Unit Iv Food

UNIT IV – FOOD

SECTION A: Introduction to Foods:  What in the world does Food have to do with Chemistry?  Food is a fuel, like petroleum, full of POTENTIAL CHEMICAL ENERGY  What NUTRIENTS are required by our bodies for survival? 1. Protein 2. Fat 3. Carbohydrates 4. Minerals 5. Vitamins 6. Water  What are some examples of some foods that are rich in each of the above nutrients? 1. Protein - 2. Fat - 3. Carbohydrates - 4. Minerals - 5. Vitamins - 6. Water -  Different cultures have different sources of the same primary nutrients required for survival…can you think of some?  Eastern Indian :  Hispanic :  Korean :  Vietnamese :  African :  Italian :  German :  “American” :  What is the FDA?  Food and Drug Administration

 What is the RDA?  Recommended Dietary Allowance  Based on 2,000 or 2,500 Cal/day diet

 The Food Pyramid  Guide to the amounts and types of foods we SHOULD be eating every day

 What IS a “serving”?  cup, Tsp. Tbsp, grams, ounces etc. – depends, be careful! One serving of peanuts will not be the same size as one serving of carrots

 Is malnutrition the same as undernourishment? If not, how are they different? Is it caused by circumstance, disease, choice, or being ill- informed?  MALNOURISHMENT – not having the correct amounts of all of the nutrients we need  UNDERNOURISHMENT – not having enough of the nutrients we need UNIT IV B – FOOD ENERGY

SECTION B.1 – Lab: Food Energy in a Peanut

SECTION B.2 – Food and Energy  The Calorie  An energy “unit” 1 Calorie = 1Kilocalorie = 1000 calories  Dietary energy measured in Calories  1 calorie = amount of Energy required to raise 1 g of water 1C 1  1 Kilocalorie = amount of Energy required to raise 1 Kg of water 1C

To calculate Energy : calories = ___g H20 x T

 Sample Problem: 3 teaspoons of sugar (12 g) are burned and are able to

heat 860 g H2O from 22C to 85C. 1.) How much energy was contained in the three teaspoons of sugar? 2.) How many food Calories are contained in the three teaspoons of sugar? 3.) How many food Calories are contained in 1 teaspoon of sugar?

 Food Energy Conversion  PHOTOSYNTHESIS: provides energy from sun to make complex molecules out of simpler molecules

6CO2 + 6H2O C6H12O6 + 6O2

 We get all of the energy that keeps us alive from the sun!

 METABOLISM: breaking down complex molecules to yield energy

C6H12O6 + 6O2 6CO2 + 6H2O

 We have a SYMBIOTIC relationship with plants!! SECTION B.4: Fats  What do we NEED fat for anyway? ( TEC–V-TEN )  T  Energy  Cell Membranes  Vital organ protection  Thermal  E  Neural development

 Pound for Pound, FAT is the most efficient way your body stores energy  1 gram FAT = 9 Cal.  1 gram CARBOHYDRATE = 4 Cal.  1 gram PROTEIN = 4 Cal.

 What are FATS?  Fats are made of only 3 elements : C,H, and O  Fats are LIPIDS (therefore NOT water soluble) - also called TRIGLYCERIDES (Fancy names for Fats!)  EXAMPLES: Butter, Lard, Oils  FATS are made by FATTY ACIDS getting together with GLYCEROL

H C O C (CH ) H 2 14 CH3 O H C OH O H C O C (CH2)14 H C OH 3 HO C (CH2)14 CH3 CH3 H2O O H C OH H C O C (CH ) CH H 2 14 3 H GLYGEROL PALMITIC ACID GLYCEROL TRIPALMITATE WATER

FORMATION OF A TRIGLYGERIDE (FAT)  Fats can be SATURATED  Having as many H’s as possible (therefore no double bonds between carbons)  Generally SOLIDS at room temperature  Bad for your Body – blocked arteries

H H H H H H H H H H H H H H H O H C C C C C C C C C C C C C C C C OH H H H H H H H H H H H H H H H

PALMITIC ACID A SATURATED FATTY ACID

 Fats can be UNSATURATED  Having at least one double bond  Generally LIQUIDS at room temperature  Generally reactive within the body (due to double bonds)

 Can be MONOUNSATURATED – one double bond between carbons

H H H H H H H H H H H H H H H H H O

H C C C C C C C C C C C C C C C C C C OH H H H H H H H H H H H H H H H

OLEIC ACID A MONOUNSATURATED FATTY ACID

 Can be POLYUNSATURATED – multiple double bonds between carbons

H H H H H H H H H H H O

H C C C C C C C C C C C C C C C C C C OH H H H H H H H H H H H H H H H H H

LINOLENIC ACID A POLYUNSATURATED FATTY ACID  PARTIALLY HYDROGENATED FATS– really means synthetically adding more H’s to Fat molecules – makes them more SATURATED and therefore

less healthy – literally- they shake up UNSATURATED fats with H2 gas  Cis-FATTY ACIDS – mostly found in nature – means “SAME SIDE”

H H H O H C C C C OH H CIS-FATTY ACID

 Trans-FATTY ACIDS – made in lab by PARTIAL HYDROGENATION – means “OPPOSITE SIDE”

H H O H C C C C OH H H TRANS-FATTY ACID

 Found to increase LDL Levels (LOW DENSITY LIPOPROTEINS) – these are bad  Found to decrease HDL Levels (HIGH DENSITY LIPOPROTEINS) – these are good  Poor LDL to HDL ratio Amounts to HIGH CHOLESTEROL!!

 Americans get 40% of Calories from fats, on average  RDA for Calories from Fat = 30%  RDA for Calories from Saturated Fat = 10% or less

 1.2 Million $$ QUESTION: Can you still “get fat” even if you don’t eat any fats? SECTION B.5: CARBOHYDRATES  What are CARBOHYDRATES?  Just like Fats in that they contain only 3 elements: C, H, and O  Sources of “Quick Energy” for your body - Sugars and Starches  Examples: Fruits, Vegetables, Breads  60 % of total dietary Calories should come from Carbohydrates

 Can be MONOSACCHARIDES – generally 5 or 6 C’s form backbone – can be straight chain or a ring

OH OH OH H OH O HO CH2

H C C C C C C H O OH H H H OH H OH GLUCOSE OH OH

GLUCOSE

 Glucose (blood sugar)  Fructose (fruit sugar)  Galactose

HO CH HO CH2 2 HOCH2 OH O O H O OH OH HO OH OH CH2OH OH OH OH OH FRUCTOSE OH GLUCOSE GALACTOSE  Can be DISACCHARIDES – 2 MONOSACCHARIDES joined together  Sucrose (cane sugar) = Fructose + Glucose  Lactose (milk sugar) = Galactose + Glucose  Maltose (malt sugar) = Glucose + Glucose

HO CH2 HOCH2 O O H OH OH O CH2OH OH OH OH SUCROSE

 Can be POLYSACCHARIDES – SACCHARIDE polymers  Starch - Long chains of saccharides in foods  Glycogen – Long chains of saccharides your body uses to store energy  Cellulose – Long chains of saccharides your body can not break down

HO CH2 HO CH2 HO CH2 HO CH2 HO CH 2 H O O H O H O H O H H H HO CH2 H O OH OH OH OH O O O OH H O O O H O OH H OH O OH H OH OH OH OH STARCH OH CELLULOSE

 DISACCHARIDES and POLYSACCHARIDES formed by CONDENSATION reactions between SACCHARIDE molecules HO CH2 HO CH HOCH 2 HOCH O 2 O 2 H O O OH H OH HO OH OH CH2OH H2O OH O CH2OH OH OH OH OH OH OH GLUCOSE FRUCTOSE SUCROSE WATER FOODS UNIT SECTION C – PROTEINS AND LIMITING REACTIONS

C.1 – FOODS AS CHEMICAL REACTANTS  METABOLISM – series of chemical reactions in the body that breaks down nutrients in order to extract energy from them

C.2 – LIMITING REACTANTS  Every recipe requires a complete set of ingredients – whether we are talking about the recipe for a cake, or the recipe for making an enzyme, hormone, muscle etc.  The ingredient that runs out first is called the LIMITING REACTANT in an equation.  The LIMITING REACTANT is the most important ingredient because it determines how much product can be made.  Every recipe can be represented in the form of an equation….

Mamma Hutson’s not-so-famous Saturday Sandwich:

2 slices bread 3 slices turkey 1 Tbsp. Mayo 4 slices bacon 1 slice cheese

2 bread + 4 bacon + 3 turkey + 1 cheese + 1 mayo 1 sandwich

 Say we are expecting 20 people over on Saturday….how can I figure out how much bacon I need to buy?

 Say I get home from the store with 1 loaf (20 slices) of bread, 10 slices of cheese, 30 slices bacon, and 15 slices of turkey…. Which ingredient limits the amount of sandwiches I can make? (assume an infinite amount of mayo)  One last deli problem to think about…. They don’t always sell things at the deli by number, often it is by the pound. If I get home with 2 lbs of bread, 1 lb of cheese, 1 lb of bacon, and 2 lbs of turkey,…. How can I figure out what is the limiting reactant from my recipe now?!

Conversion Factors: 1 slice bacon = 0.12 lb 1 slice turkey = 0.09lb 1 slice cheese = 0.15 lb 1 slice bread = 0.10 lb

LIMITING CONCEPT APPLIED TO CHEMISTRY RECIPES…

Your body’s recipe for getting energy out of glucose:

C6H12O6 + 6O2 6CO2 + 6H2O + Energy

 Say you have 20 glucose molecules and 100 oxygen molecules Which one will run out first?

 How many molecules of CO2 can be produced?  Say you have 100 grams of glucose and 100 grams of oxygen Which one will run out first?

 How many molecules of CO2 can be produced?

STEPS TO SOLVING LIMITING REACANT PROBLEMS

1. Check to see that the overall equation is balanced – if not, balance it first 2. If amounts of reactants are given to you in grams – use the gram formula masses from the periodic table to convert from grams to moles 3. Find out which reactant is limiting  choose ONE reactant  use the number of moles of the chosen reactant and the recipe from the balanced equation to determine how much of the other reactant is need  if you determine that the amount of other reactant needed is more than what is given to you – then it is the LIMITING REACTANT  if you determine that the amount of other reactant needed is less than what is provided to you – then it is the EXCESS REACTANT 4. Use the moles of reactant you found to be limiting and the recipe from the balanced equation to determine the number of moles of product that can be made 5. If the question asks for the number of grams of product that can be made – use the gram formula mass from the periodic table to convert from moles back to grams 6. If the question asks how much of the excess reactant is left over – subtract the number of moles of reactant used from the original amount given

Remember that the coefficients can stand for molecules (on the small scale) or moles (large scale)  Sample Limiting Problem: sodium metal get together with chlorine gas to form table salt. I have15 grams of sodium, and 26 grams of chlorine. Which is the limiting reactant? How much sodium chloride can be made (grams)? How much of the excess reactant will be left over?

1. Na + Cl2 NaCl

2. 2Na + Cl2 2NaCl

6. C.3 – PROTEINS  Proteins make up many body tissues : skin, hair, nails, tendons, muscle, enzymes, hormones etc. etc.

 INSERT Table6 pg. 263

 PROTEINS are essentially POLYMERS made up of AMINO ACID subunits  AMINO ACIDS  There are only 20 of them – and they combine in different arrangements to make up all of the millions of different proteins in your body!  All amino acids are composed of : C, H, O, N….. some also have S  All amino acids contain the same two functional groups:

 AMINE : C –(NH2)  ORGANIC ACID: C-(COOH )  Amino acids bond together via a condensation reaction (imagine that!) to form PEPTIDE BONDS:

Insert figure 12 pg. 264  ENZYMES : special class of proteins that act as catalysts in your body.  Catalyst : something that helps speed up the rate of a reaction without actually being changed itself….  Enzymes work by being the correct shape to fit particular molecules – often referred to as “lock and key” model  Enzymes work by being the matchmaker - getting two molecules together

 Can tell something is an enzyme by the name: the ending is “ase”  i.e. – alcohol dehydrogenase - this one helps break apart alcohol into hydrogen and acetaldehyde (in the same family as formaldehyde… wonder why people feel pickled when they drink too much?!)

DIETARY PROTEIN  Your body breaks down protein in the diet into amino acids and reforms the new proteins it needs  Your body can make 11 of the 20 amino acids - it can not make the other 9  ESSENTIAL AMINO ACIDS - the 9 amino acids you MUST get from you diet  A protein that provides all of the essential amino acids is called a COMPLETE PROTEIN – this is most animal proteins – but plant proteins are not complete proteins - poses a problem for vegetarians – or folks without a lot of meat in their diet  COMPLEMENTARY PROTEINS – combination of foods that together contain all of the essential amino acids

FOOD COUNTRY Corn tortillas and dried beans Mexico Rice and black-eyed peas US Peanut butter and bread US Rice and bean curd China and Japan Rice and lentils India Wheat pasta and cheese Italy FOODS Section D Vitamins, Minerals, and Additives

D.1 – VITAMINS  VITAMINS – biomolecules required in very small amounts to aid in various specific biochemical processes

 Water-soluble vitamins: i.e. B1, B12, C,…. o get excreted in urine o must be continually replenished o can be degraded by cooking  Fat-soluble vitamins: i.e. A, D, E, K(this is not potassium!!) o stored in fat reserves o can build up to toxic levels  See Table 9 for specific vitamin sources and deficiency conditions

D.2 – LAB: VITAMIN C DETERMINATION  Titration – using a certain volume of a solution of known concentration to determine the amount of something in an unknown solution.  Endpoint - the point where all of a particular substance is used up – generally signaled by a color change

+ - I2 + C6H8O6 C6H6O6 + 2H + 2I

D.3 – MINERALS  MINERALS – elements required for human life – there are 22 known required - Examples: Ca, Na, K, I, Fe etc….  See Table 12 for a list of minerals and uses

D.4 – LAB: DETERMINING THE AMOUNT OF IRON IN FOODS

D.5 – FOOD ADDITIVES  Non-nutrients added to foods to increase appeal, flavor, shelf-life, etc. Examples: benzoic acid, aspartame, dyes, MSG,….  See Table 14 for a list of some food additives SECTION D - VITAMINS, MINERALS, AND FOOD ADDITIVES

Name______Date______Period___ SECTION D.1 – VITAMINS – Read pgs. 270-273 1) Provide two food sources for each of the following Vitamins: Vitamin A ______, ______Vitamin K ______, ______Vitamin E ______, ______Vitamin D ______, ______Vitamin C ______, ______Folic Acid ______, ______Thiamin ______, ______Niacin ______, ______

2) Fill out the following table for each of the Vitamins provided : Vitamin What’s it good for? Deficiency Condition / Description A D E K C Thiamin Niacin

SECTION D.3 – MINERALS – Read pgs. 275-277

1) What is the difference between vitamins and minerals? 2) Provide the missing information in the table provided below: Mineral What’s it good for? Deficiency Condition / Description Ca K Mg Na I F Fe Zn Ni

SECTION D.5 – FOOD ADDITIVES – Read pgs. 279-280 & pgs. 284-287

1) What are Food Additives and why do we add them to our foods?

2) Provide 2 examples of food additives and what purpose each of them serve:

3) What types of contaminants might we find in our processed foods?

4) What is the Delaney Clause?

5) What is a phenylketonuric?