chem 1003 the chemistry of food, health and drugs midterm review questions

CHEM 1003

THE CHEMISTRY OF FOOD, HEALTH AND DRUGS

Midterm review Questions

Calorie counting

A handful of peanuts contains ~15 grams of carb., 4 grams of protein and 8 grams of fat. While watching the Stanley Cup final, you consume 10 handfuls of peanuts, and 1.0 liter (~3 cans) of Labatts “Blue light” (4% alcohol). Assuming all of the calories in the beer come from alcohol, what is your total caloric intake?

Assume the density of beer is 1 gram/cm3.

Quite a few!!

Cheering hard will help burn some off!

Bring your calculator to the midterm Recall, carbs and protein are 4 Cal/gram, fat is

9 Cal/gram and alcohol is 7 Cal/gram. From the peanuts: each handful (15+4)x

4=76Cal from carbs and protein. From fat 8x9=72Cal.

So 76+72=148 per handful x10= 1480 Cal From the beer, # grams of alcohol in 1 L= .04

x 1000=40, so Calories from alcohol =7X40=280

Total caloric intake= 1480 +280= 1760Calories!

Having consumed alcohol, you decide to walk home (wise move!) Assuming you work off 200 Cal per hour

walking and it takes you 30 minutes to walk home, what% of your intake have you burned off?

Not so much!!!!!!!

Fraction burned off =100/1760 or .057% burned off =.057 x100=5.7%

Multiple Choice

1 mark each

In hemoglobin, iron is in the following valence state Neutral +2 +3 +4 +6

Probiotic yogurt

Often contains Lactobacillus acidophilus bacteria

Boosts the bacterial content of the large intestine

Can act as a booster to the immune system

Promotes regularity All of the above

The compound given off by ripening fruit is Polyethylene Acetylene Propylene Ethylene Butene

Evening Primrose oil and Corn oil are classified as supplements contain high amounts of polyunsaturated

fatty acids Cost about the same per unit volume Have high glycemic indices Are potent antioxidants

Apples, oranges and onions have the following common property They have high vitamin C content They have substantial amounts of

soluble fibre They are good for the common cold They are cruciferous They are all grown in Canada

Soluble fibre is mainly

Cellulose Amylopectin Amylose Pectin Polygalactose

The 2nd most abundant element in bones is Calcium Carbon Iron Phosphorus Magnesium

The 2 chemicals necessary for photosynthesis are Oxygen and water Oxygen and carbon dioxide Water and carbon dioxide Oxygen and carbon Carbon and hydrogen

All steroids are

Hydrocarbons Anabolic Natural products Growth hormones Composed of a 6,6,6,5 ring structure

The chemical formula of glucose is C12H6O6

C6H12O6

C6H6O12

C6H6O6

C12H22O11

The chemical formula of sucrose is C6H6O12

C12H6O6

C12H22O11

C12H24O11

C6H12O6

The most “heart healthy” way to consume alcohol is Beer White wine Red wine Whisky All of the above

Vitamin needed to prevent Scurvy is A B C D E

Which vitamin is not fat soluble A E K D All are fat soluble

Radiation most likely to cause skin cancer is IR Microwave Visible light Short wavelength UV Long wavelength UV

The chemical with the longest history of use as a preservative is Sodium nitrate Ascorbic acid Sodium iodide Sucrose Sodium chloride

Nitrites added to processed meats present a specific risk of Botulism Goiter Kidney failure Cancer Cardiovascular disease

Sucralose is

An aspartame derivative A source 4 Cal per gram A monosaccharide An enzyme that permits metabolism of

sucrose Trichlorosucrose

A compound whose name ends in –ase is usually A protein A carbohydrate An enzyme An essential amino acid A trace mineral

Metabolism of aspartame produces small amounts of Methane Ethanol Ascorbic acid Ethane Methanol

Chemically, aspartame is

A disaccharide An aspartic acid ethyl ester A polyester of sucrose A dipeptide derivative A Saccharin derivative

An element needed for normal functioning of the thyroid gland is Bromine Chlorine Fluorine Iodine astatine

A useful description of junk food is that it Appeals to children Is sweet Lacks essential amino acids Provides incomplete protein Provides a large number of calories and

only a few micronutrients

Too much sodium in the diet is a major cause of Goiter High cholesterol Low LDL levels Diabetes High blood pressure

Question #1

Virtually all of the chemical energy that we derive from consumer goods such as gasoline, heating oil and food is stored in their: a)nuclei

b)chemical bonds

c)protons

d)electrons

e)ions

The compound C2H2 is

Ethylene Butene Ethyne Propene Propylene

An example of an ester is

Glycerol Pentane Methyl ethyl ketone A triglyceride Stearic acid

The brain’s exclusive source of energy is Glycogen Sucrose Lactose Maltose Glucose

Question #2

For a healthy adult, basal metabolism amounts to:

a) about half the daily calorie expenditure

b) twice the amount of energy spent in daily exercise

c) about one Calorie per kilogram of body weight per hour

d) 3500 Calories per day

e) about 10% of the calories provided by the food eaten at a meal

Question #3

Specific dynamic action is the energy needed to:

a) carry out a specific set of moving exercises

b) exist for 24 hours under normal conditions with no exercise

c) digest and metabolize food

d) convert one kilogram of adipose tissue into energy

e) maintain life for one hour with neither exercise nor food

Question #4

In the Energy Equation, exercise represents:

a) all energy expenditure except that lost through basal metabolism

b) energy expended in sports

c) energy expended in activities designed to maintain good health

d) the composite of all energy expended through physical work of any kind

e) all energy expenditure beyond the level of 1 Cal per minute

Question #5

Of the following statements, the one that is true is:

a) one carbohydrate Calorie provides more energy than one protein Calorie

b) one Calorie of a fat or an oil provides more energy than one protein Calorie

c) one Calorie of a fat or an oil provides more energy than one carbohydrate Calorie

d) one carbohydrate Calorie provides move energy than one Calorie of a fat or an oil

e) each of these statements is false

Question #6

Of the following, the food that has a nutritive value of about 9 Cal/g is: a)corn oil

b)table sugar

c)protein

d)lactose

e)starch

Question #8

Fats and oils are differentiated from each other on the basis of their:

a)melting points

b)densities

c)optical activities

d)glycerol content

e)boiling points

Question #9

Triglycerides are used in the manufacture of: a)soap

b)vitamins

c)synthetic detergents

d)high-octane gasoline

e)enzymes

Question #10

Heating a red-orange mixture of a vegetable oil with tincture of iodine causes the disappearance of the colour because:

a)the iodine adds to the double bonds of the oil’s side chains

b)the vegetable oil undergoes hydrolysis to a soap and glycerol

c)the iodine converts the triester to a hydrocarbon

d)the oil becomes hydrogenated to a saturated fat

e)the iodine converts the oil to a colorless carbohydrate

Question #11

On the molecular level, fats are more likely than oils to have:

a)much unsaturation and short side-chains

b)little unsaturation and short side-chains

c)much unsaturation and long side-chains

d)little unsaturation and long side chains

e)neither unsaturation nor side-chains

Question #12

Vegetable oils and fish oils differ from animal fats primarily in that the vegetable and fish oils contain: a)carbon-carbon double bonds

b)oxygen atoms

c)glycerol units

d)nitrogen atoms

e)peptide bonds

Question #13

Cholesterol is a: a)fully saturated triglyceride

b)highly unsaturated triglyceride

c)fatty acid

d)steroidal alcohol

e)drying oil

Question #14

Cholesterol does not occur in: a)butter

b)beef fat

c)lard

d)coconut oil

e)human fat

Question #15

The animal body stores its excess energy largely as: a)carbohydrates

b)cellobiose

c)glyceryl triesters

d)proteins

e)polysaccharides

Question #16

An example of a disaccharide is: a)sucrose

b)galactose

c)dextrose

d)D-glyceraldehyde

e)fructose

Question #17

The name carbohydrate reflects:

a) the ratio of carbon to hydrogen in the molecule

b) the ratio of carbonyl groups to total carbon content

c) the combined rations of carbon, hydrogen and oxygen

d) the ratio of carbon to oxygen

e) the ratio of hydrogen to oxygen

Question #18

A substance is optically active if it:

a)produces polarized light

b)absorbs polarized light

c)rotates the plane of polarize light

d)converts polarized light into unpolarized light

e)converts unpolarized light into polarized light

Question #19

Glucose is also known as dextrose because glucose:

a)was discovered by James Dexter

b)is an aldohexose

c)rotates plane polarized light in a clockwise direction

d)is made up of molecules shaped like a right hand

e)was first observed in a microorganism of the dextronia family

Question #20

To be chiral, a carbon atom must be:

a) part of a carbohydrate molecule

b) bonded to a carbonyl group

c) bonded to four different atoms or groups

d) bonded to an –OH group

e) bonded to at least two other groups

Question #21

Invert sugar is another name for:

a)glucose

b)fructose

c)galactose

d)maltose

e)a mixture of equal amounts of glucose and fructose

Question #22

Potato starch is a nutrient while lettuce is a low-calorie roughage because:

a)humans lack cellobiase

b)starch is composed largely of glucose units while lettuce is composed largely of galactose units

c)the monosaccharide units of starch are joined to each other through glycosidic links while those of lettuce are joined through ester links

d)humans cannot digest and metabolize galactose

e)potatoes are generally cooked while lettuce is eaten raw

Question #24

The component common to all dietary roughage and fiber is: a)complete protein

b)essential amino acids

c)nonessential amino acids

d)polyunsaturated triglycerides

e)indigestible carbohydrate

Question #25

Lactase is:

a)the trade name for an artificial sweetener

b)a disaccharide made up of galactose and glucose

c)the enzyme that aids in the digestion of milk sugar

d)another name for invert sugar

e)an aldotriose

Question #26

The carbohydrate among the following that does not provide the body with 4 Calories per gram is: a)sucrose

b)starch

c)fructose

d)cellulose

e)galactose

Question #27

The number of different amino acids that combine to form human protein is generally recognized as: a)10

b)20

c)35

d)45

e)60

Question #28

Amino acids show unusual chemical behaviour especially because they:

a)contain the elements carbon, hydrogen, oxygen and nitrogen

b)contain the amide functional group

c)are chiral

d)are all found in living organisms

e)contain both an acidic and a basic functional group on the same molecule

Question #30

For most of us, our principal contact with amines in consumer products comes through:

a)fragrances used in the manufacture of soaps and synthetic detergents

b)headache remedies

c)wrapping material used for frozen foods

d)artificial food colourings

e)the odour of fresh seafood

Question #31

For humans, the number of essential amino acids is about: a)5

b)10

c)15

d)20

e)25

Question #32

High quality protein is protein that:

a) contains all the amino acids found in human protein

b) contains all known amino acids

c) contains all the essential amino acids in the same sequence as they are found in human protein

d) contains all the essential amino acids in about the same ratio as they occur in human protein

e) contains all the essential amino acids and none of the nonessential amino acids

Question #33

Eggs are a particularly rich source of: a)carbohydrates

b)high quality protein

c)triglycerides

d)micronutrients

e)polyunsaturated acids

Question #34

Eggs might be considered a perfect food except for their considerable content of: a)protein

b)triglycerides

c)sodium

d)fatty acids

e)cholesterol

Question #35

The peptide link of proteins is identical with the chemical group known as the: a)aldehydes

b)amide

c)carboxylic acid

d)ester

e)ketone

Question #36

The number of different tripeptides that can be formed from three different amino acids with each tripeptide containing each of the three amino acids is: a)2

b)4

c)6

d)8

e)10

Question #37

The primary structure of a protein refers to:

a) its location or origin in a plant or animal body

b) the sequence of the amino acids that form it

c) the number of individual amino acids that it contains

d) its function in any biological system

e) the part of the protein first biosynthesized

Question #38

The conversion of the secondary structure of a protein into another secondary structure of less importance or smaller activity is known as: a)inhibition

b)denaturation

c)hydrolysis

d)depeptidization

e)deprotonization

Question #39

Isotopes do not have the same:

a) atomic number

b) number of electron shells

c) number of neutrons in the atomic nucleus

d) number of protons in the atomic nucleus

e) number of electrons

Question #40

Percentage concentration often refers to:

a) moles of solute per litre of solvent

b) grams of solute per 100 g of solution

c) moles of solute per 100 millilitres of solution

d) grams of solute per litre of solution

e) milligrams of solute per litre of solution

Question #41

Sodium chloride acts as an electrolyte because sodium chloride:

a)is soluble in water

b)produces ions when it dissolves in water

c)is held together by covalent bonds

d)is a crystalline solid

e)is a colorless solid

Question #43

The nucleus of an atom may contain: a)protons and electrons

b)neutrons and electrons

c)protons and neutrons

d)protons, neutrons and electrons

e)only protons

Question #44

The molecular formula of an alkane that exists as two and only two isomers is: a)C2H6

b)C3H8

c)C4H10

d)C5H12

e)C6H14

Question #46

The strength of an ionic bond comes principally from:

a) the mutual attraction of opposite electrical charges

b) the conversion of atoms into compounds

c) the conversion of compounds into atoms

d) the conversion of atoms into ions

e) the movement of electrons from cations to anions

Question #47

The total number of shared electrons in a carbon-carbon double bond is: a)2

b)3

c) 4

d)5

e)6

Question #48

The easiest way to obtain a mole of any chemical is to:

a)count out the correct number of chemical particles of that substance, one by one

b)obtain exactly one gram of the substance

c)obtain the atomic number or molecular weight of the substance, measured in atomic mass units

d)obtain the atomic or molecular weight of the substance in grams

e)obtain one atom or one molecule of the substance

Question #50

In the reaction C + 2H2 CH4, one mole of carbon atoms reacts with exactly: a)one mole of hydrogen molecules

b)two moles of hydrogen molecules

c)one g of hydrogen molecules

d)two g of hydrogen molecules

e)6.02 x 1023 hydrogen molecules

Question #51

An alkane is defined by:

a)its reaction with sodium

b)its molecular formula

c)the products it produces on combustion

d)its origin in petroleum

e)its physical properties

Question #53

One mole of water (H2O) and one mole of carbon dioxide (CO2):

a)have the same weight in grams

b)contain the same number of oxygen atoms

c)contain the same weight of oxygen atoms

d)contain the same number of molecules

e)contain the same number of carbon atoms

Question #54

The function of lipoproteins in blood serum is to: a)aid in clotting

b)transport cholesterol

c)maintain pH

d)remove defective red blood cells

e)All of the above

Question #55

Liquid vegetable oils are converted into solid shortening by chemical addition of: a)bromine

b)iodine

c)water

d)hydrogen

e)sodium hydroxide

Question #56

The Mo-99 isotope is made from the Mo-98 isotope by a process of: a)radioactive decay

b)neutron activation

c)electron bombardment

d)addition of a proton

e)gamma radiation

Question #58

The coldest substance on the planet is: a)dry ice

b)liquid helium

c)supercooled water

d)liquid air

e)liquid oxygen

Question #59

Charles law relates:

a) the volume of a gas and its pressure

b) the number of moles of a gas and its volume

c) the ratios of combining gases in a reaction

d) the volume of a gas and its absolute temperature

e) all of the above

Question #60

The ease of combustion of snack foods such as potato chips is primarily due to:

a)their fat content

b)their salt content

c)their carbohydrate content

d)their protein content

e)all of the above

Question #61

A 341 mL can of Classic coke contains approximately how many grams of sugar? a)100

b)28

c)34

d)10

e)42

Question #62

Lecithin acts as a potent emulsifying agent because:

a)it is highly soluble in water

b)it has both polar and nonpolar components in its molecular structure

c)it is a fat

d)it does not readily react with fats or water

e)it is a protein

Question #63

Consider a molecule “X” with 5 non identical chiral centres. The total number of possible optical isomers for “X” is: a)8

b)16

c)32

d)128

e)256

Question #64

For a healthy balanced diet, the following % of calories from each of the macronutrients is recommended

a)33.3 % fat, 33.3% protein, 33.3% carbohydrate

b)10% fat, 30% protein, 60% carbohydrate

c)30% fat, 15% protein, 55% carbohydrate

d)20% fat, 30% protein, 50% carbohydrate

e)40% fat, 20%protein, 40% carbohydrate

Question #66

The Atkins diet advocates: a)low protein consumption

b)high carbohydrate consumption

c)low carbohydrate consumption

d)calcium supplements

e)low calorie consumption

Question #68

The most abundant organic molecule on Earth is: a)glucose

b)water

c)cellulose

d)methane

e)carbon dioxide

Question #69

Type II diabetes:

a)always requires insulin treatment

b)never requires insulin

c)can often be controlled by weight loss and reduced sugar intake

d)occurs only in mature adults

e)causes uncontrolled lipolysis of fat

Question #70

The main challenge of vegetarian diets is:

a) to get enough calories

b) to get enough carbohydrates

c) to get enough fibre

d) to get enough high quality protein

e) to get enough omega-3 and omega-6 fatty acids

True or False

1 mark each

T/F

The solute is the major part of a solution

T/F

Consumption of whisky helps keep the body warm

T/F

Only protons and electrons are found in the nucleus of an atom

T/F

Cholesterol is essential for human health

T/F

Organic aldehydes and ketones both contain a carbonyl group

T/F

In diabetics, blood sugar levels are too low

T/F

Saturated fats have a higher caloric value than unsaturated fats

T/F

All bacteria are dangerous to humans

Dihydroxyphenylalanine (DOPA) has been somewhat successful in treating Parkinson’s disease

T/F

T/F: Question #72

The atomic weight of an element represents the weighted average of the masses of all its isotopes.

T/F: Question #73

Elements in the same group of the periodic table have the same number of outer shell electrons.

T/F: Question #74

All elements listed in the periodic table are found naturally.

T/F: Question #75

All of the noble gases such as He, Ne, Ar, Kr, Xe are completely unreactive.

T/F: Question #76

Ionically bonded compounds tend to have higher melting points than do covalently bonded ones.

T/F: Question #77

Trans fats can be completely eliminated from our diet with proper precaution.

T/F: Question #79

Both D- and L- amino acids occur widely in nature.

T/F: Question #80

All molecules are compounds.

T/F

Adenosine triphosphate (ATP) is the basic “energy currency” of the human body

Structure Identification

10 marks, 1 mark each

Structure Identification

Short Answer

10 marks

Short Answer: Question #1

The half life of the Tc-99 isotope used in diagnostic medical imaging is 6 hours. If a patient is injected with 200 mg of this isotope, what quantity will remain after 18 hours? (4 marks)

After 1 half life (6 hr) : 200x.5=100mgAfter 2 half lives (12hr) 100x.5=50mgAfter 3 half lives (18) hr 50x.5=25 mg

Short Answer: Question #2

A new brand of luncheon meat is advertised as being 82% fat free. One hundred grams of this meat provides 300 Calories of nutritional value. (6 marks total) i)What weight of fat is in 100 grams? (1mark) 18 grams

ii)How many Calories from this fat? (2 marks) 18 x9= 162

iii)Assuming that protein is the only other macronutrient present, how much protein is present in 100 grams of this meat? (2 marks): 138 Calories left. Since protein supplies 4 Cal/gr, amount of protein =138/4= 34.5 gr

iv)What material accounts for the remaining weight of the meat? (1 mark) Water

End of review questions for midterm exam Summer 2009

Identifying structures by components Phenol Bisphenol A Phenyl alanine

More phenolics

Acetaminophen Ibuprophen (ibuprofen)

Even more phenyls………..

PBDE (polybromodiphenyl ether)

Compounds with the acetyl group Acetylcholine Acetylsalicylic acid (ASA or aspirin) acetaminophen

Beta phenyethylamines (CNS active) Some examples Methamphetamine and its precursor

The steroid skeleton (6,6,6,5 ring) Estrone (a ketone) Estradiol (2 OH’s)

More steroids

Cholesterol (an alcohol) Testosterone (a ketone in Ring A)

The opiate skeleton

Oxycodone (a ketone) Morphine Heroin?

Glycerol and glycerides

Glycerol

Glycerol monostearate

Define the following terms

OTC : over the counter NSAID’s: non steroidal antiinflammatory

drug CNS:Central nervous system GRAS:Generally regarded as safe BMI:Body Mass Index LD50. Lethal dose to 50% of a population

Connect the short form with its connotation/ application DDT effective vs. malaria AZT an anti-AIDs drug PCB used in transformer oil HGH promotes growth PNAH 1st known

carcinogens

Match the following (1 extra!) Amphetamine stimulant Prozac antidepressant Erythromycin antibiotic Valium tranquilizer

ibuprofen Estrone sex hormone

Associate each with claimed benefit Ginko biloba improves blood

flow Echinacea immune system Aloe skin conditioner Cranberry urinary tract St John’s Wort antidepressant

Connect Nobel winners with discovery Paul Erlich the first antibiotic Marie Curie Discovery of radioactivity Willard Libby 14C dating Elie Metchnikoff probiotic bacteria Alexander Fleming penicillin

Watson and Crick DNA double helix Barry Sharpless Synthesis of chiral molecules

Fritz Haber chemical synthesis of ammonia

The LD50 of caffeine in mice is 0.13g/kg Assuming the same toxicity in humans,

how many cups of Starbucks Special Cappucino (195 mg caffeine/cup) would be needed for a 50% fatality risk in a 70 kg human?

For a 70 kg person, need 70 x.13 gr= 9.1 grams

Thus, # of cups needed= 9.1/.195 ~45 cups

The acidity of colas is caused by phosphoric acid If the pH of cola is 3.0, how many moles

of phosphoric acid are in a 2.0L bottle?

Tough question!

If pH is 3, then [H=] =10-3 or .001mole/L Thus, in 2 L bottle, would have 2 x .001

or .002 moles of H+. Could also write it as 2 x 10-3.

Recall, pH= -log10 [H+]