Question

What’s for Lunch? A Case Study in Macromolecules

Part I

You and your friend Maria are supposed to meet at your place for lunch to catch up with each other. You’ve both been craving burritos, so she picks up a couple and brings them by. As you sit down and start eating, Maria looks at your burrito bursting with ingredients, and looks at her own burrito, which is plainer and contains only rice, sour cream, and cheese. She wonders out loud, “It seems weird that we can both get all the energy and nutrients we need from such different foods. Or can we? I’ve been feeling tired lately, but I’m eating and stuff. Maybe I just need to drink more caffeine. Those Monster drinks help for awhile.”

As you quietly munch your flavorful food, your mind turns back to your biology course. You wonder if what Maria is eating does provide her with all the nutrients she needs. You say, “Hey, I have an idea. Let’s look at what you’re eating and see if you’re getting all the major groups of macromolecules. I’m no dietitian, but maybe we can figure something out based on what I’ve learned in bio.”

1. Analyze Maria’s burrito by filling in the chart below.
   

Burrito Ingredient	Macromolecule	Monomer	Biological Functions
Flour tortilla	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
Rice	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
Sour cream	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
Cheese	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER

2. What class or classes of macromolecules is missing in Maria’s burrito? Please list them as well as each class’s monomer and biological functions.

INSERT ANSWER

3. Use the template below to make your own chart for what you would eat in a burrito.
   

Burrito Ingredient	Macromolecule	Monomer	Biological Functions
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER
INSERT ANSWER	INSERT ANSWER	INSERT ANSWER	INSERT ANSWER

4. Are you missing any classes of macromolecules? If so, please list them below.
   INSERT ANSWER

Part II

After working through the macromolecules in your friend’s extremely pale burrito, you look at her and think you might have an idea about what is going on. You ask Maria, “Do you usually eat like this?” “Yup,” she says, “I love all the carbs, rice, and bread, as well as cheese. Sometimes I eat a piece of fruit or some carrot sticks. And energy drinks!” You then point out to your friend that she seems to be getting very little protein, a major class of macromolecules. But she is getting plenty of carbohydrates and lipids in the form of animal fats.

1. While your body can convert the monomers of macromolecules from one to the other, it has to have the raw materials in the form of the appropriate atoms. You explain to your friend that when she eats proteins, they are broken down into amino acids through the process of INSERT ANSWER and can then be rebuilt into new proteins through the process of INSERT ANSWER.

1. If your body does not take in protein, but only carbohydrates and lipids, what atoms will it be missing? Hint: There are two, and you can figure this out by comparing the structures of the monomers for proteins and carbohydrates as well as the basic structure of lipids.
   INSERT ANSWER

2. For the above atoms, how many electrons are in the outer shell?
   INSERT ANSWER

3. For the above atoms, what type of bond will they make within the amino acid monomer?
   INSERT ANSWER

4. Even if your friend does obtain the correct atoms, there are still a couple amino acids that your body cannot manufacture from scratch, but must be ingeste What are these amino acids?
   INSERT ANSWER

2. Why might a lack of protein or the wrong types of proteins lead to your friend’s fatigue?
   INSERT ANSWER

Part III

“Well,” Maria states as she finishes her burrito, “I might have to adjust my diet a little, but I still think that caffeine will help me get the energy I need short term. And I might have become reliant on Diet Coke with all these late nights at work.”

You think about this. You don’t remember caffeine as a macromolecule you learned about. But you do remember talking about a class of macromolecules that can be used by the body for energy.

1. What is the class of macromolecule that can be used directly in cellular respiration to make ATP (energy currency of the cell)? What is the specific molecule that feeds into cellular respiration?
   INSERT ANSWER

2. Is caffeine really a source of energy? Write a paragraph explanation for your friend. She will only accept information from a reliable source, so make sure your source(s) of information is reliable and cite it here. Be sure to use APA Style to cite any sources!
   INSERT ANSWER

Answer 1

PART : 1 MARIA BURRITO ANALYSIS

INGREDIENTS	MACRO MOLECULES	MONOMER	BIOLOGICAL FUNCTION
FLOUR TORTILLA	STARCH	GLUCOSE	ENERGY PRODUCTION
RICE	STARCH	GLUCOSE	ENERGY PRODUCTION
SOUR CREAM	FAT	FATTY ACID &GLYCEROL	ENERGY PRODUCTION AND STORAGE
CHEESE	PROTEIN	AMINO ACIDS	GROWTH AND REPAIR OF BODY TISSUES

ANSWER : 2

MARIA has almost all carbohydrate in her Burrito but protein quantity is very less as compared to her friend. Most of the ingredients provide starch and fats to her.

ANSWER : 3 (CHART)

• in comparison to her my own burrito will have following nutrient composition :

INGREDIENTS	MACRO MOLECULE	MONOMER	BIOLOGICAL FUNCTION
WHEAT FLOUR TORTILLA	STARCH	GLUCOSE	ENERGY PRODUCTION
BOILED FRY POTATO MASHED	STARCH	GLUCOSE	ENERGY PRODUCTION
MILK CREAM	FAT	FATTY ACIDS AND GLYCEROL	ENERGY PRODUCTION AND STORAGE
PANEER CUBES/EGG	PROTEIN	AMINO ACIDS	GROWTH OF MUSCLES, BONES
MIXED VEGGIES LIKE BEANS, CARROTS, PEAS PIECES	MINERAL AND VITAMINS	Fe, Cu, Mn , vitamins A, B, etc	MAINTENANCE OF BODY HEALTH

ANSWER: 4

As compared to Maria my Burrito will have more protein as I have added eggs, beans, paneer pieces.Carbohydrates and fats are already sufficient .Vitamins and Minerals from vegetables are enriching nutrient value of my food.Maria seem to binge on more carbohydrates and fats instead of proteins . So she is not going to get sufficient proteins for her muscles and other body tissues. That is why she get fatigue easily.

PART II (FILL IN THE BLANKS)

1. digestion; protein synthesis/translation

(a). Nitrogen ; Sulphur are two atoms which will be missed if we do not take proteins. We can not find them in carbohydrates and fats.

b). For nitrogen (Z=7) no of electrons in outermost shell will be 5 and 6 electrons in Sulphur's outermost shell because Sulphur has atomic no. Z=16.

c) Inside amino acid monomer N will make covalent bond with alpha carbon atom and other hydrogen atoms. Sulphur also attached with carbon atom in cysteine via covalent bond

d) These amino acids are called essential amino acids which can be taken in diet and provide us N and S atoms for example Lysine and Histidine provides N atom and Methionine provides S atom .

ANSWER (2) Lack of protein is harmful to our body as all of our muscles are made of proteins like actin and myosin . If we don not take sufficient protein in our diet then muscle will weaken and become cause of all sorts of problem like fatigue and dystrophy. Protein also help in building oxygen transporter Hemoglobin and Iron carrier in our body other than collagen .

PART : III (answers)

1. Carbohydrates are macro molecules which provide us direct supply of energy . Here glucose is the instant source of energy. It directly enters the cell and participate in respiration process to produce ATP molecules.

2. Caffeine is a type of stimulant alkaloid found in tea and coffee. It is normally not a source of energy and can be used in treatment of various diseases or disorders. If Maria has got addicted to caffeine she can not resist taking it again and again while taking her general meal. Coffee affect Central nervous system and muscles. It raise the blood pressure and pulse rate. It causes mild anxiety and insomnia if taken regularly for long. It also causes dehydration of body.

3. SOURCE OF INFORMATION :

Caffeine and CNS : mechanism of action biochemical , metabolic and psychostimulant effects , Nehlig A, et al- Brain Res Rev. 1992-May-Aug ;17(2): 139-70