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Simplifed introduction into Carbohydrates which includes carbohydrates testing and digestion
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CarbohydratesDone by: Valerie, Jilian, and Catherine
Carbohydrates
Hydrates of carbon
Chemical composition
of (CH2O)n
Primary source of
energy for our bodies
Good source of fiber
and vitamins
Carbohydrates
Rich in phytonutrients
Participate in many
essential body
functions
Two types - simple and
complex
Simple Carbohydrates
Fruits, milk, and
vegetables
Simple sugars found in
refined sugar foods
e.g. sweets, cakes
Monosaccharides &
disaccharides
Monosaccharides
Simplest carbohydrate
Basic sugar unit
Three variations: glucose, fructose, galactose
Monosaccharides
Glucose Fructose Galactose
Mild sweet
flavour
Sweetest
sugar
Hardly tastes
sweet
Known as
"blood sugar"
Found in fruits and
honey
Rarely found
naturally alone
Essential energy
source
Added to soft
drinks, cereals
Disaccharides
Made up of two monosaccharides
Formed through condensation
Taken apart via electrolysis
Three types: sucrose, lactose, maltose
Disaccharides
Sucrose Lactose Maltose
Fructose and
glucose
Glucose and
galactose2 Glucose units
Found in table
sugarFound in milk Not abundant
Produced when
starch breaks
down
Complex Carbohydrates
Provide vitamins,
minerals, and fiber
Found in breads,
pasta, and starchy
vegetables
Polysaccharides
Polysaccharides
Chains of monosaccharides
Glycogen and starch
built purely on glucose
Fiber
variety of monosaccharides and carbohydrate
derivatives
Glycogen
Limited in meat and not found in plants
Not an essential source of carbohydrates
Glucose is always stored as glycogen
easy release of energy in long chains
Starch
Found in plants and stored in plant cells
Created through photosynthesis
Body hydrolyzes plant starch into glucose
Fiber
Structural parts of plants
Fibers are not broken down during digestive
process
Two types - soluble and insoluble
Fiber
Soluble Insoluble
Easily digested by
bacteria in colonPromotes bowel movement
Associated with
protection against heart
disease and diabetes
Alleviates constipation
Found in legumes and fruitsFound in grains and
vegetables
Testing for
Carbohydrates
Testing for
CarbohydratesBenedict's Test for
Reducing Sugars
Iodine Test for Starch
Benedict's Test
Used to test for presence of reducing sugars
all monosaccharides
disaccharides: lactose and maltose
Requires use of Benedict's Reagent
prepared from CuSO4, NaOH, tartaric acid
Benedict's Test
1. Dissolve food sample in water
2. Add small amount of Benedict's Reagent
3. Heat in water bath from 4 - 10 minutes
4. Positive test indicated by a brick red solution
How can we test for
Sucrose?
Testing for Sucrose
Sucrose is a non-reactive substance
does not react with Benedict's Reagent
Break down with dilute Hydrochloric Acid before
testing
broken down into fructose and glucose
Iodine Test
Used to test for starch
Requires use of Iodine
solution
dissolve iodine in
potassium iodide
Iodine Test
1. Add Iodine solution directly to food sample
2. A dark blue-black colour indicates presence of
starch
Carbohydrate Digestion
Carbohydrate Digestion
Break down carbohydrate into glucose
able to be absorbed and used by body
Starch - extensive breakdown
Disaccharides - broken down once
Monosaccharides - need not be broken down
Carbohydrate Digestion
Occurs throughout digestive system
Begins in mouth
chewing releases saliva
starch broken down by enzymes into
polysaccharides and maltose
Digestion in the
Stomach
No enzymes available for starch breakdown
Acid does minor breakdown
Fibers provide feeling of "fullness"
Digestion in the
Small Intestine
Primary site of carbohydrate digestion
Pancreatic enzyme reduces carbohydrates into
glucose chains or disaccharides
Specific enzymes are present to fully reduce
disaccharides
Digestion in the
Large Intestine
1 to 4 hours for sugars and starches to be fully
digested
Only fibers remain
retain water to soften stool
In Summary
Carbohydrates are
important for daily
living
Digestion is a complex
and thorough process
Can be tested using
various methods
Thank You!