1. A corn plant over the course of a summer can weigh 500 grams (dry biomass, after removing the water), yet it starts from a seed that weighs less than 1 gram. What is the primary source of this increased mass? What process(es) are responsible for the gain in mass? Explain.
2. Your friend tells you that drinking diet Red Bull provides energy. Explain to her why this is not possible.
1. The primary source of increased mass in a corn plant over the course of a summer comes from the process of photosynthesis. Photosynthesis is a vital metabolic process that occurs in the leaves of the plant. During this process, plants take in sunlight, water, and carbon dioxide from the air and convert them into glucose (sugar) and oxygen. Glucose is then used as a building block to create more complex molecules such as cellulose, starch, and other carbohydrates, ultimately resulting in increased biomass.
The process of photosynthesis can be summarized as follows:
1. Sunlight energy is absorbed by a pigment called chlorophyll in the plant's leaves.
2. This energy is used to convert carbon dioxide (CO2) from the air and water (H2O) from the soil into glucose (C6H12O6).
3. Glucose is then converted into other organic compounds, such as cellulose and starch, which contribute to plant growth and increased mass.
In addition to photosynthesis, other processes such as nutrient uptake from the soil, water absorption, and cell division also contribute to the gain in mass. Nutrients like nitrogen, phosphorus, and potassium along with trace elements are essential for plant growth and are obtained through the roots from the soil.
2. Drinking diet Red Bull does not provide energy because energy in the scientific sense refers to the capacity to do work, and the energy transferred or received by the body comes from the macronutrients (carbohydrates, fats, and proteins) we consume, not from energy drinks.
Energy drinks like Red Bull contain stimulants such as caffeine and taurine, which can temporarily increase alertness and perceived energy. However, these drinks primarily function as central nervous system stimulants, affecting neurotransmitters and stimulating brain activity rather than providing actual energy.
The energy we use in our bodies comes from the breakdown of macronutrients through cellular respiration. Carbohydrates, fats, and proteins are metabolized into glucose, fatty acids, and amino acids, respectively, through digestive processes. These molecules are then further broken down in cells, releasing energy in the form of adenosine triphosphate (ATP).
Therefore, while diet Red Bull may make someone feel more alert or awake due to its stimulant content, it does not provide actual energy in the scientific sense. To obtain energy for the body, it is necessary to consume proper macronutrients through a balanced diet.