How do food, oxygen and water enter a cell?
Osmosis
http://en.wikipedia.org/wiki/Osmosis
http://www.beaconlearningcenter.com/documents/1965_3263.pdf
Mitochondria becaus that's where alll the oxygen, water, and food is stored
Food, oxygen, and water enter a cell through different processes and mechanisms. Let's explore how each of these substances enters a cell:
1. Food:
Food molecules are typically too large to pass directly through the cell membrane, so they need to be broken down into smaller molecules that can be transported into the cell. This process begins in the digestive system, where food is broken down into smaller molecules through processes like chewing, enzymatic digestion, and absorption. Once the food is broken down, it is absorbed into the bloodstream and transported to cells throughout the body. In the case of single-celled organisms, such as bacteria, they engulf the food particles in a process called endocytosis, where the cell membrane surrounds and engulfs the food particles, forming a food vacuole. The vacuole then fuses with lysosomes, which contain digestive enzymes, to break down the food into smaller molecules that can be used by the cell.
2. Oxygen:
In multicellular organisms, oxygen enters cells through the process of respiration. Oxygen is inhaled into the lungs and diffuses into the bloodstream. It binds to hemoglobin in red blood cells and is transported to cells throughout the body. At the cellular level, oxygen diffuses across the cell membrane into the cytoplasm, where it participates in cellular respiration—specifically, the process of aerobic respiration. Inside the mitochondria, oxygen is used to break down glucose (from food) and produce energy in the form of ATP.
3. Water:
Water molecules are small and polar, so they can pass through the cell membrane by simple diffusion. Cells contain aquaporin proteins, which act as channels to facilitate the movement of water across the cell membrane. Additionally, water can enter cells through processes such as osmosis (the movement of water from an area of low solute concentration to an area of high solute concentration) and active transport (requiring energy to move water across the membrane against its concentration gradient).
In summary, food enters a cell through digestion and absorption, oxygen enters through respiration, and water enters through diffusion, osmosis, and active transport. These processes ensure that cells have the necessary nutrients and resources for their survival and functioning.