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 the increased mass in a corn plant over the course of a summer is photosynthesis. Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to produce glucose (a type of sugar) and oxygen. Glucose is then converted into various molecules, such as cellulose, starch, and other carbohydrates, which are used for energy production and growth.
The process responsible for the gain in mass is a combination of cellular respiration and plant growth. During cellular respiration, plants break down the glucose they produced through photosynthesis to release energy for various metabolic processes. This energy is utilized to power growth, reproduction, and other essential plant functions. As the plant grows, it incorporates these newly synthesized molecules into the various tissues and structures, leading to an increase in overall biomass.
In summary, the increased mass in a corn plant over the summer is primarily a result of photosynthesis, where the plant converts sunlight, water, and carbon dioxide into glucose. The glucose is then used for energy through cellular respiration and for building new plant material, leading to the overall gain in mass.
2. Drinking diet Red Bull does not provide actual energy to the body. While energy drinks like Red Bull may contain substances like caffeine and other stimulants that can give the sensation of increased energy or alertness, they do not provide the body with the kind of energy that is required for physiological processes.
Energy, in the scientific sense, refers to the capacity to do work. The energy needed by our bodies is derived from the calories we obtain from food, specifically carbohydrates, proteins, and fats. These macronutrients are broken down through digestion and their energy content is used in cellular processes to fuel bodily functions, growth, and repair.
Drinks like Red Bull may contain caffeine, which is a central nervous system stimulant that can make people feel more awake and alert. However, caffeine does not provide actual energy to the body in terms of fueling metabolic processes. It simply affects the activity of the nervous system.
Therefore, while drinking diet Red Bull may give a temporary feeling of increased energy or alertness due to the presence of stimulants, it does not provide the necessary energy for the body's daily functioning. Proper nutrition and a balanced diet are essential for obtaining the energy needed for physiological processes.