Problem 92 - Chemistry Matter and Change

Question

Write balanced equations for photosynthesis, cellular respiration, and the hydrolysis of lactose.

Step-by-Step Solution

Answer

The balanced equations for the given reactions are: 1. Photosynthesis: \( 6CO_{2} + 6H_{2}O \xrightarrow{\textit{light}} C_{6}H_{12}O_{6} + 6O_{2} \) 2. Cellular Respiration: \( C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O + \textit{Energy(ATP)} \) 3. Hydrolysis of Lactose: \( C_{12}H_{22}O_{11} + H_{2}O \xrightarrow{\textit{lactase}} C_{6}H_{12}O_{6} + C_{6}H_{12}O_{6} \)

Step 1: 1. Photosynthesis

Photosynthesis is the process by which plants, algae, and some bacteria convert carbon dioxide and water into glucose and oxygen using sunlight as energy. The balanced equation for photosynthesis is: \[ 6CO_{2} + 6H_{2}O \xrightarrow{\textit{light}} C_{6}H_{12}O_{6} + 6O_{2} \]

Step 2: 2. Cellular Respiration

Cellular respiration is the process by which organisms convert glucose and oxygen into carbon dioxide, water, and energy in the form of ATP (adenosine triphosphate). The balanced equation for cellular respiration is: \[ C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O + \textit{Energy(ATP)} \]

Step 3: 3. Hydrolysis of Lactose

Lactose, a disaccharide, is made up of two monosaccharides, glucose and galactose. The hydrolysis of lactose occurs in the presence of water and an enzyme called lactase. In this reaction, lactose is broken down into glucose and galactose. The balanced equation for the hydrolysis of lactose is: \[ C_{12}H_{22}O_{11} + H_{2}O \xrightarrow{\textit{lactase}} C_{6}H_{12}O_{6} + C_{6}H_{12}O_{6} \]

Key Concepts

Photosynthesis

Photosynthesis is a fascinating process that enables plants, algae, and some bacteria to harness the energy from sunlight to create their own food. This process takes place in the chloroplasts of plant cells and involves the transformation of light energy into chemical energy.
During photosynthesis, carbon dioxide (\(CO_2\)) and water (\(H_2O\)) are converted into glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)).

• Glucose is a sugar that serves as food and energy storage for plants.
• Oxygen is released as a by-product, which is crucial for the survival of most living organisms on earth.

The balanced chemical equation for photosynthesis is:\[6CO_{2} + 6H_{2}O \xrightarrow{\(\textit{light}\)} C_{6}H_{12}O_{6} + 6O_{2}\]This equation depicts the necessary proportions of reactants and products involved in photosynthesis. It is essential to have exactly six molecules of carbon dioxide and six molecules of water to produce one molecule of glucose and six molecules of oxygen. Understanding this equation helps us appreciate the intricate balance and efficiency of nature's "food production."

Cellular Respiration

Cellular respiration is the process through which cells convert biochemical energy from nutrients into the energy currency of cells known as ATP (adenosine triphosphate). This process occurs in the mitochondria of cells.
Glucose (\(C_6H_{12}O_6\)) and oxygen (\(O_2\)) are the main inputs of cellular respiration, and these are broken down into carbon dioxide (\(CO_2\)), water (\(H_2O\)), and energy.

• ATP provides the energy necessary for various biological functions, such as muscle contractions and cell division.
• Carbon dioxide is released as a waste product, which is exhaled by animals.

The balanced equation for cellular respiration is:\[C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O + \(\textit{Energy(ATP)}\)\]It's fascinating to note that this process is essentially the reverse of photosynthesis. The cycle of these two reactions maintains a balance of energy and carbon dioxide and oxygen in the environment. Cellular respiration illustrates how organisms use oxygen and glucose to maintain life activities and energy production.

Lactose Hydrolysis

Lactose hydrolysis is the chemical reaction responsible for the breakdown of lactose, a sugar found in milk, into its constituent monosaccharides. This simple reaction plays a vital role in digestion, especially for individuals who consume dairy products.
Lactose (\(C_{12}H_{22}O_{11}\)) is a disaccharide made up of glucose and galactose. During hydrolysis, lactose reacts with water (\(H_2O\)) in the presence of the enzyme lactase, resulting in the production of glucose and galactose (\(C_6H_{12}O_6\)).

• The presence of the enzyme lactase ensures that the reaction occurs quickly and efficiently.
• This process allows the body to absorb and utilize the monosaccharides for energy.

The balanced chemical equation for the hydrolysis of lactose is:\[C_{12}H_{22}O_{11} + H_{2}O \xrightarrow{\(\textit{lactase}\)} C_{6}H_{12}O_{6} + C_{6}H_{12}O_{6}\]Lactose intolerance occurs when individuals have insufficient levels of lactase, leading to difficulties in digesting lactose. Understanding this equation highlights the importance of enzymes in facilitating biochemical reactions in our bodies.