Unit 2.1 Flashcards
What are some reasons a person eats carbs
To lose weight
To bulk up with muscle
Carbs are a primary or only source of energy for what cells?
CNS
RBC
Muscles for vigorous physical activity
Glucose, fructose, and galactose are examples of:
Monosaccharides
Major sugar in foods and in the body
From starch, sucrose and lactose
Glucose
Fruit sugar
From sucrose, honey, fruits and high-fructose corn syrup
Fructose
From lactose
Only dietary carb exclusively for animal sources
Galactose
Maltose, sucrose and lactose are examples of:
Disaccharides
Types of simple carbohydrates
Monosaccharides
Disaccharides
Oligosaccharides
Maltose source:
From ____ break down
Linkage:
Molasses
Starch
Alpha-1,4 glycosidic linkage
Sucrose is what type of sugar?
Sucrose
What type of linkage is sucrose?
Alpha-1,2 glycosidic linkage
Lactose is what kind of sugar?
Milk
The only animal dietary carbohydrate
Linkage type for lactose
Beta-1,4 glycosidic linkage
Types of oligosaccharides
Maltotriose
Raffinose
Stachyose
Maltotriose is from _____ degradation
Starch
Linkage type for maltotriose
2 alpha-glycosidic linkages
Raffinose is found from ____.
Beans (legumes)
Linkages for raffinose
One beta-1,6 and one alpha-1,2 glycosidic linkage
Gal-Glc-Fru
Stachyose is a simple carbohydrate from
Beans
Linkages of stachyose
Two beta-1,6 and one alpha-1,2 glycosidic linkage
Gal-gal-glc-fru
What is cellulase?
Enzymatic activity capable of breaking beta glycosidic linkages
What cells have cellulase activity?
Only microbial cells
Cellulase is high in the gut of:
Ruminants
Termites
Ants
Fungus
What are digestible polysaccharides?
Starch (whole grains, pastas, bread, legumes, potatoes)
Glycogen (non dietary— liver and muscle)
What are indigestible polysaccharides? Examples?
Insoluble fiber
- cellulose, hemicellulose (plant cell wall)
Soluble fiber
- Pectin (Flesh of fruits)
- mucilages (psyllium husk, flaxseeds)
- Gums and beta glucans (oats, legumes, barley)
- Algal polysaccharides (algae and seaweeds)
What type of starch?
Linear polymer, alpha-1,4 linkages only
About 20% of typical starch
Amylose
What type of starch?
Branches polymer, alpha 1,4 and alpha-1,6 linkages (about ever 25 glucose)
About 80% of typical starch
Amylopectin
Typical starch is found where?
In white potatoes
Wheat
Corn
Rice
Modified starch is more _______ in to increase:
Branches
Gelling properties
Glycogen is storage of ______ in animals and bacteria
Glucose
Glycogen is structurally similar to ______, but is more _____.
Amylopectin
Branches
Linkages of glycogen
Alpha-1,4 and alpha-1,6
Branches (alpha 1,6) about every 10 glucose
Glycogen is more ______ than amylopectin
Soluble
Glycogen can do what very rapidly? (3)
Can be synthesized
Be degraded
Raise blood
Glycogen is stored in the _____ for blood glucose
And in the ______ for muscle energy
Liver
Muscle
Glycogen (IS/IS NOT) a dietary carbohydrate
Is not
Monosaccharides in fibers are linked by:
Beta-glycosidic linkages
What is a non-carbohydrate fiber? Where can it be found?
Lignin
Woody parts of plants (bark)
Polyphenols
Flaxseeds, sesame seeds, whole grains, legumes, fruits and veggies
Lignin builds to ___ _____ and decreases:
Bile acids
Serum cholesterol levels
What are examples of carbohydrate fiber
Cellulose
Hemicellulose
Pectin
Gum
Mucilage
Name examples of insoluble/non-fermentable fiber
Cellulose
Hemicellulose
Lignin
(Not fermented by bacteria in the colon)
Examples of soluble / viscous / fermentable fiber
Gum
Pectin
Mucilage
Fruit
Vegetable
Rice bran
Psyllium seed
Prebiotic are are type of:
They stimulate:
Functional fiber
Growth or activity of beneficial bacteria in the large intestine
Review table in slide 17. Type that up later
Slide 17
Carbohydrates in milk
Lactose
Processed grains are relatively (HIGH/LOW) in fiber
Low
2 categories of sweeteners
How do they provide energy?
Nutritive sweeteners
-can be oxidized to yield energy
Alternative sweeteners
-provide no energy or very little
High-fructose corn syrup is mixed with:
Acid and enzymes
Benefit of high-fructose corn syrup
It is cheaper than sucrose
Sorbitol and xylitol are examples of what?
Sugar alcohols
Excess consumption of sugar alcohols may have what effect?
A laxative effect
What is the benefit of sugar alcohols?
They do not promote tooth decay (can be seen in sugarless gum)
ADI for alternative sweeteners
mg per kg of body weight per day (that’s a mouthful)
How many calories per gram in aspartame?
4 ca/g, but only a trace amounts is needed to sweeten foods
Aspartame is not recommended for people with what?
Phenylketonuria (PKU)
ADI for aspartame:
50– or about 14 cans of diet soft drink or about 80 packets of sweetener
Steviol is a:
Glycoside
Substrate, products and linkages of…
Alpha-amylase (saliva and pancreas)
Sub- starch
Products: Limit dextrin, increase maltose, maltotriose, isomaltose
Linkages: Alpha-1,4
Substrate, products and linkages of…
Alpha-dextrinase
Sub- limit dextrins
Products: Malto-oligosaccharides
Linkages: alpha-1,6
Substrate, products and linkages of…
Maltase
Substrate: Maltose
Products: 2 glucoses
Linkages: alpha-1,4
Substrate, products and linkages of…
Glucoamylase
Substrate: maltotriose
Products: 3 glucoses
Linkages: alpha-1,4
Substrate, products and linkages of…
Sucrose-isomaltase bifunctional domain isomaltase
Substrate: isomaltose
Products: 2 glucose’s
Linkages: alpha-1,6
