Chapter 4 Flashcards
What are Monosaccharides ?
Mono= one saccharide= sugar hex=6 each contain 6 carbon 12 Hydrogens, and 6 Oxygen carbohydrates
Examples of Monosaccharides?
- Glucose
- Fructose
- Galactose
What are Disaccharides?
Pairs of monosaccharides linked together
How do you make a Disaccharide?
A chemical reaction known as condensation links two monosaccharide together
What is Condensation?
a chemical reaction in which water is released as two molecules combine to form one larger product
To break the disaccharide in two?
a chemical reaction known as the Hydrolysis occurs
What is Hydrolysis?
a chemical reaction in which one molecule is split into two molecules, with hydrogen added to one and a hydroxyl group to the other
Hydro=water
lysis=break
Hydrolysis commonly occurs when?
during digestion
Is Maltose a disaccharied true or false?
True
Maltose
composed of two glucose units; sometimes known as malt sugar
is Sucross a Disaccharide true or false
True
What two monosaccharides create Sucrose?
Fructose and Glucose
What is sucrose?
It is a combo of fructose and glucose and is the sweetest of the disaccharides because ti contains fructose, and fructose is the sweetest of the monosachharides.
Where can you find these sugars Fructose and glucose?
fruits, vegetables
To make table sugar?
sucrose is refined from the juices of sugarcane and sugar beets, then granulated brown or white
lactose is a disaccharide true or false?
true
what combination makes lactose
galactose and glucose
what are polysaccharides?
compunds composed of many monosaccharides linked together.
what is a oligasaccharide?
an intermediate string of 3-10 monosaccharides
example of polysaccharides?
glycogen
starches
fiber
where is glycogen found?
some meats
Glycogen has an important role in the body what is it?
It stores glucose for future use as glycogen
how does glycogen know to release glucose for energy?
when the hormonal message “release energy” arrives at at liver or muscle cell, enzymes respond by attacking the many branches of glycogen making a surge of glucose available.
plant cells store glucose as?
starches, long branched or unbranched chains
All starchy foods come from?
plants
The richest food source of starch are?
grains
What is a starch?
plant polysaccharides composed of many glucose molecules
what are the structural parts of plants and are found in all plant derived foods-vegetables, fruits, whole grains, and legumes.
Fibers (dietary fibers)
dietary fibers differ from starches how?
the bonds between their monosaccharides cannot be broken down by digestive enzymes in the body. for this reason dietary fibers are often described as nonstarch polysccharides.
Because dietary fibers pass through the body undigested , they contribute?
no monosaccharides and therefore little energy
some dietary fibers dissolve in water
soluble fibers, form gels and are easily digested by bacteria in the colon (fermentatable)
dietary fibers that dissolve in water are?
oats, barley, legumes, and citrus fruits,
soluble fibers are most often associated with?
protecting against heart disease and diabetes by lowering blood cholesterol and glucose levels, respectively
fibers that do not dissolve in water are called?
insoluble fibers, because they do not form gels which make them less readily fermentable.
insoluble fibers are found in?
whole grains(bran) and veggies
insoluble fibers promote?
bowel movements, alleviae constipation, and prevent diverticular disease
what are functional fibers?
when fibers have been extracted from plants or are manufactured and then added to foods or used in supplements and we use them to relive consipation
Total fiber refer to?
the sum of dietary fibers and functional fibers
a few starches are classified as dietary fibers and they are known as?
resistant starches
Resistant starches do what?
they escape from digestion and absorption in the small intestine
why would starch escape digestion or absorption?
the body’s efficiency in digesting starches and the food’s physical properties
Resistant starches are common in?
whole or milled grains, legumes, and just-ripened bananas.
Cooked potatoes, pasta, and rice that have been chilled also retain resistant starches
what does resistant starch promote
a healthy colon
phytic acid is found in?
fiber rich foods could be preventing absorption but no proof yet of this. this binding prevents a risk of mineral deficiencies but risk is low if total intake is less than 40 grams a day
what is viscous?
gel-like consistency
the ultimate goal of digestion and absorption of sugars and starches is?
to break them into small molecules-chiefly glucose-that the body can absorb and use.
when a person eats foods containing starch?
enzymes hydrolyze the long chains to shorter chains, the short chains to disaccharides, and finally the disaccharides to monosaccharides and this process begins in the mouth
in the mouth chewing high-fiber foods does what?
slows eating and stimulates the flow of saliva
what is amylase?
an enzyme that hydrolyzes starch to shorter polysaccharides and to the disaccharide maltose in the mouth.
carbohydrate digestion takes place in?
mouth, small intestine
the stomachs digestive juices contain no enzymes to break down?
carbohydrates
what isn’t digested in the stomach and lingers delaying gastric emptying providing fullness
Fibers
what organ provides most of the work of carbohydrate digestion
small intestine
what is a major carbohydrate-digesting enzyme that enters the intestine via the pancreatic duct
pancreatic amylase, continues breaking down the polysaccharides to shorter glucose chains and maltose
where does the final step of digestion in the small intestine take place?
outer membrane of the intestinal cells.
enzymes on the outer membrane of the intestinal cells that break down specific disacchareds are?
maltase
sucrase
lactase
what is satiety?
the feeling of fullness and satisfiaction that occurs after a meal and inhibits eating until the next meal.
what determines how much time passes between meals?
satiety
After 1-4 hours after a meal what has been digested?
all sugars and most of starches, only the fibers remain
Fibers in the Lg. intestine attract?
water, which softens the stools for passage without straining
bacteria in the GI tract ferment some?
what does this generate?
fibers
generate water gas and short chain fatty acids
Metabolism of short chain fatty acids also occurs where?
cells of the liver
how do does glucose and galactose enter the cells lining in the small intestine?
by active transport
how is fructose absorbed in the small intestine?
facilitated diffusion
fructose and galactose are mostly metabolized in the?
liver
where does glucose go?
out of the body’s cells for energy
what is lactose intolerance?
a condition that results from the inability to digest the milk sugar lactose
symptoms of lactose intolerant
after consumption of lactose; bloating gas, abdominal discomfort, and diarrhea
what is a milk allergy?
caused by an immune reaction to the protein in milk
when is Lactase activity at its highest
immediately after birth
what happens to the undigested lactose for lactose intolerant people?
lactose becomes food for intestinal bacteria , which produce irritating acid and gas contributing further to discomfort and diarrhea
causes of lactose intolerance?
age, when intestinal villi are damaged by disease, certian medicines like anti-inlammatorys, prolonged diarrhea, or malnutrition
lactose malabsorption may be temporary or permanent true or false?
true
the prevalence of lactose intolerance is lowest among?
Scandinavians and other northern Europeans
the prevalence of lactose intolerance is highest among?
Native Americans and Southeast Asians
how many people in the united states are lactose intolerant
an estimated 30-50 million people
what deficiencies can you have if you give up milk without supplementing
mineral calcium, Vitamin D, B vitamin riboflavin
how many grams of milk can a lactose intolerant person consume without symptoms?
6grams of lactose which is 1/2 cup of milk
what can you eat that seems to improve lactose intolerance
yogurt with live bacteria
yougurt and kefir can be tolerated by
lactose intolerant people because the bacteria digest lactose for their own use reducing the lactose content
what is kefir?
a fermented milk created by adding Lactobacillus acidophilus and other bacteria tht break down lactose in glucose and galactose, producing a sweet, lactose free product
Foods that have lactose
whole-wheat bread Dinner roll cheese doghnut (cake type) chocolate candy sherbet cottage cheese ice cream milk yogurt(low-fat)
20% of perspiration drugs and 5% over the counter contain?
lactose as a filler
sugars attached to a protein do what to the protein?
change its shape and function and when the protein binds to a lipid in the cells membrane, sugars alter the way cells recognize one another.
Glucose plays the central role in?
carbohydrate metabolism
what does the body use as the chief energy nutrient?
glucose
after a meal what rises?
blood glucose
after a meal blood glucose rises and what do the liver cells do?
link excess glucose molecules by condensation reactions into long, branching chains of glycogen
when blood glucose falls what do the liver cells do?
break down glycogen by hydrolysis reaction into single molecules of glucose and release them into the bloodstream.
after hydrolysis breaks glycogen down into molecule of glucose and releases glucose into the bloodstream what becomes available to supply energy to the brain and other tissues?
glucose
The liver stores about how much glycogen?
one-third of the body’s total and releases glucose in the bloodstream as needed
the brain maintains a small supply of what ____ for emergency energy reserves during times of glucose deprivation?
glycogen
what fuels the work of most of the body’s cells?
Glucose
inside a cell,a series of reactions can break glucose into smaller compounds that?
yield energy when broken down completely to carbon dioxide and water
What is the preferred energy source for brain cells, other nerve cells and dev. red blood cells?
Glucose
To keep providing glucose to meet the body’s energy needs, a has to eat?
carbohydrate-rich foods frequently
when a person does not replenish glucose by eating carbs?
body proteins are broken down to make glucose to fuel the brain and other special cells. these body proteins derive primarily from the body’s liver and skeletal muscles.
the conversion of protein to glucose is called?
gluconeogenesis
what is gluconeogenesis
the making of new glucose
what is the protein sparing action?
the action of carbohydrate in providing energy
inadequate supply of carbs can shift the body’s energy metabolism how?
fat takes an alternative metabolic pathway, instead of entering the main energy pathway, fat fragments combine with one another, forming ketone bodies.
what are ketone bodies?
provide an alternate fuel source during starvation, but when their production exceeds their use, they accumulate in the blood, causing ketosis
what is ketosis
an undesirably high concentration of ketone bodies in the blood and urine
to spare body protein and prevent ketosis the body needs?
50 to 100 grams of carbohydrates day
if the blood glucose falls below normal a person may become?
dizzy or weak
if blood glucose rises too high a person may experience?
fatigued
fluctuations to the extremes untreated can become?
fatal
after a meal blood glucose rises and special cells of the pancreas respond how?
by secreting insulin into the blood
blood glucose homeostasis is regulated primarily by two hormones called?
insulin and glucagon
what does insulin do?
moves glucose from the blood into the cells
what does glucagon do?
brings glucose out of storage when necessary
elevated blood glucose returns to normal levels as?
excess glucose is stored as glycogen and fat
another hormone besides glucagon that signals the liver cells to release glucose is?
the fight or flight hormone called epinephrine and this happens when the body experiences stress. It does this by acting to release glucose from the liver glycogen to the blood.
the maintenance of normal blood glucose depends on?
foods and hormones, because when glucose falls below normal food can replenish it, in the absense of food glucagon can signal the liver to break down cells to take glucose for energy
eating balanced meals that provide abundant carbs, including fibers, and a little fat help to?
slow down the digestion and absorption of carbs so that glucose enters the blood gradually. Eating at regular intervals creates a balance as well.
blood glucose regulation fails and two conditions are the result?
diabetes or hypoglycemia
plan diets and exercise to help regulate blood sugar
Diabetes?
blood glucose rises after a meal and remains above normal levels because insulin is either inadequate or ineffective.
there are two main types of Diabetes?
Type 1 and Type 2
Type 1 Diabetes
less common
the pancreas fails to produce insulin
cause? maybe certain viruses activate the immune system to attack and destroy cells in the pancreas as if they were foreign cells
Type 2 Diabetes
more common
the cells fail to respond to insulin
tends to occure as a consequence of obesity
best prevention of Diabetes 2
maintain a healthy body weight
hypoglycemia
an abnormally low blood glucose concentration
should blood glucose drop below normal a person would experience the symptoms of?
hypoglycemia
symptoms of hypoglycemia?
weakness, rapid heartbeat, sweating, anxiety, hunger, and trembling
people with hypoglycemia need to do what?
replace refined carbs with fiber rich carbs and insure protein intake and eat smaller meals and eat more frequently
what is the glycemic response?
refers to how quickly glucose is absorbed after a person eats, how high blood glucose rises, and how quickly it returns to normal
lowering the glycemic index of the diet may improve?
glucose control
improving blood lipids and reduce he risk of heart disease, help with weight management as well. However this is not supported by science research so there is no proof this works.
what is glycemic index?
a method of classifying foods according to their potential for raising blood glucose
what is dextrose?
the name food manufacturers use for the sugar that is chemically the same as glucose
invert sugar
used as a food additive to help preserve freshness and prevent shrinkage. it is fructose and glucose formed by hydrolysis of sucrose in a chemical process
manufactures prefer high-fructose corn syrup because?
it retains moisture, resists drying out, controls crystallization, prevents microbial growth and blends easily with other sweeteners, acids, and flavorings
an indicator of pre-diabetes
handling of glucose becomes unbalanced and insulin resistance develops
added sugars can cause
risk of diabetes, inflammation, hypertension, and heart disease
honey and sugar end up as what in the body?
glucose and fructose they are equal honey is not better for you. the only difference is honey contains a few vitamins and minerals. both similar in nutrition
tooth decay can be caused by?
natural sugars and added sugars, bacteria in the mouth ferment the sugars and then produce an acid that erodes tooth enamel
what is dental cariers
tooth decay
if a person eats three pieces of candy at one time and doesnt brush and floss right away
teeth will be exposed to 30min of acid destruction and the longer you take to eat them the longer the exposure of acid after. milk and cheese with sweets help prevent so much of this.
What is dental plaque
saliva that cleanse the mouth, the minerals that form the teeth, and the foods that remain after swallowing.
the only thing I can find good about using sugar alcohols
the do not contribute to dental caries. you can find this valuable in chewing gum, breath mints, and other products people keep in their mouth for a while
what are sugar alcohols (some sugar free contain this)?
sugar like compounds that can be derived from fruits or commercially produced from dextrose also called polyols
Artificial sweeteners are sometime called?
nonnutritive sweeteners because they provide no energy
stevia
herbal sweetner
derived from plant leaves FDA votes safe
Examples of sugar alcohols
erythritol, isomalt, lacitiol, maltitol, mannitol, sorbiol, xylitol
all these have in common? mostly all end in ol or itol
foods rich in soluble fibers lower blood cholesterol by?
binding with bile acids in the GI tract and increasing their excretion. Consequently, the liver must use its cholesterol to make new bile acids. in addition bacterial by products of fiver fermentation in the colon also inhibit cholesterol synthesis in the liver. the net result is soluble fibers found in oats lower blood cholesterol
how does high fiber foods help with Diabetes type 2
soluble fibers trap nutrients and delay their transit through the GI tract, glucose absorption is slowed, which helps to prevent glucose surge and rebound
how do dietary fibers enhance the health of the GI/Large intestine
insoluble fibers such as cellulose increase stool weight, ease passage, and reduce transit time. also help soften stools and keep rectal veins from swelling. also stimulates the GI tract muscles so they retain their strength and resist bulging out into pouches known as diverticula
how does a high fiber diet protect you from colon cancer?
by diluting, binding, and rapidly removing potential cancer-causing agents from the colon
soluble fibers stimulate bacterial fermentation of resistant starch and fiber in the colon, a process that produces short-chain fatty acids that lower the pH.
these small fat molecules activate cancer-killing enzymes and inhibit inflammation in the colon.
how does high fiber foods help with weight management
by delivering less energy per bite.
as fibers absorb water from the digestive juices, they swell, creating feelings of fullness, lowering food intake, and delaying hunger
what should we buy to help with weight management with fiber
whole grains, legumes, fruits, and vegetables
harmful effects of excessive fiber intake?
a person who has a small capacity and eats mostly high fiber foods may not be able to eat enough food to meet energy or nutrient needs.
switching to a low-fiber to a high-fiber diet can cause
temporary bouts of abdominal discomfort, gas, diarrhea, more seriously can obstruct the GI tract. you must increase fiber gradually over several weeks to give GI tract time to adapt to prevent this. Also, drink plenty of liquids and make sure to select the fiber rich foods.
recommended intakes of starch and fiber
half of 45 to 65 % of the energy requirement a person consuming 2000 kcalories a day should be having 900 calories of carbs
how much fiver does the FDA say we should have?
11.5 grams per 1000 kcalories for our daily intake of kcalories
too much fiber can cause?
GI problems for some people
starchy veggies like corn, peas, or potatoes provide about what for carbs?
15 grams of cars per half-cup of serving
a serving of nonstarchy veggies such as half-cup of broccoli, green beans, or tomatoes provide what for carbs?
5 grams
a fruit serving like a small banana, apple, or orange or a half cup of most canned or fresh fruit
contains an average of about 15 grams of carbs
a serving (a cup) of milk or yogurt provides about?
12 grams of carbs
legumes provide about
20 grams of carbs a 3rd from fiber
if you subtract the grams of fibers and sugars from total carbs you get?
the grams of starch
