Carbohydrates Flashcards
Glucose is insulin
dependent Via GLUT 4 their is also independent uptake by the liver
undergoes glycogenesis and glycoslysis depening on demand
contributes blood sugar levels
Fructose is not
insulin dependent
sweetest
excess fatty liver
galactose
converted glucose in liver
Fate of monosaccharides
Transported to liver and other organs via blood circulation • Glucose and other monosaccharides enter cells via glucose transporters (GLUTs) (type of facilitated absorption) • Liver converts fructose and galactose to intermediates of glycolysis (see diagrams earlier) for energy production • Glycogenesis takes place under the influence of insulin in the fed state • Excess glucose availability can result in lipogenesis via acetyl CoA under excess and high insulin conditions
digestibility AMylsoe
amylose slower to digest than amylopectin as amylopectin branched 4
blood glucose regulation
elavated - pancreas insulin - glucose transported into cells, conversion of glucose into glycogen and normilisation
low blood glucose- pancrease release glucogon increased gluconeogenesis , breakdwon of glycogen to glucose normal
GI
• The GI ranks carbohydrate-containing foods based on their effect on blood sugar levels over
two hours post-ingestion
• The GI compares foods servings that have gram-for-gram the same amount of carbohydrates
(50 grams)
• Carbohydrate-containing foods are rated against glucose, which has a GI score of 100
High GI foods • Carbohydrate foods that are digested quickly, resulting in glucose absorbed rapidly, have the highest glycaemic indexes (GI more than 70). The “blood glucose response” is fast with high peaks. Low GI foods • Carbohydrates foods that are digested slowly, result in gradual glucose absorption and gradual moderate rise in BGL. They have low glycaemic indexes (GI less than 55). The “blood glucose response” is slower and flatter. (sometimes white bread is also used as a reference food)
FACTORS AFFECTING THE GI OF A FOOD OR A MEAL
• Amylose to amylopectin ratio
• Degree of processing. E.g. whole meal flour vs refined flour; micronised
starch versus whole grain
• Fat content of food /meal (e.g. lactose in whole fat milk versus low fat
milk)
• Acidity ( affects amylase activity and gastric emptying)
• Sugar content + type of sugar
• Other macronutrient contained in the food /meal
• Ripeness of fruit. Why?
• Fiber content. Why?
GL
Based on the amount of carbohydrate (CHO) in the food serve being consumed • Multiply the amount of CHO by the GI value of the food and divide by 100 • Rate the GL according to the reference • Why would it be healthier to consume low GL foods?
soluble insoluble fibre
Soluble fiber Oatmeal, oatbran, nuts and seeds, legumes, apples, pears, strawberries, blueberries Insoluble fiber Whole wheat breads, barley, brown rice, bulgur, whole-grain breakfast cereals, breads, and pasta, seeds, carrots, cucumbers, celery, tomatoes
functions of fibre
1- Promoting bowel health
By increasing faecal bulk and laxation preventing diverticulosis/diverticulitis
2- Reducing obesity and weight gain risk:
By assisting in appetite control because it slows down gastric emptying, thus increased
satiation and less risk of overeating
3- Assisting in blood glucose control
- By slowing down gastric emptying, therefore slowing down CHO digestion and glucose
absorption, and rise of BGL.
- By making the digestible CHO less easily accessible to enzymes: outcome?
4- Reducing plasma cholesterol (CVD benefit?)
Promotes binding and excretion of dietary cholesterol and bile, and thus prevents
“reabsorption” of cholesterol (this will be discussed when studying lipid in week 5
5- Promoting gut and overall health
Via gut bacteria fermentation. Promotes growth and diversity of bacterial species and
produces short chain fatty acids (SCFA): acetate, butyrate, propionate => protective effects
on colonic cells (prevention of colon cancer), and a variety of health benefits for the host
Tom’s EER is 13450 kJoules. What is the upper amount of the AMDR for carbohydrate in grams you recommend?
514
Examples of digestible polysaccharides are
Amylose, amylopectin and glycogen
After a late night, you overslept this morning and woke up late for class. In a rush to leave the house, you drink a chocolate flavoured maltose sweetened drink. Rapidly, your blood glucose levels [A]. This prompts your pancreas to release [B] and promotes [C] in the liver and [D]
After a late night, you overslept this morning and woke up late for class. In a rush to leave the house, you drink a chocolate flavoured maltose sweetened drink. Rapidly, your blood glucose levels Correct Increase. This prompts your pancreas to release Correct Insulin and promotes Correct Glycogenesis in the liver and Correct Muscle.
Undigested disaccharides:
Are the reason for excessive gas production resulting from bacterial fermentation
What are the functions of soluble fiber?
- Water-holding capacity to increase gut transit time
- Substrate for short-chain fatty acids via bacterial fermentation
- Reduce the impact of carbohydrate foods on glycemic response
- Bind amino acids, increasing their excretion
Correct5.
2 and 3 are correct
- Non of these are correct about water soluble fiber
\
- Substrate for short-chain fatty acids via bacterial fermentation
- Reduce the impact of carbohydrate foods on glycemic response
Correct5.
2 and 3 are correct
dri fibre
their is none
low fibre may lead to
1.
Increased cholesterol excretion
- Inadequate calorie absorption
- Poor hydration
- Increased calorie absorption
- Diverticulae
Diverticulae
- It contains more alpha bonds which make it sweeter
- It is made of 100% fructose
- It may contain more minerals and vitamins because of the processing steps
- It may contain more of less fructose depending on the type manufactured
- It is digested more quickly because of the enzymatic treatment, making it sweeter
4.
It may contain more of less fructose depending on the type manufactured
definitions Amylose Prebiotic Starch Amylopectin Glycogen
Amylose
Correct E.
Polysaccharides in chain formation]
Prebiotic
Correct A.
Structures with beta-glycosidic bonds between saccharides
Starch
Correct C.
Polysaccharide storage in plants
Amylopectin
Polysaccharides in branched formation
Glycogen
Correct D.
Polysaccharide storage in animals
\
You go to your third class of the day, but because you haven’t had any lunch, your blood sugar level is [A]. You tend to doze off, but awake to your classmate poking you in the arm as you realise the lecturer is asking you to answer a question. With your heart racing, your body now releases adrenaline in addition to [B]. This increases [C] breakdown in the liver and raises your blood sugar.
low
glucagon
glycogen
.
A good example of functional fibre intake in the diet is:
Adding psyllium husk to a noodle and beef stew
- Choosing to have a pear for morning tea instead of biscuits
- Having oats for breakfast
- Choosing brown rice sushi instead of the standard white rice option
- Making sausages with wholemeal bread crumbs and mince
Adding psyllium husk to a noodle and beef stew
Insulin impacts on GIT glucose absorption by [A]
Insulin impacts on GIT glucose absorption by Correct Signalling GLUT 2 removal from the enterocyte at the apical surface
Which of the following is classified as a non-nutritive sweetener?
Aspartame
- Maltose
- Mannitol
- Honey
- Sorbitol
Aspartame
0 out of 1 points
After morning class, with your stomach growling, you stagger to the cafeteria and devour a large pasta dish for lunch. Following this meal, your blood sugar rises and the pancreas releases [A] in an attempt to shuttle [B] into your cells via [C]
After morning class, with your stomach growling, you stagger to the cafeteria and devour a large pasta dish for lunch. Following this meal, your blood sugar rises and the pancreas releases Correct Insulin in an attempt to shuttle Correct Glucose into your cells via Correct GLUT4.
0 out of 1 points
Soluble dietary fibres are not digested in the small intestine but fermented in the large intestine by digestive enzymes.
false
