topic 4

Question 1

what are the 3 macronutrients? what are their calories? how many calories does fiber have?

Answer 1

fats (9cal/g), carbohydrates (4cal/g), and proteins (4cal/g), fiber (2 ca/g)

Question 2

What elements are the macronutrients made up of?

Answer 2

Fats and carbohydrates: C, H, O
Proteins: C, H, O, N

Question 3

What are carbohydrates? What is their general formula?

Answer 3

• they are composed of carbon (carbo) and water (hydrate) and thus has a general formula of Cm(H2O)n.
• they give us energy during their consumption (in addition to creating water and CO2)
• carbohydrates + O2 = energy + H2O + CO2

Question 4

what is glucose oxidation? What happens when the opposite occurs?

Answer 4

glucose oxidation = when carbs are consumed (carbs +o2)

opposite is when glucose produced during consumption is converted back into water and carbon dioxide

Question 5

Describe sucrose

Answer 5

• disaccharide made up of glucose and fructose
• otherwise known as table sugar
• Broken down by invertase
• Makes up most of brown sugar (sucrose + molasses)

Question 6

What is the bad news for sucrose?

Answer 6

• It causes glycation: unnatural binding of molecules (Maillard reaction) where there is engagement of protein units that have an NH2 group at one end with carbohydrate units, such that when you heat it, water is quickly given off and leads to browning.
• Advanced Glycation End (AGE) products: 2 protein chains connected to what was a sugar unit, this can cause cataracts (causes clouded lenses and you see blurry, due to protein folding in eye lens which creates clumps) and makes skin not as supple.

Question 7

Describe glucose

Answer 7

• C6 monosaccharide
• it is sometimes called dextrose
• It makes up cellulose and starch

Question 8

What characteristic of the carbohydrate structure defines the type of carb that will be built?

Answer 8

Whether the H atoms are up or down is what defines what type of carbohydrate is produced and what kind of features it has

Question 9

What is the difference between cellulose and starch?

Answer 9

the OH bonds between the glucose molecules, in cellulose the bond is diagonal (OH bond up up) making it indigestible for humans and in starch the OH bond is down and up (digestible)

Question 10

What makes a food digestible?

Answer 10

whether the enzymes matches up with the reactant (food) molecule in shape. If it is, the enzyme fits in with the reactant food and is able to make products.

Otherwise, there is a mismatch and the food is not digestible

Question 11

Describe fructose

Answer 11

• monosaccharide,
• usually an individual sweetener because very sweet.
• Honey is very sweet due to its high (39%) fructose content.

Question 12

Describe maltose

Answer 12

• disaccharide,
• sweetening agent derived from partial hydrolysis of starch,
• maltose = glucose + glucose,
• broken down by maltase which breaks it down into glucose and subsequently converts it into energy through complete oxidation.

Question 13

Break it down, what is the good news about fructose?

Answer 13

• low glycemic index, so it doesn’t cause blood sugar to rise as much as sucrose, so good substitute.

Question 14

Break it down, what is the bad news about fructose?

Answer 14

• too much at once isn’t good and modern diet is ~ 10% fructose
• When it enters bloodstream, insulin regulates it but fructose is processed in the liver and if there’s too much it makes fat and too much fat in blood is a risk for heart disease
• Fructose circumvents appetite signaling, so body doesn’t know when it is satiated.
• Some evidence suggests that excess fructose causes insulin resistance which can lead to type II diabetes.
• High fructose drinks have been associated with the risk of gout as excess fructose causes uric acid increase which creates inflamed joints (gout). This does not apply to diet soft drinks. Study says contribution to development of gout is modest.

Question 15

Describe lactose

Answer 15

• disaccharide,
• lactose = galactose + glucose, has diagonal bond so not digestible (like cellulose), which is why a lot of people are lactose intolerant
• broken down by lactase (aka Lactaid).
• lactose intolerant people tend to have high H concentrations in breath when they consume lactose.
• Northern hemisphere populations tend to have less intolerance frequency.

Question 16

order these by sweetness: sucrose, honey, glucose, fructose

Answer 16

fructose > honey (39% fructose) > sucrose > glucose

Question 17

True or false: diet soda is full of fructose

Answer 17

False, diet soda has 0g of fructose.

Question 18

What is Beano?

Answer 18

enzyme that prevents gas from beans, called alpha-galactosidase which breaks down the sugar from beans that creates gas.

Question 19

What is amylose and what breaks it down?

Answer 19

a starch which is broken down by amylase, an enzyme produced by the pancreatic and salivary glands, so chewing food helps breaking down carbs. It can also break down amylopectin, a starch like molecule that is easier to digest.

Question 20

How is High Fructose Corn Syrup (HFCS) made?

Answer 20

1. Start off with corn starch: glucose polymer
2. This polymer is broken down into single units by 3 enzymes
   * alpha-amylase,
   * glucoamylase,
   * glucose-isomerase
3. glucose isomerase which converts glucose into high % fructose (up to 90%, super sweet)
4. Final result, made into pure glucose aka corn syrup with high fructose content.

Question 21

True or false: obesity has been linked with HFCS

Answer 21

True, obesity increased with increase of HFCS.

Question 22

How much of sugar cane is sucrose? Who is the biggest producer?

Answer 22

15%, Brazil

Question 23

Why is sugar bad for your teeth?

Answer 23

when sugar and S. Mutans, a bacteria in the mouth, come together, they produce lactic acid which eats away teeth and creates cavities. Though gene removal could reduce this effect.

Question 24

True or false: candy is 50% fructose

Answer 24

False, candy is 98% sucrose

Question 25

What is invertase?

Answer 25

An enzyme that makes sugar (sucrose) into 50/50 glucose and fructose

Question 26

What does fat do?

Answer 26

- stores energy, - insulates, - buoyancy, - padding, - hormone production

Question 27

What is the difference between a saturated fat and an unsaturated fat?

Answer 27

Saturated fat = fat where all possible H atoms that can be there are there Unsaturated fat = fewer H atoms, has double bonds (decreases H atoms by 2), often liquid

Question 28

What is a polyunsaturated fat?

Answer 28

saturated fat with more than 1 double bond

Question 29

Where can you get saturated fat and what can excess do to you?

Answer 29

Can be found in meats Too much can cause build up in arteries

Question 30

True or false: Margarine often has water

Answer 30

True

Question 31

What is the difference between an unsaturated fatty acid chain and trans fats?

Answer 31

unsaturated fatty acid chain: c=c has 2 oxygens on top and 2 H on bottom trans fats: c=c has 1 hydrogen on top and 1 hydrogen on bottom in a diagonal matter

Question 32

How is margarine made?

Answer 32

To make margarine, it is usually necessary to hydrogenate (add H2) many of the double bonds in unsaturated fats to single bonds (so it is less liquid and more spreadable). This causes partial reorganization of the bonding to give rise to some trans double bonds (hydrogens in diagonal). Process: catalyst surface associates with fat’s double bond (C=C) where H2 is embedded and H2 is transferred to C=C one at a time making CIS, BUT possible rotation can occur thus forming a trans double bond so we make trans fat (less healthy).

Question 33

T or F: Natural trans fats increase cholesterol levels

Answer 33

False, no evidence has shown this

Question 34

Why is filet mignon more tender than other meats?

Answer 34

Because it has less fat

Question 35

Where does cholesterol exists?

Answer 35

In food, as cholesterol, or more commonly in our bodies where it is made

Question 36

So do cholesterol causing foods really exists?

Answer 36

Not really, some foods do already have pre-existing cholesterol, but 80% of it is made by our bodies

Question 37

What is methionine

Answer 37

Raising chickens requires more methionine, an amino acid in food used as feed supplement. Molecule methyl mercaptan is part of this process, v foul smelling, it is a gas

Question 38

What are some fat substitutes?

Answer 38

- carbohydrate based: gums, seaweed, cellulose derivatives - protein-based: microparticulates (eggs, milk) - fat-based: modified fats, more saturated fat chains are added to harden the vegetable oil so it it’s not necessary to hydrogenate

Question 39

Synthetic fats have x cals

Answer 39

0 cal/g

Question 40

Describe sucrose fats

Answer 40

short chain fats, not digested and not really a fat, more for texture, non caloric, suitable for frying, absorbs vitamins A,D,E,K (fat-soluble vitamins), causes loose stools.

Question 41

What does protein do in our bodies?

Answer 41

- important for growth, - necessary for tissue maintenance, - needed for enzymatic processes

Question 42

Protein deficiency leads to....

Answer 42

Kwashiorkor (is reversible)

Question 43

What happens when an egg turns white? This process is...

Answer 43

this is the protein denaturing – water is driven off, so protein becomes visible. Protein denaturing is irreversible

Question 44

The building blocks of proteins are...and they are defined by...

Answer 44

amino acids, the R-groups

Question 45

What are peptide/amide bonds?

Answer 45

the bond that holds the oxygen double bond to nitrogen

Question 46

What does protein folding mean for a protein?

Answer 46

Different degrees of folding define a proteins capacities and function in the body

Question 47

What is tryptophan, what does it do, and why was it banned by the FDA in 1991?

Answer 47

An amino acids used because precursor to serotonin, a neurotransmitter, which induces sleep. Though in 1991, the FDA banned it due to an impurity which contaminated the samples. They were linked to eosinophilia myalgia syndrome and people died. However, this restriction was loosened in 2001 after they realized it was because of the impurity and not the tryptophan

Question 47

Why are amino acids called that way?

Answer 47

Because they contain nitrogen (amino from ammonia H-N-H) and an acid (CO2H)

Question 47

How are proteins built? What defines the type of protein that is built?

Answer 47

water splits out from the a.a. and the CO and NH groups connect to form chain. This is an energy favourable reaction. These chains can be very long, and order of the amino acids defines the type of protein.

Question 47

What is the opposite of protein building? How does it happen?

Answer 47

Hydrolysis reaction: proteins (peptides) are broken apart by the addition of water. This is why we end up being thirsty after we eat.

Question 48

what are the essential amino acids?

Answer 48

-Methionine - Arginine (necessary for young people), - Tryptophan, - Threonine, - Valine, - isoleucine, -leucine, - proline, - histidine, - lysine.

Question 49

What is so important about the essential a.a.?

Answer 49

These need to be in the right proportions to make the appropriate body proteins. Foods don’t always have them in the right proportions. They can't be synthesized by the body

Question 50

Name the complete and incomplete proteins

Answer 50

Complete proteins: eggs, meat, fish, milk, soy, they have a balance of the necessary a.a. Incomplete proteins: wheat, corn, rice, efficient in some a.a. but deficient in others, not right proportions

Question 51

Vegetarian foods are rich in....

Answer 51

in lysine (usually deficient in what, rice, corn)

Question 52

Vegans often lack this amino acid

Answer 52

Vegans do not consume any animal products or animal derived products so they are sometimes deficient in arginine.

Question 53

Brown rice is low in...

Answer 53

lysine

Question 54

black, white, kidney, adzuki, pinto beans are high in...so we add it to...

Answer 54

lysine, so bread sometimes had added bean protein concentrate to compensate for low lysine in wheat.

Question 55

Red meat (processed and total red meat) has been positively associated with...

Answer 55

all-cause mortality in a linear fashion

Question 56

what is the recommended red meat serving size?

Answer 56

3 oz.

Question 57

What would be a good alternative to red meat?

Answer 57

Insects

Question 58

How many barrels of oil's worth does it cost to raise 1 cow?

Answer 58

5-6 barrels