Transcript Glucose - davis.k12.ut.us

Carbohydrates
Can you live without sugar?
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Soda/Punch
Cookies
Candy
Chocolate
Desserts
Sugary Cereals
Ice cream
CARBOHYDRATES
1. 60% of our
food should
come from
carbohydrates.
Carbs
Protein
Fats
2. Carbohydrates are grains, fruits,
vegetables, legumes and sugar.
Carbohydrates
 glucose provides energy for the brain and ½
of energy for muscles and tissues
 glycogen is stored glucose
 glucose is immediate energy
 glycogen is reserve energy
CARBOHYDRATES
3. Carbohydrates
give the body
energy. They are
the best source of
fuel for the body.
Carbohydrates
also help to digest
protein and fat.
 2. Carbohydrates also play a vital part of
the metabolism and oxidation of protein
 Carbs help feed the brain and nervous
system and helps keep the body lean.
CARBOHYDRATES
4. If we eat more
carbohydrates
than are needed
for energy, the
extra is stored in
the liver or in the
tissues as fat.
Carbohydrates
 5. all plant food
 Milk (LACTOSE)
 carbohydrates are not equal
– simple carbohydrates
– complex carbohydrates
Simple Carbohydrates
6. Simple carbohydrates are quick
energy sources. They come from
sugar. They do not usually supply
any other nutrients or fiber.
Simple Carbohydrates
 sugars
– monosaccharides – single sugars
– disaccharides – 2 monosaccharides
Simple Carbs
 monosaccharides
– all are 6 carbon hexes
 6 carbons
 12 hydrogens
 6 oxygens
 arrangement differs
–accounts for varying
sweetness
– glucose, fructose,
galactose
Glucose
 mild sweet flavor
 10. known as blood
sugar
 essential energy source
 found in every
disaccharide and
polysaccharide
Fructose
 sweetest sugar
 found in fruits and honey
 added to soft drinks,
cereals, deserts
Galactose
 hardly tastes sweet
 rarely found
naturally as a single
sugar
Disaccharides
 pairs of the monosaccharides
– glucose is always present
– 2nd of the pair could be fructose, galactose
or another glucose
– taken apart by hydrolysis
– put together by condensation
– hydrolysis and condensation occur with all
energy nutrients
– maltose, sucrose, lactose
Maltose
 2 glucose units
 produced when starch breaks down
 not abundant
Sucrose
 fructose and
glucose
 tastes sweet
– fruit, vegetables,
grains
 table sugar is
refined sugarcane
and sugar beets
 brown, white,
powdered
Lactose
 glucose and galactose
 main carbohydrate in
milk
– known as milk sugar
Simple Sugars
7. Glucose or blood sugar is the
basic source of energy for all
living things.
8. Sucrose or table sugar is made
from sugar beets or sugar cane.
9. Fructose is sugar found in fruit,
honey and vegetables.
11. Maltose is grain starch broken
down into sugar.
12. Lactose is milk sugar.
Complex Carbohydrates
 starches and fibers
 polysaccharides
– chains of monosaccharides
Complex
Carbohydrates
13. Complex carbohydrates
supply longer lasting
energy, as well as other
nutrients and fiber that the
body needs. They are a
better choice.
Condensation
 making a disaccharide
– chemical reaction linking 2
monosaccharides
Hydrolysis
 breaking a disaccharide
– water molecule splits
– occurs during digestion
Complex Carbohydrates
 polysaccharides
– 1.glycogen and 2.starch
 built entirely of glucose
– 3.fiber
 variety of monosaccharides and other
carbohydrate derivatives
Glycogen
 limited in meat and not found in plants
– not an important dietary source of
carbohydrate
 BUT
– all glucose is stored as glycogen
– long chains allow for
hydrolysis and release
of energy
Starches
 stored in plant cells
 body hydrolyzes plant starch to glucose
STARCHES
 14. Starch in the body breaks down simple
sugars. The body has to break down all
sugar and starch into glucose to use it.
 15. All starchy foods are plant foods, seeds
are the richest source; 70% of their weight is
starch
Fiber
 structural parts of plants
– found in all plant derived food
 bonds of fibers cannot be broken down
during the digestive process
– minimal or no energy available
Fiber types
 cellulose
 pectins
 lignins
 resistant starches
– classified as fibers
– escape digestion and
absorption
Fiber Characteristics
 soluble fibers, viscous, fermentable
– easily digested by bacteria in colon
– associated with protection against heart
disease and diabetes
 lower cholesterol and glucose levels
– found in legumes and fruits
Fiber
1. The average American does not get
enough FIBER in their diets.
2. The National Cancer Institute
recommends that the average person
gets 20-35 GRAMS of fiber every day.
3. Two other common names for fiber are:
ROUGHAGE or CELLULOSE.
4. Fiber is important because it attracts
WATER to the INTESTINES and helps
move food through our systems faster.
You have to have water along with fiber
or it is not as effective.
5. Benefits of fiber include a lowered risk of
DIVERTICULITUS, HEMORRHOIDS and
COLON or RECAL CANCER.
6. List the two types of fiber and the main
functions they perform:
7. Fiber only comes from PLANT food
sources. You CANNOT get fiber from
animal food sources.
8. Foods that are high in fiber include:
• Fruits and Veggies (Especially the
Skins!)
• Whole Grains
• Legumes/Beans
• Bran
9. Ways to increase fiber in the diet include:
• Add Whole Grains (At least 3 oz. per
day)
10. Label the Wheat Kernel below:
A.__ENDOSPERM___
Provides:
Starch
Protein
B. __GERM___
Provides:
Unsaturated Fatty Acids
“B” Vitamins
Vitamin E
Iron
Zinc
Other Trace Minerals
C. __Bran___
Provides:
Fiber
Vitamins
Minerals
11.When a product claims that it is “Whole
Wheat” or “Whole Grain”, it must use
the ENTIRE wheat kernel, or ALL
THREE parts.
12.Other products, like white bread and
rice, usually only use the
ENDOSPERM, which is the LEAST
beneficial part of the wheat kernel.
13.ENRICHED: some of the nutrients that
were lost in processing are added back
into the product.
14.FORTIFIED: 10% more of the Daily
Fiber
 insoluble and not easily fermented
– promote bowel movements
– alleviate constipation
– found in grains and vegetables
DRI and Fiber
 distinguish fibers by source
– dietary fibers: naturally in intact plants
– functional fibers: extracted from plants or
manufactured
– total fiber: sum of the 2
Carbohydrate Digestion
 break down into glucose
– body is able to absorb and use
 large starch molecules
– extensive breakdown
 disaccharides
– broken once
 monosaccharides
– don’t need to be broken down
Carbohydrate Digestion
 begins in mouth
– chewing releases saliva
– enzyme amylase hydrolyzes starch to
polysaccharides and maltose
 stomach
– no enzymes available to break down
starch
– acid does some breakdown
– fibers in starch provide feeling of fullness
 small intestine
– majority of carbohydrate digestion
takes place here
– pancreatic amylase reduces carbs to
glucose chains or disaccharides
– specific enzymes finish the job
 maltase
–maltose into 2 glucose
 sucrase
–sucrose into glucose and fructose
 lactase
–lactose into glucose and
galactose
 large intestine
– 1-4 hours for sugars and
starches to be digested
– only fibers remain
 attract water, which softens
stool
– bacteria ferment some fibers
 water, gas, short-chain
fatty acids (used for
energy)
Carbohydrate Absorption
 glucose can be absorbed in the mouth
 majority absorbed in small intestine
– active transport
 glucose and galactic
– facilitated diffusion
 fructose
 smaller rise in blood glucose
Lactose Intolerance
 more lactose is consumed than can be
digested
– lactose molecules attract water
 cause floating, abdominal discomfort,
diarrhea
– intestinal bacteria feed on undigested
lactose
 produce acid and gas
Lactose Intolerance
 age, damage, medication, diarrhea,
malnutrition
 management requires dietary change
– 6 grams (1/2 cup) usually tolerable
– take in gradually
– hard cheeses & cottage cheese
– enzyme drops or tablets
 lactose free diet is extremely difficult to
accomplish
Carbohydrate Metabolism
1/3 of body’s glycogen is stored in liver
– released as glucose to bloodstream
1. eat – intake glucose
2. liver condenses extra glucose to glycogen
3. blood glucose falls
4. liver hydrolyzes glycogen to glucose
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Glycogen is bulky, so we store only so much:
short term energy supply
Fat is the long term energy supply.
Glucose for Energy
 enzymes break apart glucose – yielding
energy
 inadequate supply of carbohydrates
– ketone bodies (fat fragments) are an
alternate energy source during starvation
– excess ketones can lead to ketosis:
imbalance of acids in body
 minimum of 50 – 100 grams of carbs/day
are needed to avoid ketosis
Glucose Homeostasis
 maintaining an even balance of glucose is
controlled by insulin and glucagon
– insulin
 moves glucose into the blood
– glucagon
 brings glucose out of storage
 maintaining balance
– balanced meals at regular intervals
 fiber and some fat slow the digestive
process down
 glucose gets into the blood slow and
steady
1
Intestine
Maintaining
Blood
Glucose
Homeostasis
When a person eats,
blood glucose rises.
2
Pancreas
High blood glucose stimulates
the pancreas to release insulin.
Insulin
3
Insulin stimulates the uptake of
glucose into cells and storage
as glycogen in the liver and
muscles. Insulin also stimulates
the conversion of excess
glucose into fat for storage.
Liver
Fat cell
Muscle
4
As the body's cells use
glucose, blood levels decline.
5
Pancreas
Glucagon
6
Glucose
Insulin
Glucagon
Glycogen
Low blood glucose stimulates
the pancreas to release
glucagon into the bloodstream.
Glucagon stimulates liver
cells to break down glycogen
and release glucose into the
blood.a
Liver
a
The stress hormone
epinephrine and other hormones
also bring glucose out of storage.
7
Blood glucose begins to
rise.
Imbalance
 diabetes
– after food intake, blood glucose rises and
is not regulated because insulin is
inadequate
 hypoglycemia
– blood glucose drops dramatically
 too much insulin, activity, inadequate
food intake, illness
 diet adjustment includes fiber-rich carbs
and protein
Glycemic Index
 way of classifying
food according to
their ability to raise
blood glucose
 much controversy
Sugar
 ½ comes from natural sources, ½ from
refined and added
– sucrose, corn syrup, honey
 excess can lead to nutrient deficiencies
and tooth decay
– empty calories
– sugar and starch break down in the
mouth
Sugar
 recommended intake
– added sugar = no more than 10% of energy
intake
Starch and Fiber
 diet that includes starch, fiber and natural
sugars
– whole grains, vegetables, legumes, fruits
 may protect against heart disease and
stroke
 reduces the risk of type 2 diabetes
 enhances the health of the large
intestine
 can promote weight loss
Starch and Fiber
 starch intake
– 45-65%
– 225 – 325 grams (DV is 300
grams)
– 900-1300 kcal/2000 kcal
– RDA is 130 grams
 fiber intake
– Daily Value is 25 grams/2000
kcal
Groceries
 grains: 1 serving = 15 grams
 vegetables
– ½ cup starchy = 15 grams
– ½ cup nonstarchy = 5 grams
 fruit: 1 serving = 15 grams
 milk: 1 cup = 12 grams
 meat: none or little
 legumes: ½ cup = 15 grams
Artificial Sweeteners
 help keep sugar and energy intake down
 anything we eat has FDA approval
– saccharin
– aspartame
– acesulfame potassium
– sucralose
– neotame
Sugar Replacers
 sugar alcohols
– provide bulk and sweetness
 cookies, gum, candy, jelly
– do contain minimal kcal
– low glycemic response
 absorbed slowly
– do not cause dental caries