Chapter8

what are the three main functions of carbohydrates

primary source of energy

spares body protein

prevents ketosis

carbohydrates provide how many kcals/gram

4

carbohydrates are the primary source of energy for

the brain and RBC’s

the brain and RBC’s can only use

glucose as an energy source

ketosis is

a metabolic process

ketosis occurs when

the body does not have enough glucose(preferred energy source for many cells) for energy, it burns stored fats instead

ketosis result in

a buildup of acids called ketones within the body

simple carbohydrates include

monosaccharides and disacchrides

complex carbohydrates include

olugosaccharides and polysaccharides

examples of polysaccharides

glycogen, strach, fiber

glucose is an example of a

monosaccaride

fructose is an example of a

monosaccaride

galactose is an example of a

monosaccaride

sucrose is an example of a

disaccharide

maltose is an example of a

disaccharide

lactose is an example of a

disaccharide

sucrose is composed of

glucose + fructose

maltose is composed of

glucose + glucose

lactose is composed of

galactose + glucose

glucose is in

most common foods

fructose is in

fruit, honey, high fructose corn syrup

glactose is in

milk and dairy products

sucrose is in

table sugar, sugar cane, beets and honey

maltose is in

malt beverages, malt beer

lactose is in

milk and dairy products

another name for sucrose is

table sugar (added to foods to make them sweeter)

very few foods contain

maltose

another name for lactose is

milk sugar

Proven health issue associated with simple sugar intake

Tooth decay

Issues regarding simple sugars that are under investigation

• high BMI
• osteoporosis in later life
• Diabetes Mellitus

reccomended simple sugar intake is

<10% of total kcal/d

=200 kcal

=50 g

examples of non-sugar sweeteners

saccharin, acesulfame K, aspartame, sucralose, stevia and sugar alcohols

The first artificial, 0 kcal sweetener (1880’s)

saccharin

what non sugar sweetener was banned in 1977

saccharin but it is back on the market today

saccharin brand name

sweet’nlow

acesulfame K is an

artifcial, 0 kcal sweetener

acesulfame K brand name

sweet one

aspartame is a

nutritive, artifical sweetner

what is the structure of

aspartame is _____ times sweeter than sugar

sucralose is a

0 kcal, artificial sweetener

sucralose is made from

sucrose

which non sugar sweetener has a bitter aftertaste

sucralose

sucralose is ____x sweeter than normal sugar

600

is sucralose heat stable

yes

sucralose brand name

splenda

stevia is a

0 kcal, non-nutritive sweetner

stevia is derived

stevia brand name

truvia

structure of sugar alcohols

sugar with alcohol groups

types of sugar alcohols

sorbitol, manitol, xylitol

benefits of suagr alchols

• provide less kcal than sugar

• do not readil promote tooth decay

side effects of sugar alcohols

Can cause diarrhea if consumed in excessive amounts

complex CHO are called

polysaccharides

structure of polysaccharides

polymer of glucose (many sugars linked)

what is the storage form of glucose in a plant

starch

what is the structure of starch

linear chain of glucose where glucose molecules are bonded through α 1-4 glycosidic bonds

starch branch structures

some through the α 1-6 glycosidic bonds

what is the storage from of glucose in animals and humans

glycogen

major sites of glycogen stoage

liver and muscle

structure of glycogen

linear chain of glucose where glucose molecules are bonded through α 1-4 glycosidic bonds

glycogen branched structures

highly branched strucutre (

Benefit of highly branched structure of glycogen:

many glucose molecules can be quickly broken down from the branches to produce energy when exercising or for fly or flight response

structure of fiber

linear chain of glucose where glucose molecules are bonded through β1-4 glycosidic bonds which is not digested by human digestive system

fiber provides

various health benefits

classifications of fiber

soluble and insoluble

humans cannot digest

dietary fiber

soluble fiber forms

a gel-like substance in gastrointestinal tract

soluble fiber binds

substances such as bile, glucose, minerals etc.

soluble fiber promotes

growth of beneficial intestinal bacteria

food sources of soluble fiber

dried beans, oats, apples

soluble fiber decreases

cholesterol, BP and CVD

solubles fiber lowers the risk for

blood glucose (type 2 DM)

insolue fiber passes

through gastrointestinal tract unchange

insoluble fiber helps

food move through your digestive system

food sources of insoluble fiber

whole grain, wheat bran and veggies

insoluble fiber prevents

constipation, hemorrhoids and diverticular disease

insoulbe fiber reduces

colon cancer risk

diverticular disease results when

samll, protruding pouches called diverticula form along the wall of the large intestine

recommended fiber intake for females (19-50)

25 grams

what is hte recommended fiber intake for males (19-50)

38 grams

what is the current fiber intake

14 mg

AMDR for CHO

45-65% of total dailt calories

based on 200 kcal diet: 225-325 grams

key enzyme for starch digestion in the mouth

salivary α-amylase

salivary α-amylase provides

partial digestion

key enzymes in the small intestine for starch digestion

• Pancreatic α-amylase
• Maltase/ lactase/sucrase
• α-dextrinase

disaccharide digestion occurs

on the brush border of the small intestone

lactose intolerance occurs because

there is no lactase in the small intestine

absorption of monosaccharides occurs in the

small intestine