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Scientists have found the answer to a long-standing question about how food molecules travel through cells.
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Introduction: how does a food molecule travel through a cell?
A food molecule travels through a cell by first diffusing across the cell membrane. The cell membrane is made of lipids, which are nonpolar molecules. This means that the cell membrane is impermeable to most ions and polar molecules, including glucose. Once the food molecule has diffused across the cell membrane, it enters the cytoplasm, where it is transported to the mitochondria. The mitochondria are organelles that are responsible for cellular respiration, which is how cells convert food molecules into energy.
The cell membrane
In order to understand how a food molecule travels through a cell, we must first understand the cell membrane. The cell membrane is a lipid bilayer that separates the interior of the cell from its exterior environment. This membrane is made up of two types of molecules:
-Lipids: These are fats that make up the majority of the cell membrane.
-Proteins: These are large molecules that are embedded in the lipid bilayer.
The cytoplasm
Cytoplasm is the jelly-like substance in cells that contains the organelles. Food molecules cannot enter the cells without specific transport proteins that are located in the cell membrane. These transport proteins use energy from ATP to move the molecules across the cell membrane and into the cytoplasm.
The endoplasmic reticulum
The endoplasmic reticulum is a network of membranes that helps to move food molecules through the cell. The endoplasmic reticulum is made up of two parts: the rough endoplasmic reticulum and the smooth endoplasmic reticulum.
The rough endoplasmic reticulum is covered in ribosomes, which are responsible for making proteins. The proteins made by the ribosomes are then sent to the Golgi apparatus, where they are packaged and shipped out of the cell.
The smooth endoplasmic reticulum does not have ribosomes on its surface. Instead, it is involved in lipid (fat) metabolism and calcium storage. It also helps to detoxify the cell by breaking down harmful substances.
The Golgi apparatus
Once a food molecule is digested and absorbed into the bloodstream, it travels through the body to the cells that need it. How does it get there?
The Golgi apparatus is a cell organelle that packages and distributes molecules to different parts of the cell or to other cells. It is often described as a “post office” for the cell because it sorts and ships molecules where they need to go.
Molecules enter the Golgi apparatus through tiny pores in the cell membrane. They are then transported through the Golgi apparatus in vesicles, which are small sacs filled with fluid. The vesicles fuse with other vesicles and move through the Golgi apparatus until they reach the correct destination. Finally, the vesicles release their contents and return to the original starting point to pick up more molecules.
Lysosomes
Lysosomes are organelles in animal cells that function as the cell’s garbage disposal system. They are responsible for breaking down and recycling old or damaged cell parts, as well as any foreign material that enters the cell. Lysosomes work by engulfing the material to be broken down and then releasing enzymes that digest it. The enzymes in lysosomes are very powerful and can break down almost any type of molecule, including fats, proteins, and carbohydrates.
The cell wall
A cell wall is a semipermeable membrane that helps to protect and support the cell. When a food molecule enters the cell, it first passes through the cell wall. The cell wall is made up of cellulose, a type of carbohydrate, and it is here that the food molecule is broken down into smaller molecules. These smaller molecules then pass through the cell membrane and enter the cytoplasm, where they are used by the cell for energy.
Mitochondria
On the inner membrane of mitochondria are embedded proteins that form tiny pores. These pores, called mitochondrial protein pores, allow small food molecules to enter the mitochondria for cellular respiration. Proteins are made up of chains of amino acids, and the specific sequence of amino acids in a protein determines its particular function. The proteins in mitochondrial protein pores have a specific sequence of amino acids that allows them to form a pore.
Chloroplasts
Chloroplasts are organelles in a plant cell that are unique in that they have the ability to change light into chemical energy that can be used by plants to create glucose from carbon dioxide and water. This process is called photosynthesis and it is how plants get their energy. Chloroplasts are able to do this because they have a molecule called chlorophyll.
Chlorophyll captures the energy in sunlight and uses it to stimulate a chemical reaction in the chloroplast. In this reaction, carbon dioxide and water are combined to create glucose. The glucose is then used by the plant for energy.
The vacuole
A vacuole is a membrane-bound organelle found in all plant and fungal cells and some protist, animal, bacterial cells. Vacuoles are essentially storage compartments within the cell, and they vary vastly in size and function depending on the type of organism. In plant cells, vacuoles store water, ions, and other molecules that help to maintain the cell’s structure and function. Animal cells typically have only one small vacuole that stores water, ions, and waste products. Some bacteria also have vacuoles that help them to survive in harsh environments by storing nutrients or releasing toxins.
