carbohydrates Flashcards
Describe difference between Glycemic index and glycemic load
Glycemic index rates foods according to their effect on BGL and Glycemic load is the amount of carbs in a specific serving of food
What is the enzyme that breaks down starch in the mouth
Amylase
Where does most digestion of starch happen
small bowel.
what enzymes break down starch in the small intestine
pancreatic enzymes - pancreatic amylase
what are the function of carbs
immediate source of fuel for cells,
metabolised by gut micro organisms to produce SHORT CHAIN Fatty acids and vitamins
Can bind with protein & lipids = glycoprotein and glycolipids
Oligosaccharide in breast milk have immune stimulating effect
List 3 monosaccharides - single sugars
Glucose
Fructose
Galactose
List the 3 disaccharides (pairs of monosaccharides )
Sucrose - Fructose +glucose
Maltose - Glucose +Glucose
Lactose - Glucose + Galactose
List the complex carbs
Starch, fibre and glycogen
Oligosaccharides (3-10 monosaccharide molecules)
Polysaccharides (long chain of glucose)
which atoms make up carbohydrates
carbon, hydrogen water (CHO)
What are the sources of CHO
- Grains - breas, cereals, corn
- Legumes - lentils, beans, peas
- Fruit and veg
- Dairy foods, mainly milk & yogurt
- Processed foods - sweets & hidden
what is the main CHO in processed foods`
sucrose
describe the digestion of Carbs
`1. Mouth - malaise breaks starch into shorter polypeptides
2. Stomach - amalyase is deactivated - no further digestion occurs
3. Small intestine - most digestion occurs here - pancreatic amylase breaks down starch into monosaccharides , disaccarhides and oligosaccharides .
describe the regulation of Glucose
after a meal BSL rises.
Insulin is released from pancreas stimulating glucose uptake by liver, fat and muscles
it is turned into glycogen in liver and muscles - glucose in fat storing cells.
after a meal BSL drops, glycogen is released from liver - pancreas stimulates breakdown and release of glycogen into glucose
what are the issues with over consumption of CHO
Weight gain, increased risk of type 2 diabetes and gut issues
what are the causes of CHO deficiency (gluconeogenesis
Low carb diet or keto diet - reduced carbs forces body to use fats and protein as fuel
Prolonged fasting or starvation - depletes glycogen stores
Intense exercise without sufficient carbs leading to protein breakdown
Uncontrolled diabetes - impaired glucose uptake forces body to use alternative energy sources
malnutrition or severe calorie restriction
what are the tests used to diagnose Diabetes
Fasting Blood Glucose (FBG)
oral Glucose tolerance test (ogtt)
Hemoglobin A1c (HbA1c)
Random blood glucose test
what are oligosaccharides
3 - 10 monosaccharide units linked by glycosidic bonds
Classified between simple and complex carbs in terms of structure an digestion
What are Polysaccharides
Complex carbs composed of long chains of Monosaccharide units linked by glycosidic bonds. Contain more than 10 molecules . Serve as energy storage, structural component s or functional biomolecules
What is Glycogen
A Polysaccharide used as primary storage from of glucose in animals /humans.
made of highly branched chains of glucose molecules
stored in liver and muscles
what is Starch
Complex carb (Polysaccharides) made of long chains of glucose linked together. The primary energy storage carb in plants and a major source of dietary carbohydrates in humans
describe Non starch Polysaccharides dietary fibre (NSP)
Not digested by enzymes - some are digested by gut bacteria.
absorbs water, toxins and other substances
Adds bulk to stools
Acts as prebiotic
Examples of Non starch polysaccharids
pectins (citrus peel/apples)
gums - seaweed
whole grains, vegetables, legumes fruit
What is resistant starch
Not digested
Ferments in large bowel and changes to short chain fatty acids that feed bacteria in gut.
Fibre like effect - classed as fibre
no digestion in Small bowel
Examples of resistant starch
Green bananas , cooked and cooled rice, cooked and cooled potato
