Fundamentals of Food and Nutrition; Composition, Safety and Nutrient Function- carbohydrates Flashcards
To Understand human nutritional needs
What are Carbohydrates made up of- basic formulas?
CH2O
What are monosaccharides?. Provide examples
Monosaccharides are the simplest sugars (most basic units), and are what provide the human body with energy.
They are the building block to complex carbohydrates.
Glucose, Fructose, Galactose
Extra points for xylose and ribose
What are disaccharides?. Provide examples and there components.
Disaccharides are two monosaccharides joined by glycosidic linkage.
The main 3:
Sucrose (table sugar), glucose + fructose.
Lactose (milk sugar), glucose + galactose.
Maltose (malt sugar), glucose + glucose.
Explain what a Glycosidic Bond in disaccharides?.
Glycosidic bonds are covalent chemical reactions that bond ring shaped sugar molecules to other molecules.
They form by a CONDENSATION reaction between two monosaccharides; H2O is released.
What are oligosaccharides?
Oligosaccharides are carbohydrates that contain two or more monosaccharides (2-20)
Non-digestible oligosccahrides examples and there benefits
Galactooligosccharides and fructooligosaccharides.
-Stimulate growth of Bifidobacteria thus modifying the composition of colonic microbiota.
-A legitimate dietary fiber as they help with stool bulking and reduce the number of bacteria with pathogenic effect in the gut.
Non-digestible oligosaccharide properties?
Non-digestible because of there osidic bonds, they resist hydrolysis by salivary and intestinal enzymes.
In the colon they are fermented by anaerobic bacteria. They share similar effects to soluble dietary fibre.
What is Glucan?
Glucan is a polymer of glucose; a high molecular compound- an oligosaccharide.
They differ in ANOMERIC CONFIGURATIONS and GLYCOSIDIC LINKAGES
What is Glucans Function?
Glucan plays a role in the cell wall structure of plants.
In the body they are used as an energy sources for metabolism.
Extra points for, control cell differentiation, regulate cell growth, control viral infections and immune responses.
What is Beta Glucan? and a common example
B-glucan is a soluble fiber, available from oat and barley grains (Dietary fiber)
-Have a functional bioactive property
-Studies have shown they have a beneficial role on insulin resistance, hypertension and obesity
Cellulose, found in algae and plants. Has a branched molecular structure.
What is an Alpha glucan?. 3 common Examples
A-glucans are viewed as polymers with an energy storage function in the cell (starch).
Glycogen- storage unit found in animals. Has a linear molecular structure
Starch (Amylose, Amylopectin). Storage unity of plants. Amylose is a linear chain, Amylose pectin has a branched formation.
What are polysaccharides? and provide examples.
Polysaccharides and carbohydrate molecules that consist of a number of different sugar molecules bonded together.
Starch, cellulose, glycogen, amylose and amylopectin.
The digestion and absorption of Carbohydrates.
the body contains digestive enzymes which breakdown polysaccharides into monosaccharides; the final product of carbohydrate digestion.
Monosaccharides are absorbed into the small intestine and absorbed into the liver where fructose and galactose are converted into glucoside which is then used for energy.
Metabolism, explain what it is?
Excess glucose, beyond what the body needs is stored and glycogen in the liver and muscles. If blood glucose levels fall to low glycogen is broken into glucose.
The body can only store a small amount of glycogen, thus the body needs a constant supply of carbohydrates.
Many cells use fat for energy however brain, nerve and red-blooded cells cannot.
What are sugar alcohols? And there characteristics
Polyols (sugar alcohols) are classes as carbohydrates and naturally occur in many fruits and vegetables, but are widely consumed in sugar free or reduced sugar products.
polyols have lower nutritional value then sugar due to there slower and incomplete absorption from the intestines.they are fermented in intercessional flora where that act as a prebiotic and anti carrageen similar to fibre which helps with healthy intestinal function.
They have hight stability in high temperatures and can sustain acidic or alkaline conditions, therefore don’t partake in the Maillard reaction.
