Nutrition Exam 2

What are carbohydrates composed of?

CHO

Types of simple sugars

monosaccharides

disaccharides

types of complex carbohydrates

oligosaccharides

polysaccharides

Example of a monosaccharide

glucose

fructose

galactose

sugar alcohols

pentoses

what monosaccharide is most abundant? where is it found?

glucose

blood sugar

what monosaccharide is the sweetest? where is it found?

fructose

fruit, honey, high-fructose corn syrup

How is lactose formed?

glucose + galactose

Where are pentoses found?

Ribose and deoxyribose

What do sugar alcohols do?

sweeten low or no-sugar foods

excess may cause GI upset

What are disaccharides?

2 monosaccharides joined together linked together by alpha or beta bonds

What determines if we can digest disaccharides

alpha bonds- digestible

beta bonds- indigestible

Examples of disaccharides, how they are formed, and where they are found

Maltose

• glucose + glucose

• seeds and alcoholic beverages

Sucrose

• glucose + fructose

• table sugar

Lactose

• glucose + galactose

• milk and milk products

What is an oligosaccharides

3-10 linked monosaccharides

examples of oligosaccharides and where they are found

raffinose and stachyose

onions, cabbage, broccoli, legumes

Are oligosaccharides digestible? why or why not

No, contain beta bonds

Examples of polysaccharides

Starch, glycogen, fiber

Examples of starches

Amylose and Amylopectin

Are starches digestible?

Yes

What is starch’s main function?

storage form of carbohydrates in plants

What is glycogens main function?

Storage form of carbohydrate in animals

storage is limited

Is glycogen digestible?

Not in our diet, but digestible

Is fiber digestible?

No

Examples of an indigestible fiber? and why it is indigestible

Cellulose, hemicellulose, lignin

we don’t have the enzymes to break beta bonds

Examples of soluble fiber

pectins, gums, mucilages, some hemicelluloses

Two types of fiber

Soluble and insoluble

Function of carbohydrates

provide energy

Which one of these contains whole grains?

Wheat flour/bread

Whole wheat flour/bread

Whole wheat flour/bread

Parts of a grain seed

Bran, endosperm, germ

What part of the grain seed do refined grains contain?

endosperm only

Two types of sweeteners

Nutritive and non-nutritive

What type of sweeteners provide energy?

nutritive

Examples of nutritive sweeteners

monosaccharides (glucose) and disaccharides, high-fructose corn syrup, sugar alcohols

Examples of non-nutritive sweeteners

saccharin

aspartame

sucralose

stevia

Functions of digestible vs indigestible carbs

Digestible

• primarily serve as a source of energy

• spare protein

• prevent ketosis

Indigestible

• improve bowel health

• improve blood glucose control

• reduce cholesterol absorption

• reduce obesity risk

Starch digestion in mouth

salivary amylase breaks down polysaccharides into smaller polysaccharides and disaccharides

Starch digestion in stomach

No chemical digestion

Small intestine and pancreas do what in carbohydrate digestion and what do they secrete?

responsible for most carbohydrate digestion

pancreatic amylase (poly into smaller poly and di)

intestinal enzymes (di to mono)

enzymes that break down

maltose

sucrose

lactose

maltase

sucrase

lactase

Where are indigestible carbs broken down

large intestine where bacterial enzymes digest select fibers and produce short-chain fatty acids and gas

What monosaccharide(s) use active transport

glucose and galactose

What monosaccharide(s) use facilitated diffusion

fructose

Monosaccharides are transported through ______ and used by cells as a source of energy

bloodstream

Where is excess glucose stored?

as glycogen in the liver and muscles

also converted to fat and stored in fat cells

Primary vs secondary lactose intolerance

Primary

• insufficiency of lactase production

Secondary

• due to conditions that damage lactase producing cells in the small intestine

• ex. Crohn’s disease

Lactose intolerance treatment

-up to 12g of milk at one time

-small amounts at a time

-yogurt and hard cheeses are low in lactose

-lactase products

Two parts of the body that regulate blood glucose

Liver and pancreas

What hormones does the pancreas secrete

insulin and glucagon

What hormone(s) decrease blood glucose levels

Insulin

What hormone(s) increase blood glucose levels

glucagon, epinephrine, norepinephrine, cortisol

Type 1 diabetes cause, risk factors, characteristics and treatment

-Autoimmune attack on the pancreas

-moderate genetic predisposition

-thirst, hunger, urination

-insulin

Type 2 diabetes cause, risk factors, characteristics and treatment

-More common (90% of cases)

-insulin resistance (pancreas still making insulin, cells don’t want insulin)

-strong genetic predisposition

-mild symptoms

-diet and exercise

Long-term complications of diabetes

cardiovascular disease

retinopathy- blindness

nephropathy- kidney disease

neuropathy- nerve damage

What is metabolic syndrome

cluster of health factors, diagnosed when 3 or more of the following criteria are present

large waist circumference

hypertension

elevated fasting blood fats

low HDL cholesterol

high blood glucose

3 groups in the diabetes prevention program

intensive lifestyle change group

metformin group

placebo group

Diabetes prevention program outcomes

after 3 years

• lowered chances of type 2 diabetes by 58%

after 10 years

• decreased by 34%

after 15 years

• decreased by 27%

RDA for carbs

130 g/day

AMDR for carbs

45-65% of total kcal intake

AI for dietary fiber

25 g/day for women

38 g/day for men

DGA for added sugars

10% of total daily energy intake

Lipids composed of

CHO

Are lipids soluble in water?

No

Diglyceride meaning

Triglyceride that lost 1 fatty acide

Monoglyceride meaning

Triglyceride that lost 2 fatty acids

Hydrolysis definition

The reaction that releases fatty acids from glycerol

water is used

Condensation definition

The reaction that adds fatty acids to glycerol

Re-esterification definition

Process of reattaching a fatty acid to glycerol

Triglyceride structure

3 fatty acids attached to a 3-C glycerol backbone

How do fatty acids vary

number of carbons in the chain

degree of saturation

shape of chain

How many carbons are long-chain fatty acids and where are they found?

12+

beef, pork, plant oils

How many carbons are medium-chain fatty acids and where are they found?

6-12

coconut oil, palm oil, milk fat (butter)

How many carbons are short-chain fatty acids and where are they found?

<6

3% of fat in butter

Structure of a saturated fatty acid

all between carbon-carbon single bonds

saturated with hydrogen

Monounsaturated fatty acid structure and where they are found

one double bond in the chain

olive oil, almonds, peanuts

Polyunsaturated fatty acid structure, and where they are found

more than one double bond

sunflower oil, corn oil, safflower oil, fish oil

Shape of unsaturated fatty acids

bent

What does hydrogenation do?

adds hydrogen to the carbon chain of an unsaturated fatty acid

chain becomes saturated, straight, solid at room temperature

Omega-3 fatty acid structure

first double bond is between 3rd and 4th carob from the methyl group

Omega 6 fatty acid structure

first double bond is between the 6th and 7th carbon from the methyl carbon

name for omega 3

alpha-linolenic acid

name for omega 6

linoleic acid

Which fatty acids are solid at room temperature and associated with an increased risk of chronic disease

saturated

Which fatty acids are liquid at room temperature and associated with an decreased risk of chronic disease

unsaturated

Omega 3 turns into what?

Eicosapentanoic acid (EPA)

Docosahexanoic acid (DHA)

food sources for alpha-linolenic acid

walnuts, flaxseeds, hemp oil, canola oil, soybean oil, chia seeds

food sources for EPA and DHA

cold-water fish (salmon, tuna, halibut, sardines, mackerel)

where is cholesterol found

exclusively in foods of animal origin

Functions of triglycerides

concentrated and compact energy source

insulate and cushion organs

enable absorption/transport of some nutrients

linoleic acid turns into what

arachidonic acid

alpha-linolenic acid and linoleic acid are precursors to eicosanoids. what are eicosanoids?

substances that produce diverse hormone-like effects on the body

structure of phospholipids

glycerol backbone

2 fatty acids

phosphate group

What part of the phospholipid is hydrophilic? hydrophobic?

hydrophilic-head

hydrophobic-tail

Functions of phospholipids

cell-membrane component

emulsifier

Cholesterol is used to make what

sex hormones

active form of vitamin D

bile

cell membranes

cortisone

shell-covering chylomicrons

enzyme that breaks down lipids in the mouth and what it breaks down

lingual lipase

short and medium chain fatty acids

enzyme that breaks down lipids in the stomach and what it breaks down

gastric lipase

triglycerides to diglycerides and free fatty acids

The presence of lipids triggers what hormone in the small intestine

CCK

What does CCK do?

triggers the release of bile and pancreatic lipase

bile emulsifies fat

pancreatic lipase breaks down triglycerides to monoglycerides and free fatty acids

micelles are formed

What are lipoproteins used for

the hydrophobic nature of lipids requires use of transporter within the blood

what does LPL stand for

lipoprotein lipase

what does LPL do

hydrolyzes circulating triglycerides from chylomicrons and VLDL to free fatty acids and glycerol