing from refined grains in terms of nutrients
fibre vitamin b minerals antioxidants vitamin e
what does research indicate about people who consume whole grains daily
lower body mass index BMI, cholesterol, blood sugar,
what is the RDA for carbs?
130 grams of carbs per day
define ketosis:
increase in kept acid production by the liver which can provide alternate fuel to the brain when blood glucose levels are low
AMDR for carbs?
45-65% of total calories consumed.
‘bliss point’. What does this term refer to?
The perfect level of sweetness of a product
One of the reasons that added sucrose is detrimental to our health is that the monosaccharide (fill in blank) is converted to (fill in blank) in the liver.
fructose, fat
