Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

66 Cards in this Set

  • Front
  • Back
Functions of Carbohydrates
-Major fuel source for the body
-Primary fuel source for nervous system and RBC
How much carbs are stored in the body as glycogen?
Limited amounts stored in body (as glycogen)
general formula of carbs:
General formula: (CH2O)n
General classification of Carbs:
types of monosaccharides:
what is the principal monosaccharide in the body?
another name for glucose?
blood sugar
3 characterisctics of Fructose:
Almost all is metabolized to glucose in the liver
Found in fruit, honey, sucrose (table sugar) and high-fructose corn syrup
Makes up ~8-10% of total energy intake in North America
3 characterisctics of Galactose:
Not usually found free in nature
Usually bound with glucose (to form lactose)
Converted to glucose in the liver
Two monosaccharides held together by a glycosidic bond
Condensation reaction (water is produced)
Two forms of glycosidic bonds:
Alpha glycosidic bond
Beta glycosidic bond
Maltose (Glucose + Glucose) --alpha bond
Sucrose (Glucose + Fructose) --alpha bond
Lactose (Galactose + Glucose) --beta bond
Sources of Disaccharides
Sucrose: common table sugar (beet or cane), maple syrup
Lactose: primary sugar in milk and milk products
Maltose: the breakdown of polysaccharides
Sucrose: sucrase
Lactose: lactase
Maltose: maltase
3 types of complex carbs
Oligosaccharides: raffinose & stachyose

Polysaccharides: Starch & Glycogen

Dietary fiber
Characteristics of Oligoaccharides
Contain 3 to 10 monosaccharides
Two primary ones are raffinose and stachyose (found in legumes such as beans)
Not digested by human enzymes
Therefore, metabolized by bacteria in the large intestine
Beano®: enzyme preparation (made from mold) that breaks down many oligosaccharides in small intestine
Characterisitics of Polysaccharides
Up to 1,000 or more monosaccharides bonded together
What kind of bonds does starch have?

2 types of starch?

What is ratio of starch?
Starch: incorporates alpha glycosidic bonds

Amylose--straight chain polymer
Amylopectin--highly branched polymer

Typical ratio is 1:4 (amylose to amylopectin)
properties of Amylopectin
Amylopectin: increases blood glucose much more readily because numerous branches provide more sites for enzyme activity
Amylopectin: also forms very stable gel (i.e., retains water very well)
properties of glycogen
Storage form of CHO for animals and humans
Structure similar to amylopectin but with more branching
Therefore, more sites for enzyme action
Found mainly in the liver (~400 kcal) and muscles(~1400 kcal)
Muscle glycogen cannot yield blood glucose
what is the storage form of CHO for humans and animals?
name the souble fiber and insoluble fibers?
Insoluble fiber:
Cellulose, hemicellulose, lignin (non-CHO)
Forms the structural part of plants
Poorly fermented by the bacteria in the colon
Soluble fiber:
Gums, Pectins, Mucilages
Found inside and around plant cells (i.e., is the glue)
Sources: fruits, vegetables, rice bran, psyllium seed
Fermented by bacteria in the colon
Bacterial Metabolism of Soluble Fiber:
Produces short-chain fatty acids (SCFA)
Acetic acid (C=2)
Propionic acid (C=3)
Butyric acid (C=4)
SCFA provide fuel source for intestinal cells
Thus, enhance the health of the cells of the large intestine
Also absorbed into the blood stream
Soluble dietary fiber yields ~1.5 to 2.5 kcal/g
saliva contains...
8 benefits of dietary fiber
Promotes softer, larger stool and regularity
Reduces hemorrhoids and diverticula
Slows glucose absorption
Reduces blood cholesterol by inhibiting cholesterol absorption
Therefore reduces cardiovascular disease
Reduces incidence of some cancers
Aids in weight control (↓ kcals)
Adults whose main CHO source is low-fiber foods: much more likely to develop diabetes
4 functions of Functions of Carbohydrate
Functions of Carbohydrate:
Supplies energy to body cells

Spares protein: if not enough CHO is consumed, body makes glucose from protein found in muscle tissues

Prevents ketosis: if CHO intake is low you get incomplete metabolism of fat which results in formation of ketones

Monosaccharide Metabolism...What happens in portal vein and what happens in the liver?
Monosaccharide Metabolism
Portal Vein:
Transports absorbed monosaccharides
Delivers them to the liver
Liver transforms fructose and galactose to glucose
Liver can:
Release glucose back to the blood stream
Store glucose as glycogen
Convert glucose to fatty acids
CHO Absorption...
Glucose and Galactose
CHO Absorption
Glucose and Galactose
Active absorption using a sodium pump
Energy is expended to pump the sodium back out of the cell
Going from low concentration to high
Facilitated diffusion using a carrier
No energy expended, therefore, slower process
Recommended CHO Intake?
Recommended CHO Intake
Need 50 to 100 g of CHO/day to prevent ketosis
Newly established RDA: 130 g/day for adults
AMDR for CHO is 45 to 65% of TEI
Reasonable goal:
45% of TEI from starch
55-60% of TEI from total CHO
Current North American intake:
180-330 g of CHO/day (primarily from white bread, soft drinks, baked goods, potatoes)
50% of TEI is from CHO
Recommended Dietary Fiber Intake ??
Recommended Dietary Fiber Intake
25 g/day for women; 38 g/day for men
Standard: 14 g/1000 kcal
Children: their age +5g/day
Ave. U.S. intake: 14 to 19 g/day
Half of breads/cereals should be whole grains! (current average: <1 serving daily)
Too much fiber (>60 gm/d) will:
require extra intake of fluid
bind to some minerals (e.g., Zn and Fe)
develop blockage of intestine
fills the stomach of a young child too quickly
Recommendation for Simple Sugar Intake???
Recommendation for Simple Sugar Intake
Sugar: low nutrient density
Recommend no more than 10% of TEI from “added sugars “
Ave. U.S. intake: 16% of TEI
Added sugars: sugars added to food and beverages during processing; does not include lactose from milk or
fructose from fruit
4 Problems with High-Sugar Diets...
Empty calories
(Soda has replaced milk)

Calories add to excess weight

Dental caries: Bacteria in mouth metabolize sugars into acids which dissolve and weaken tooth enamel

High glycemic index. Blood glucose response of a given food
What factors influence Glycemic Index (GI)?
Starch structure
Food processing (cooking, etc.)
Physical structure (particle size)
Dietary fiber content of the food
Total fat and/or protein content of the food
All of the above determine digestion rate of the CHO
What are the refernece points for Glycemic Index?
Ex Low, Intermediate, High. Also, reference for food glucose?
Glycemic Index (GI)
Reference food glucose: 100

Low GI foods: <55
Intermediate GI foods: 55 → 70
High GI foods: >70
Examples of high GI foods: baked potatoes, mashed potatoes, short grain white rice, honey, jelly beans
Whay is glycemic load better than glycemic index?
Glycemic Load (GL)
Better reflects a food’s effect on blood glucose than GI alone (because it accounts for amount of CHO consumed)
GL = (GI/100) x amount of CHO found in a serving of the food
Baked potato GL = .85 x 57 g CHO/serving = 48
Reference points for lo, intermediate and high glycemic LOAD?
Glycemic Load (GL)
Low GL foods: <10
Intermediate GL foods: 11→20
High GL foods: >20
Effects of High GL CHO
Stimulates the release of significant amounts of insulin

Insulin increases fat synthesis in liver

Insulin increases blood triglycerides

Insulin increases fat deposition in adipose tissue

Insulin effects LDL (smaller particles)

Insulin causes a more rapid return to hunger after a meal

Insulin increases tendency for blood to clot

Over time, muscle tissue may become resistant to the insulin, resulting in insulin resistance and, eventually, type 2 diabetes in some people
Describe Lactose Intolerance...
Lactose Intolerance
Also referred to as “lactose maldigestion”
Present in ~75% of world population
Caused by reduction in lactase synthesis
Lactose is undigested and not absorbed
Lactose is metabolized by bacteria in large intestine
causes gas, bloating, cramping, discomfort and diarrhea
Primary lactose intolerance disease
Secondary lactose intolerance disease
What To Do If You Are Lactose Intolerant
Determine total amount you can tolerate
Nearly all with lactose intolerance can tolerate ½ to 1 cup of milk with meals
Eat dairy with fat
Cheese is usually tolerated well
Yogurt is usually tolerated well
because of live bacterial cultures
Use of Lact-Aide
Use low-lactose dairy products
What is the benchmark for comparing sweeteners ?
5 types of nutritive sweeteners?
High-fructose corn syrup
40 to 90 % fructose (usually ~55%)
cornstarch is treated with acid and enzymes
conversion of some of glucose into fructose
same degree of sweetness as sucrose
cheaper and used in many food products

Brown sugar

Maple syrup

Honey – caution, not safe for infants, may contain Clostridium botulinum spores

Sugar alcohols
sorbitol, mannitol, xylitol
~1.5 to 3 kcal/g
Absorbed and metabolized to glucose more slowly
Large amounts can cause diarrhea
Used in sugarless gums, candy, etc.
Not readily metabolized by bacteria in mouth – less of a problem with dental caries
4 types non-nutritive sweeteners
All yield little or no energy when consumed in typical amounts
what is not recommended for people with phenylketonuria (PKU)
what is the normal fasted blood glucose:
between 70 and 99 mg/dl
Symptoms of diabetes
Frequent urination
Extreme thirst
Weight loss
Eventual death
Diagnostic criteria for diabetes:
Diagnostic criteria:
Diabetic – fasting blood glucose >125 mg/dl of blood
Prediabetic – fasting blood glucose of 100 to 125 mg/dl of blood
New diabetes diagnostic tool:
hemoglobin A1c
Diabetes leads to ____ deatsh each yr
diabetes effects ____ percent population
Blood Glucose Control:
What is the role of the liver and the pancreas??
Liver: Main organ for regulating amount of glucose that enters bloodstream

Role of the pancreas:
Releases insulin (when blood glucose is high)
Releases glucagon (when blood glucose is low)
Ratio of insulin to glucagon determines action
Goal is to maintain blood glucose homeostasis
Blood Glucose Control:
Role of Pancreas
Releases insulin (when blood glucose is high)
Releases glucagon (when blood glucose is low)
Ratio of insulin to glucagon determines action
Goal is to maintain blood glucose homeostasis
4 Functions of Insulin:
Promotes glycogen synthesis and storage
Increases glucose uptake by the muscle cells, adipose cells, and others
Reduces gluconeogenesis by liver
Net effect: lowers blood glucose
4 Functions of Glucagon:
Counteracts the effects of insulin
Breaks down glycogen in liver (but not in muscle)
Enhances gluconeogenesis in the liver
Net effect: raises blood glucose
Hormonal Influences on Insulin
Released by adrenal glands
“Fight or flight” response
Causes breakdown of glycogen
Raises blood glucose

Cortisol and growth hormone:
increases gluconeogenesis
raises blood glucose
What do most casesof Type 1 diabetes start with?
Most cases begin with immunological disorder
An autoimmune reaction set off by a virus or a protein foreign to the body
Immune system produces antibodies that attack the beta cells in the pancreas
Results in gradual destruction of insulin-producing beta cells
When (what age) does type 1 diabetes usually start?
late childhood, ages 8-14
What will untreated type 1 diabetes lead to?
Untreated Type 1 will lead to ketosis
More than ___% of the diabetes cases in N. America are ______ diabetes
Type 2
Type 2 diabetes occurs at what age?
Can occur at any age (most common is middle- to older-aged adults
type 2 diabetes patients do/do not require insulin therapy initially in their disease?
do not
What is the initial problem in Type 2 diabetes?
defective insulin receptors (i.e., insulin resistance)
What percent of cases of Type 2 diabetes is related to obesity??
Eventually, what percent of Type 2 diabetes pts will require insulin
What meds are used in Type 2 diabetes?
Glucophage – reduces glucose production by liver

Avandia – increases body’s response to its own insulin

Precose – delays CHO digestion and absorption
Does type 2 diabetes often disappear when weight is lost?
Consequences of Uncontrolled Blood Glucose... (7)
Ketosis leading to ion imbalances, dehydration, coma, death

Degenerative diseases

Nerve damage


Kidney disease


Increased risk for wound infections and amputations
Describe Gestational diabetes...
Brought on by pregnancy
During pregnancy, most women experience insulin resistance to some extent
Helps make glucose more available to fetus
In 4 to 7% of all pregnancies – gestational diabetes develops after 24th week – disappears within 6 weeks after delivery
Babies tend to be larger at birth
These women are at increased risk to develop Type 2 diabetes later
Describe Hypoglycemia...
Reactive hypoglycemia
Occurs 2-4 hours after eating a meal high in CHO
Possibly due to over-secretion of insulin?
Fasting hypoglycemia
Usually caused by pancreatic cancer or medications
Leads to overproduction of insulin
dietary treament measures for type 1 diabetes...
Dietary measures (to minimize swings in blood glucose):
3 regular meals and 1 or more snacks daily
Regulated CHO:Protein:Fat ratio
Diet rich in low glycemic load foods
Ample fiber, esp. soluble fiber
Moderate consumption of sugars with meals
CHO counting (amount of CHO in each food)