Chemical and Physical Changes Quiz

Food and Respiration Processes

Milk at Room Temperature

• When milk is left at room temperature during summers, it can spoil quickly due to the growth of bacteria and other microorganisms.
• The ideal temperature for milk storage is between 3°C and 5°C, but at room temperature (around 20°C to 30°C), the bacteria can multiply rapidly, leading to curdling, souring, and an unpleasant smell.

Fermentation of Grapes

• When grapes get fermented, they undergo a process of anaerobic respiration, where yeast consumes the sugars present in the grapes, producing ethanol and carbon dioxide as byproducts.
• This process is commonly used in the production of wine, where the fermentation process is controlled to produce the desired flavor and texture.

Digestion in the Human Body

• When food gets digested in our body, it breaks down into smaller molecules that can be absorbed and utilized by the body for energy, growth, and repair.
• The digestion process involves mechanical and chemical breakdown of food, involving enzymes, acids, and other digestive juices in the mouth, stomach, and small intestine.

Respiration

• When we respire, our body takes in oxygen and releases carbon dioxide through the process of cellular respiration, where energy is generated from the breakdown of glucose and other nutrients.
• This process involves the exchange of gases between the lungs and the atmosphere, and is essential for the survival of all living organisms.