martes, 29 de junio de 2021

2021 ch 4. Biocompuestos (Biocompounds).

 Período 1. Capítulo 3. Semana 7.

Ø    Preliminares

Tiempos Desde (08-04-2021) hasta (14-04-2021). Nota de puntualidad 50. Desde (15-04-2021) hasta (19-04-2021). Nota de puntualidad 40.

Desde (20-04-2021) hasta (21-04-2021). Nota de puntualidad 30. Después del (21-03-2021) Nota de puntualidad 20, más penalización de 5 puntos en cada actividad.

Eje temático - Bioelementos, biocompuestos y nutrición

Objetivos - Reconocer las moléculas que constituyen a las células, tejidos, órganos, sistemas y organismos y lo indispensables  que son ellas para el sostenimiento de la vida sobre la tierra

Ø    Contents and activities

        Engagement

 (4.1) Look to the images below and write five 5 words associated with these images.

        Exploration

 (4.2) Ask your parents: Which kind of food makes up a healthy diet? Why? (give your anwser in Spanish)

(4.3) Why Junk food is a bad idea to keep us healthy? (give your anwser in Spanish)

Explanation

(4.4) Read the following text

Biocompounds

1.      Significance of Carbon

A compound found mainly in living things is known as an organic compound. Organic compounds make up the cells and other structures of organisms and carry out life processes. Carbon is the main element in organic compounds, so carbon is essential to life on Earth. Without carbon, life as we know it could not exist.

2.      Compounds

A compound is a substance that consists of two or more elements. A compound has a unique composition that is always the same. The smallest particle of a compound is called a molecule. Consider water as an example. A molecule of water always contains one atom of oxygen and two atoms of hydrogen. The composition of water is expressed by the chemical formula H2O. A model of a water molecule is shown in Figure below. Water is not an organic compound.

A water molecule always has this composition, one atom of oxygen and two atoms of hydrogen.

What causes the atoms of a water molecule to stick together? The answer is chemical bonds. A chemical bond is a force that holds molecules together. Chemical bonds form when substances react with one another. A chemical reaction is a process that changes some chemical substances into others. A chemical reaction is needed to form a compound. Another chemical reaction is needed to separate the substances in a compound.

3.      Carbon

Why is carbon so basic to life? The reason is carbons ability to form stable bonds with many elements, including itself. This property allows carbon to form a huge variety of very large and complex molecules. In fact, there are nearly 10 million carbon-based compounds in living things! However, the millions of organic compounds can be grouped into just four major types: carbohydrates, lipids, proteins, and nucleic acids. You can compare the four types in Table 4-1.

(4.5) Read the following text or see the YouTube Tutorial

Flavors of biocompounds

YouTube Version:  https://www.youtube.com/watch?v=sBXn6xih4JU

Biocompounds are not just things that appear in textbooks, you actually find them every day in your tongue.

Aminocids and complex flavors

Amino acids, in addition to their vital role in muscle building, brain activities, dietary supplements, significantly contributes to enhance the flavor of your food. Amino acids Glutamate and Aspartate, are the flavor enhancers that are at work to make your food more delicious and serve your taste buds.

Why do Ripe Tomatoes Taste Better?

Tomatoes ripen and turn red when they receive plenty of sunlight. Their amino acid content also increases as they ripen, turning them sweeter. The amino acids glutamate and aspartate are responsible for the taste of tomatoes, and their ratio is crucial. When glutamate and aspartate are present in a 4:1 ratio, tomatoes have the most tomato-like taste. In short, riper tomatoes are sweeter and have a higher amino acid content so they taste more delicious.

fig 4.1. Without glutamate, tomatoes would taste more like weak apple juice or a sour apricot.

Amino Acids are Responsible for the Unique Taste of Crab and Sea Urchin

Arginine is a bitter amino acid that brings out the unique taste of seafood. Here is a surprising fact. The taste of crab comes from just a few amino acids working together with nucleic acids and minerals, as shown above. The distinctive taste of sea urchin comes from a set of amino acids that includes bitter-tasting methionine and valine. Sea urchin taste can be reproduced in the lab by combining the five amino acids above in the same ratio found in actual sea urchins. When methionine is omitted, the taste becomes much like shrimp or crab.

fig 4.2. Crab and Sea Urchin Taste.

Fresher is Better isn’t Always True

Breakdown of proteins increases the amino acid content for more delicious taste. When lions catch their prey in the wild, they first eat the pancreas, small intestines, and liver. These organs are richer in amino acids than muscle and so they taste better. Two or three days later after the lions have left their prey, hyenas and other animals move in to eat the muscle. By that time, the muscle proteins have started to break down into amino acids and nucleic acids, making the meat taste much better. Similarly, sashimi (raw fish) also tastes better after a certain amount of time has passed rather than immediately after the fish is caught. The amino acids and nucleotides in the flesh become abundant about 12 to 24 hours after capture.

Where does the Complex and Delicious Taste of Fermented Foods Come From?

Since ancient times, mankind has found ways to grow, harvest, and preserve foods. Now, instead of simply preserving food, we have developed food cultures that involve the preparation and processing of foods to make them taste more delicious.

Fermentation is one of the techniques that we have learned to make food more delicious. Proteins by themselves do not have much taste. However, if we ferment foods such as soy, fish, and milk, the proteins are digested and become amino acids, which produce various tastes. Because fermented foods are packed with amino acids, they are rich in flavor — and they are also easily preserved.

Amino acids are used as flavor enhancers and seasonings to make foods everywhere taste more delicious and unique. Amino Acids Work Together for Different Tastes! Each amino acid has a unique taste. How a food tastes depends largely on what amino acids it contains? When we study the content of foods, it becomes clear that the types and amount of amino acids have a strong effect on the taste.

fig 4.3. Amino Acids Work Together to Produce the Taste of Foods!

Fats: flavor enhancer, cooking medium, distinct flavor

Flavors are carried, formed altered, and enhanced in fat--from butter to olive oil, duck fat to lard.  In their pure form, quality fats stand alone in greatness.  Their richness and mouth feel or their bitterness and bite are distinct qualities which draw us to find and use the best.  Fats also carry flavor, enrich sauces and provide a gentle medium in which to cook.

    We respect fats.  While their pleasures are grand, great displeasure comes from the misuse of fat.  For instance, the addition of too much butter to a sauce detracts from both the flavors developed in the sauce and the enriching quality of the butter—the sauce becomes cloying.  If we overheat oil in a sauté pan an acrid taste forms ruining what is to be or already is cooking.  When making vinaigrettes the addition of too much or not enough olive oil detracts or overwhelms the delicate balance of the vinegar and seasonings.

    Our relationship with fat is based on a balance in our cooking.  Understanding fats and what they are to be used for is important.  Duck fat has an intense richness which imparts its character on what is being cooked, from sautéed vegetables to poached fish.  In the case of the poached fish, the fish is surrounded in a uniformly warm environment which keeps the fat and moisture in the fish.  Olive oil posses similar characteristics to that of duck fat from flavor delivery to uniform cooking medium.  Unfortunately in the case of olive oil heat eventually destroys its nuances.  Thus for using as a cooking medium the heat must be kept even lower.  Furthermore in comparing duck fat to olive oil we find olive oil to be a leaner fat and thus a better partner with richer products.  We are looking for a balance between cooking medium and product being cooked to highlight the final dish.

Butter is rich and decadent in its emulsified state, but when it is heated it separates and develops a greasy taste.  In order to use butter in a warm state we must emulsify it with water, stock or another liquid.  In keeping the butter in its emulsified state we are able impart butters richness and flavor to meats, fish, fruits and vegetables in the form of a cooking medium or as a light finishing glaze.  The butter will then carry the flavor of whatever it coats to the palate quickly and decadently.  Butter can also impart a rich toasty flavor to ingredients if its solids are allowed to caramelize.  When roasting ingredients we add butter to the pan and allow it to foam and slightly caramelize.  We then baste our ingredients with this butter.

    Fats carry the flavor onto what is being cooked.  In the case of butter either emulsified or browned, it can carry the flavor of herbs and spices added to the pan during the cooking process.  The flavors bloom in the fat and the ingredients benefit from this infusion. 

Sweetness, flavor enhancement, and flavor balance

The most notable function of sugar in food is its sweet taste. Sweet taste serves as a sensory cue for energy as well as a source of pleasure. Sweetness is one of a few tastes which are innate, and it has been argued that a preference for sweet taste evolved to ensure that animals and humans chose foods that are high in calories and nontoxic (Spillane 2006). During infancy, the heightened preference for sweet tastes may have ensured the acceptance of nature's first food—mothers’ milk. Human breastmilk naturally contains 2.12 g of sugar per 1 fluid ounce. Therefore, these taste mechanisms apparently had a significant effect on survival.

Sweetness improves the palatability of food. Thus, adding sugar to foods with high nutrient quality may increase the chance that they are consumed. Chocolate milk is an example of increasing the palatability of milk for kids, which provides important nutrients particularly calcium, potassium, and vitamin D. Sweetness from sugar can also improve the palatability of foods for the elderly by compensating for the chemosensory losses that the elderly experience.

Elaboration

(4.6) Case Study: A Can of Bull? Do Energy Drinks Really Provide a Source of Energy?”

·       Research ingredients found in 4 popular energy drinks and state if they are: proteins (aminoacids), sugars, lipids, or nucleic acids (nucleotides). (Answer in Spanish)

(4.7) Make a conceptual map with the information presented in flavors of biocompounds (use the text or the video https://www.youtube.com/watch?v=sBXn6xih4JU). (answer in Spanish)

(4.7) What is the importance of breaking down proteins into amino acids for the flavor profile of a meal? Explain your answer (answer in Spanish)

(4.8) Explain why human infants and children have a preference for sweet foods using the information from the video. (answer in Spanish)

Evaluation

(4.9) Answer the following questions (if possible do it in this link: https://forms.gle/FVQ7THfDzxbPUS388). Mark with an “X” over the letter.

1.    What is the main function of carbohydrates?

a.     provides energy to cells, stores energy, forms body structures

b.    helps cells keep their shape, makes up muscles, speeds up chemical reactions, carries messages and materials

c.     stores energy, forms cell membranes, carries messages

d.    contains instructions for proteins, passes instructions from parents to offspring, helps make proteins

2.    Which are the chemical elements that forms most of the biomolecules?

a.      Carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and phosphorus (P)

b.     Chlorine (Cl), Tungsten (W), lead (Pb), gold (Au), and nitrogen (N)

c.      Magnesium (Mg), Oxygen (O), hydrogen (H), carbon (C), and nitrogen (N)

d.     Phosphorus (P), nitrogen (N), oxygen (O), and hydrogen (H)

3.    Which of the 4 biomolecules types passes information from parents to offsprings?

a.     Proteins

b.    Lipids

c.     Nucleic acids

d.    Carbohydrates

4.     Which of the following biomolecules are examples of proteins?

a.     enzimes and fats

b.    antibodies and sugars

c.     starch, enzimes, oils

d.    antibodies, enzimes

Impacto vital

(4.10) Realizar la ilustración de la siguiente ave (Colibri coruscans) puede apoyarse en el enlace para aprender a dibujarla. Los estudiantes que trabajan de manera virtual suben el dibujo a través del siguiente enlace: https://www.youtube.com/watch?v=0CseZKgXbxc

Opcional

Por nota extra puede hacer un mapa conceptual con las características del ave dadas en el enlace anterior.

Ø    Fin de la guía 4

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