Intersection 5

10/3/05

Reading: 9.6 p409 – 418;

3.12 p111-113

Material for this lecture taken from Laursen, S; Mernitz, H.  Would You Like Fries with That? The Fuss About Fats in our Diet; Wiley & Sons:  New York , 2000.

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A Gateway to Information Storage and ExpressionHow does nature store and express information?

How does nature’s way compare to our computers and hard drives?What is the impact of this understanding and resulting technologies?

Special Guest: Dr. David Burke (UM Human Genetics Department)

6 – 7:30 PM Monday October 9th

Room 1230 USB

Please RSVP by email to Prof Banaszak Holl(mbanasza@umich.edu)

Gateway evenings are optionaland will not affect your course grade

Gateway Chemistry 130/125/126Section 600

Dinner Provided

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Outline

• Bond length • Molecular polarity• Intermolecular Forces

– The trio of forces

– Olestra

– Vitamins

– Macronutrients and diet• Betacarotene

• Vitamin D in OJ

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Bond Order

• Single bond - first order

• Double bond = second order

• Triple bond third order

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s orbitals

s + p orbitals

s + p + p orbitals

Bond Length (pm): the distance between the nuclei of two bonded atom

H-F 92 C=C 134 C-O 143

H-Cl 127 C=N 127 C=O 122

H-Br 142 C=O 122 C≡O 113

H-I 161

C-C 154

C-Si 194 C-C 154 C=C 134

C-P 187 C-N 147 C≡C 121

C-S 181 C-O 143

C-Cl 176 C-F 141

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Polarity of Molecules: Maps of Electron Density

+ -

Br

FF

F

FF

C

H

ClCl

Cl

BrF5

CHCl3

A

SCN-

S C N

-1

S C N

-1

A

Is it SO2 or H2O?

H

O

H

A

S

O O

+1

-1S

OO

+1

-1

Molecular Polarity

• NO2-

• ClF3

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Intermolecular Forces

1) Why do we have to take some vitamins everyday (B and C), while our body stores others well?

2) Why are vitamins A, D, E, and K added to any products containing Olestra?

Picture from: http://enquirer.com/editions/2000/06/23/oleanproducts.jpg

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O

O

Vitamin K

CH3

H

CH2

HO

CH3CH3

CH3

Vitamin D

OH3C

HO

CH3

CH3

CH3

CH3CH3

CH3

CH3

Vitamin E

H3C CH3

CH3

CH3 CH3

OH

Vitamin A

N

N

N+

SH3C

NH2 CH3

OH

Vitamin B1

O O

OHHO

HO

HO

H

Vitamin C

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OlestraOlestra is a fat substitute developed by Proctor and Gamble and

used to make Ruffles WOW! Potato chips.

Serving Size 1 oz (28 g/ about 17 chips)

Total fat 0 g (Original Ruffles 10 g)Total Calories 75 (Original Ruffles 160)

Ingredients: potatoes, olestra (Olean® brand), salt, alpha-tocopheryl acetate (vitamin E), vitamin A palmitate, tocopherols (to protect flavor), vitamin K, and vitamin D.

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Hypothesis1) Why do we have to take some vitamins

everyday (B and C), while our body stores others well?

2) Why are vitamins A, D, E, and K added to any products containing Olestra?

• What is your hypothesis?

• How would you test it?

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Testing the HypothesisStep 1: Separate

– Vitamins added to test tube with water and ligroin and shaken…which layer is on top? How do you know?

Ligroin - a complex mixture which includes

H3C

H2C

CH2

H2C

CH2

H2C

CH3

H3C

H2C

CH2

H2C

CH2

H2C

CH2

CH3

H2C

H2CCH2

CH2

CH2

H2C

CH3CH2H3C

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Spectroscopy

Step 2: TestMolecules (containing double bonds) typically absorb

light in the UV region of the spectrum. Water and ligroin do not absorb light in the same region of the UV spectrum.

Shine UV light through the water layer or the “oil” layer sample to a detector

Measure the intensity of the light going into the sample and the intensity of the light coming out.

Determine if sample absorbed light

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RetinolCartenoids such as betacarotene converted to retinol

Vision bone growth, cell division and differentiation

Eggs, milk, liver, fortified cerealsCarrots, cantaloupe, sweet potatoes, and spinach

H3C CH3

CH3

CH3 CH3

OH

Vitamin A

A

Vitamin A

-0.5

0

0.5

1

1.5

2

2.5

250 300 350 400 450 500 550 600

Wavelength (nm)

Abso

rban

celigroin

water

A

Vitamin B1

Thiamine

Nervous systems, muscles, heart

Kidney, liver, flour, beans, pork, salmon, soybeans, wheat germ

N

N

N+

SH3C

NH2 CH3

OH

Vitamin B1

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Vitamin B1

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

250 300 350 400 450 500 550 600

Wavelength (nm)

Absorb

ance

ligroin

water

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Vitamin C

Ascorbic acid

Anti-oxidant, free-radical scavenger

Pepper, citrus, tomatoes, melons, broccoli, green leafy veggies

O O

OHHO

HO

HO

H

Vitamin C

A

Vitamin C

-0.5

0

0.5

1

1.5

2

2.5

250 300 350 400 450 500 550 600

Wavelength (nm)

Absorb

ance

ligroin

water

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Vitamin D

Group of steroids called cholecalciferol

Regulate calcium, phosphorous, bone mineralization

Enough sun and don’t need supplement; found in egg yolk and fish oil, fortified food products

CH3

H

CH2

HO

CH3CH3

CH3

Vitamin D

A

Reported soluble in ligroin

Vitamin E

Alpha-tocopherol

Antioxidant

Vegetable oils, nuts, green leafy veggies, fortified cereals

OH3C

HO

CH3

CH3

CH3

CH3CH3

CH3

CH3

Vitamin E

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Vitamin E

-0.5

0

0.5

1

1.5

2

2.5

250 300 350 400 450 500 550 600

Wavelength (nm)

Absorb

ance

ligroin

water

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Vitamin K

Synthesis of proteins that regulate coagulation and anticoagulation

Leafy greens, cauliflower, liverSynthesized by bacteria in large intestine

O

O

Vitamin K

A

Vitamin K

-0.5

0

0.5

1

1.5

2

2.5

250 300 350 400 450 500 550 600

Wavelength (nm)

Absorb

ance

ligroin

water

A

O

O

Vitamin K

CH3

H

CH2

HO

CH3CH3

CH3

Vitamin D

OH3C

HO

CH3

CH3

CH3

CH3CH3

CH3

CH3

Vitamin E

H3C CH3

CH3

CH3 CH3

OH

Vitamin A

N

N

N+

SH3C

NH2 CH3

OH

Vitamin B1

O O

OHHO

HO

HO

H

Vitamin C

A

Water soluble (hydrophilic)

Fat soluble (hydrophobic)

1) Why do we have to take some vitamins everyday (B and C), while our body stores others well?

2) Why are vitamins A, D, E, and K added to any products containing Olestra?

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ROO

C

CC

H

H

RO

H

O

ORH

CH2

HC

C

OR

C C

C

O

C

HOR

OR

H

CH2

CH2

H

RO

OR

R = C

O

CH2

H2C

CH2

H2C

CH2

H2C

CH2

HC CH

CH2

H2C

CH2

H2C

CH2

H2C

CH2

CH3O

H2C

HC

H2C

O

O

C

O

CH2

H2C

CH2

H2C

CH2

H2C

CH2

HC CH

CH2

H2C

CH2

H2C

CH2

H2C

CH2

CH3

C

O

CH2

H2C

CH2

H2C

CH2

H2C

CH2

HC CH

CH2

H2C

CH2

H2C

CH2

H2C

CH2

CH3

C

O

CH2

H2C

CH2

H2C

CH2

H2C

CH2

HC CH

CH2

H2C

CH2

H2C

CH2

H2C

CH2

CH3

HOO

C

CC

H

H

HO

H

O

OHH

CH2

HC

C

OH

C C

C

O

C

HOH

OH

H

CH2

CH2

H

HO

OH

Sucrose, sugar

Fat

Olestra

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From Olean ® WebsiteIn January 1996, the FDA approved the use of olestra in salty

snacks; Olean has been on the market since 1998 (Frito Lay and Pringles)

First FDA approved fat replacer that doesn’t “break down” at high temperatures

Hundreds of clinical tests have validated the safety of olestra

“One of the most studied food ingredients EVER.” “30 years of testing and research” ”Many medical doctors and culinary experts support the use of olestra-based products”

More than 3 billion servings (210 million lbs of chips or 70 million lbs of olestra) have been consumed by Americans.

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www.olean.com (accessed October 2006)

Theater Test• 1,092 people, aged 13-88, watched a movie and

ate up to 13 oz of chips (Olestra or TG)

• Median consumption of Olestra (60g vs 77 g) lower and taste lower (5.6 vs 6.4) on 9 point scale

• No difference in GI symptoms– TG 93 of 529 (17.6%)– Olestra 89 of 563 (15.8%)

• Funded by P&G

JAMA 1998, 279, 150-153.

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Center for Science in the Public Interest

• Procter & Gamble's own studies prove olestra causes diarrhea, cramps, and other symptoms.

• FDA has more than 20,000 complaints about olestra in its files--more than it has for all other food additives in history combined.

• “Olestra may cause loose stools and abdominal cramping” printed on package

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www.cspinet.org/ (accessed October 2006)

Vitamin Concerns

Procter & Gamble's eight-week clinical studies: – 8 gm/day (~16 olestra-containing potato chips) blood

serem carotenoids, alpha-carotene, beta-carotene, lutein, and lycopene levels were down by 50% to 60% by the end of the studies

– 32 gm/day of olestra reduced total serum levels by 70%

Vitamin K is really important: – Drug efficacy of anticoagulant Coumadin (1.5 million)

sensitive to fluctuations in vitamin K levels. – bone formation in fetal development and childhood and

retention of bone in older women linked to vitamin K

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www.cspinet.org/ (accessed October 2006)

Olestra’s Fate

• Sales of chips declined by 60%

• Approval not sought for other uses

• P&G sold the factory

In the body, vitamin D is concentrated in the skin, liver, and kidneys. Vitamin A is found in the liver and kidneys and in membranes such as the mucus membranes and the retina of the eye. Excess vitamin A accumulates in the liver, and excess vitamin D in the kidneys.

What can you infer from these facts about the fat content of these tissues?

Question 3

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Why are deficiencies of vitamin D, E, and K rare, but deficiencies in vitamins C and B much more common?

Question 4

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How can we increase Vitamin absorption in the body?

• "In 1958, Roels and coworkers studied a group of Rwandan schoolboys who had low vitamin A levels in their blood. They divided the boys into three groups. One group ate 200g of carrots per day,[1] containing about 25 mg of beta-carotene, a compound that is equivalent to vitamin A in the body. A second group of boys received 20 mL of olive oil along with the same amount, 200g, of carrots. The third group of boys at no carrots but were given 28 mg beta-carotene dissolved directly in the olive oil."3

•[1] From Laursen, S; Mernitz, H.  Would You Like Fries with That? The Fuss About Fats in our Diet; Wiley & Sons:  New York , 2000. The study is from Roels, O. A.; Trout, M.; et. al. "Carotene Balances in Boys in Rwanda Where Vitamin A Deficincy is Prevalent," J Nutr. 1958, 65, 115-218.

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The following graph shows the blood plasma level of carotenes, the family of compounds related to beta-carotene, in micromoles carotene per liter of plasma vs. time.

Figure from: http://www.hsph.harvard.edu/Academics/nutr/olestra/fig6.html

What can you conclude from the graph?

0

2

4

6

8

10

12

Pla

sm

a C

aro

ten

es

(u

M)

0 5 12 19 26 31

Days of Dietary Supplement

Interaction of dietary beta-carotene and vegetable oil

200 gms carrots/day

carrots + 20 mL olive oil

28 mg beta-carotene + olive oil

Data from Roels, Trout, and Dejacquier, 1958

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Questions 5-65) Suggest some reasons why the beta-carotene dose

may have been more effective in raising blood plasma levels of carotene than the carrots, even when both were given with olive oil. Does that mean that beta-carotene supplements are better for you than carrots? Why or why not ?

6) Why do blood carotene levels seem to level out after a few days of dosage?

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Note

Similar experiments have shown that other carotenoids (plant-derived nutrients with chemical structures similar to carotene) are also absorbed better in the presence of oil. Other experiments show, moreover that the oil must be digestible. When indigestible (but safe to eat) mineral oil is given with the carotene, blood carotene levels do not rise.

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The Trio of Intermolecular Interactions

I. London Dispersion Forces– All molecules – Related to the polarizability of a molecule or

how distortable the molecule’s molecular orbital is.

– Larger = more easily distorted

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Question 7

Explain this trend: Boiling

point (oC)

CH4 -164

CH3CH3 -89

CH3CH2CH3 -42

C5H12 36

C6H14 69

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II. Dipole-dipole

Molecules that have dipoles interact

CCl

Cl

Cl

H

+CCl

Cl

Cl

H

+

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Question 8

Acetone and chlorine both have the same molecular weight. Acetone boils at about 58 °C, whereas chlorine boils at –34 °C.  Explain why there is such a large difference in their boiling points.

Acetone has the following structure: O

CC

H

HH

CH

HH

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III. Hydrogen Bonding

• Especially strong dipole-dipole

• N-H, O-H, F-H

• Intermolecular (dashed lines)

H F+ -

H F+ -

H

F

+

-

H F+ -

Picture from: http://www.elmhurst.edu/~chm/vchembook/images/122hbondwater.JPEG

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Question 9

Hydrogen bonding can also occur between different kinds of molecules. For example, an ammonia (NH3) molecule and a water (H2O) molecule. Draw ammonia and water, and any hydrogen bonding that could occur between them.

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Reference Sources

Primary sources are, “original, first-hand documents” 1

Examples: journal articles; research reports

Secondary sources are, “works that interpret or analyze the content of the primary sources.”2

Examples: Reference books, text books, scholarly publications, encyclopedias

1 http://www.lib.umich.edu/ugl/classes/eval/

2 http://www.lib.umich.edu/ugl/guides/assist/assignments/primarysources.html

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Wikipedia• Dynamic• Current• Good overview or starting place• No peer review• Anyone can change anything

“As with any source, especially those of unknown authorship, you should be wary and independently verify the accuracy of Wikipedia information if possible”1

1http://en.wikipedia.org/wiki/Wikipedia:Citing_Wikipedia

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The Internet

• Useful for pointing to primary sources

• Evaluate each web page for its sources

• Use the library resources. These will point you to a variety of edited databases.

• http://searchtools.lib.umich.edu

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Exam

• 8:00 pm TONIGHT in CHEM 1400

• Ethics of exam taking

• Regrades (by Friday, October 13th)

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