Structure of Cell

Introduction:

Cells are the basic, structural, and functional unit of all living organisms. The small, tiny bacteria and the large elephant are made of cells. All cells need the energy to carry out life processes. All cells have structures called organelles that work together to help them perform life processes and to keep the cell alive. 

Cells in different organisms have differences also; plant cells need to store a lot of water because they do not move. Plants usually do not eat other living things, so their cells need special organelles to produce their food. Unlike plants, animals move around. They require cells that are flexible and show movement. Animals do not have cells that produce their food because they get their energy by feeding on other living things. 

What organelles are present in animal cells? 

Cell membrane: The cell membrane is present in all animal cells. It covers the cell externally somewhat the same way your skin wraps around you. It gives the cell shape and regulates what moves in and out of the cell. It is mainly composed of phospholipids, proteins, and carbohydrates. It is selective, i.e., it allows only certain materials to enter and exit the cell. 

Cytoplasm: Inside the cell membrane is the cytoplasm. It is a jelly-like substance in which organelles of the cells are embedded. It helps the organelles to carry out various jobs in the cell. The cytoplasm is constantly moving through the cell in a stream-like motion. 

Nucleus: The nucleus is a large spherical structure located in the center of the cell. It has a double membrane with pores to allow certain materials to pass inside and outside. The nucleus controls all the activities in the cell, and the content chromosomes and DNA that carry genetic materials are called genes. The nucleus tells the cell when it is time to break down food, to grow, to move, and even when it is time for the cell to die. 

Some organisms, especially bacteria, which have nuclear material without nuclear membrane and lack double-membrane organelles, are termed prokaryotic cells. Examples are bacteria and blue-green algae. The organisms that have a well-developed nucleus and double membrane-bound organelles are called eukaryotes. 

Mitochondria: Mitochondria are oval-shaped sacs in the cell. These sacs have a folded inner membrane that gives the mitochondria more surface area and allows them to do more work for the cell. Mitochondria break down food and convert it into energy for the cell to use, and that is why it is also called the powerhouse of the cell. The more energy a cell requires, the more mitochondria that cell will have; very active cells, such as human liver cells, need a lot of mitochondria. 

Vacuole: Vacuoles store water, food, and waste. The nucleus passes signals to vacuoles to release whatever it is holding. It is very small in animal cells, and sometimes it is absent.   

What organelles are present in the plant cell? 

Plant cells have almost the same organelles as animal cells. They have some extra structures that animal cells do not have.   

Cell wall: Plant cells have an extra protective layer outside the cell called the cell wall. The cell wall is composed of a hard, specialized sugar called cellulose. Cellulose protects and provides support for the plant cells and gives them their shape. The cell wall lets food and waste move inside and outside of the cell. 

Chloroplast: Most of the plant cells contain chloroplasts that convert energy from sunlight into food and are responsible for photosynthesis. Chloroplasts are green in color because they have a green chemical called chlorophyll. 

Vacuole: Unlike animal cells, plant cells have one large central vacuole that stores water and provides support. The vacuoles release water, which causes the vacuoles to shrink, making the cells smaller and the plant bend over. Once you water the plant, the vacuoles have water again, and the plant stands back up. 

Summary

• Cells are the basic, structural and functional unit of all living organisms. The small, Tiny bacteria and the large elephant are made of cells.
• The cell membrane is present in all animal cells. It covers the cell externally somewhat the same way your skin wraps around you.
• The nucleus is a large spherical structure located in the center of the cell. It has a double membrane with pores to allow certain materials to pass inside and outside.
• Mitochondria are oval-shaped sacs in the cell. These sacs have a folded inner membrane that gives the mitochondria more surface area and allows them to do more work for the cell.
• Vacuoles store water, food, and waste.
  Plant cells have an extra protective layer outside of the cell called the cell wall. The cell wall is composed of a hard, specialized sugar called cellulose.
• Most of the plant cells contain chloroplasts that convert energy from sunlight into food and are responsible for photosynthesis.