Watch the Video “Food: Delicious Science, We Are What We Eat” and answer the following questions. Reference your textbook, the PPt Lectures, your notes, or other resources when necessary.
Food and Our Bodies
Rice and energy
What food type provides a quick source of energy?
What is the simple sugar that fuels our bodies? What is its chemical formula?
Is grinding rice a physical or chemical process?
When an ounce of rice is burned 35 Cal (kcal) of energy is produced. What type of chemical reaction occurs when rice is burned? What is 35 Cal of energy in J?
What process occurs during cooking that makes the carbohydrates in rice more digestible? Is this a physical or chemical process?
How much energy is required to release the starch from 1 cup of rice grains? How much energy to we receive when we eat 1 cup of cooked rice? Convert each amount to J/g
If there are 4 kcal/g of energy produced by eating carbohydrates, how much rice in ounces would have to be consumed to provide 250 kcal of energy?
Chemical Reactions and Wheat
Yeast feed on glucose to produce carbon dioxide and water. What type of chemical reaction is this? Write the balanced chemical reaction.
While kneading dough a chemical reaction occurs between two smaller proteins (peptides) in wheat to produce the protein gluten. What type of chemical bonds are formed between peptides to form proteins? Are these bonds ionic or covalent?
The sugars in wheat are broken down into lactic acid is produced by one set of microbes and another set of microbes break down to lactic acid into carbon dioxide and water. What are these two different microbes and during what stage of making sour dough bread are they active?
The lactic acid in sour dough bread and gives the bread its distinct tangy flavor. What is its chemical formula?
What species must be produced in solution for lactic acid to be classified as an acid?
Give the balanced chemical equation for the combustion of lactic acid.
Eggs and Proteins
What are some examples of proteins produced by the body? What are the building blocks that we use to produce our own proteins?
Is slicing open an egg shell a physical or chemical change?
Egg white contains 11% protein in water. What concentration unit(s) (m/m%, m/v%, v/v%, M) may be expressed by this amount? Explain your answer.
Is cooking an egg a physical or chemical process? Why are the proteins in cooked eggs more readily digestible than those in raw eggs?
An an egg contains 6.0 g of protein, and only 50% of that amount is digestible when an egg is eaten raw. If a body builder drinks two raw eggs each morning, how much energy is available for use by the body if every gram of protein provides 4.0 kcal of energy?
Fats and oils
What are the building blocks of fats called? What characteristics cause different fats to be solids or liquids at room temperature?
What makes acetone a good solvent for extracting fats from substances such as milk?
Vitamins and Minerals
- What are three minerals needed by the human body? What food sources can we get them from and what purpose do they serve in the body
- Are these minerals found as pure elements or as ions in food sources?
- What process was used to extract the calcium in the form of calcium phosphate from milk? What type of reaction occurred? Give a possible balanced chemical equation for the reaction.
- How does the presence of acid in our stomachs when we drink milk affect our ability to absorb calcium ions in milk?
- What vitamin is required to absorb calcium from our diet?
- Mushrooms are able to produce vitamin D from ergosterol. Is an input of energy required for this process? If so, what is the source of this energy?
- What type of process requires an input of energy?
