explain the typical cell part wise and clearly
Answers
Answer:
CLEARLY AND WISELY
Explanation:
Trees in a forest, fish in a river, horseflies on a farm, lemurs in the jungle, reeds in a pond, worms in the soil — all these plants and animals are made of the building blocks we call cells. Like these examples, many living things consist of vast numbers of cells working in concert with one another. Other forms of life, however, are made of only a single cell, such as the many species of bacteria and protozoa. Cells, whether living on their own or as part of a multicellular organism, are usually too small to be seen without a light microscope.
Cells share many common features, yet they can look wildly different. In fact, cells have adapted over billions of years to a wide array of environments and functional roles. Nerve cells, for example, have long, thin extensions that can reach for meters and serve to transmit signals rapidly. Closely fitting, brick-shaped plant cells have a rigid outer layer that helps provide the structural support that trees and other plants require. Long, tapered muscle cells have an intrinsic stretchiness that allows them to change length within contracting and relaxing biceps.
Still, as different as these cells are, they all rely on the same basic strategies to keep the outside out, allow necessary substances in and permit others to leave, maintain their health, and replicate themselves. In fact, these traits are precisely what make a cell a cell.
What Defines a Cell?
An illustration shows a cross section of a plasma membrane with three different transport proteins arranged across the phospholipid bilayer. Each protein acts as a pore, as shown by an arrow through the center of it. Small beads representing molecules are hovering near the proteins, showing higher concentration either outside of the membrane or inside of it. The transport proteins are therefore regulating concentrations of molecules inside the cell, by controlling the passage of molecules through pores.
Figure 1: Transport proteins in the cell membrane
A plasma membrane is permeable to specific molecules that a cell needs. Transport proteins in the cell membrane allow for selective passage of specific molecules from the external environment. Each transport protein is specific to a certian molecule (indicated by matching colors).
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Cells are considered the basic units of life in part because they come in discrete and easily recognizable packages. That's because all cells are surrounded by a structure called the cell membrane — which, much like the walls of a house, serves as a clear boundary between the cell's internal and external environments. The cell membrane is sometimes also referred to as the plasma membrane.
Cell membranes are based on a framework of fat-based molecules called phospholipids, which physically prevent water-loving, or hydrophilic, substances from entering or escaping the cell. These membranes are also studded with proteins that serve various functions. Some of these proteins act as gatekeepers, determining what substances can and cannot cross the membrane. Others function as markers, identifying the cell as part of the same organism or as foreign. Still others work like fasteners, binding cells together so they can function as a unit. Yet other membrane proteins serve as communicators, sending and receiving signals from neighboring cells and the environment — whether friendly or alarming (Figure 1).
Within this membrane, a cell's interior environment is water based. Called cytoplasm, this liquid environment is packed full of cellular machinery and structural elements. In fact, the concentrations of proteins inside a cell far outnumber those on the outside — whether the outside is ocean water (as in the case of a single-celled alga) or blood serum (as in the case of a red blood cell). Although cell membranes form natural barriers in watery environments, a cell must nonetheless expend quite a bit of energy to maintain the high concentrations of intracellular constituents necessary for its survival. Indeed, cells may use as much as 30 percent of their energy just to maintain the composition of their cytoplasm.
What Other Components Do Cells Have?
As previously mentioned, a cell's cytoplasm is home to numerous functional and structural elements. These elements exist in the form of molecules and organelles — picture them as the tools, appliances, and inner rooms of the cell. Major classes of intracellular organic molecules include nucleic acids, proteins, carbohydrates, and lipids, all of which are essential to the cell's functions.
Then coming to the other cell organelles- both plant and animal cells have MITOCHONDRIA which manufacture energy in the form of ATP (Adenosine TriPhosphate) and are thus called power houses of the cell... there are RIBOSOMES, which are membrane less organelles and synthesise proteins...then there are VACUOLES which are large and permanent in plant cells and temporary and small in animal cells and are mainly responsible for osmoregulation and storage of food.....LYSOSOMES are also present which are the suicide bags of the cell as they secrete enzymes for the digestion of extracellular substances, intracellular substances and even other cell organelles....then a network of tubular filamentous structures is present in the cell which is the ENDOPLASMIC RETICULUM and may or may not contain ribosomes on it, it is responsible for protein or lipid synthesis....the GOLGI BODIES present in the cell is formed from the rough endoplasmic reticulum (which contains ribosomes) and plays a major role in secretion of cell wall material (pectin, lignin, etc) and formation of cell wall, cell plate, acrosome and carbohydrate compounds...then there are CYTOSKELETONS in some cells which provide the basal structure for formation of CILIA and FLAGELLA and centrosomes which help in movement and locomotion (made of protein molecules which show 9+2 arrangement ie 9 protein triplets are peripherally located and 2 are central)...
Now finally coming to PLASTIDS, CELL WALL AND CENTROSOME:
Plastids and Cell wall are present only in plant cell. Plastids are of three types-leucoplast (colourless and stores carbohydrates in amyloplasts, fats in elaioplasts and proteins in aleuroplasts), chromoplast (which contains carotene(orange) and xanthophyll(yellow) for fruit and flower colouration and chloroplast (which contain chlorophyll also and are responsible for photosynthesis - manufacture of food in plants). Cell wall has three layers- middle lamella, primary cell wall and secondary cell wall.
Centrosomes are present in animal cells only and show 9+0 arrangement and have no membrane...they help in DNA replication and transfer of genes.
This was the description of a typical cell and I hope you will mark it as the brainliest! Thanks! :)