Structure of cell

Cells are the fundamental units of life from which all other living things are made. They contain all the molecules and structures needed for individual cell survival and the survival of the organism as a whole. Different cells have different subcellular structures, but all eukaryotes contain the same three parts: the nucleus, the cell membrane, and the cytoplasm. Cells all contain the same three basic parts What is the Structure of Cells? All eukaryotic cells consist of three basic parts . These are the cell membrane, the nucleus, and the cytoplasm. The cell membrane surrounds the outside of the cell, the nucleus is found in the middle of the cell, and the cytoplasm fills the gap between the two. Buried in the cytoplasm are hundreds or thousands of subcellular structures called organelles. The fluid inside cells is known as the intracellular fluid (ICF), while the environment outside of the cell is referred to as the extracellular fluid (ECF). The Cell Membrane The cell membrane (AKA the plasma membrane) is a thin, flexible structure that surrounds the outside of the cell, creating a physical barrier between the cell interior and its external environment. It consists of a semipermeable lipid bilayer that regulates the passage of materials in and out of the cell. All cells are surrounded by a cell membrane The Cytoplasm The cytoplasm is a jelly-like goo that fills the interior space of the cell. It cushions and protects the cell organelles and is also where many of the cel...

3 Cell Structure You say “procaryote,” I say “prokaryote,” you say “eucaryote,” I say “eukaryote”….well, however, you spell them, it’s the next topic. Traditionally, cellular organisms have been divided into two broad categories, based on their cell type. They are either prokaryotic or eukaryotic. In general, prokaryotes are smaller, simpler, with a lot less stuff, which would make eukaryotes larger, more complex, and more cluttered. The crux of their key difference can be deduced from their names: “karyose” is a Greek word meaning “nut” or “center,” a reference to the nucleus of a cell. “Pro” means “before,” while “Eu” means “true,” indicating that prokaryotes lack a nucleus (“before a nucleus”) while eukaryotes have a true nucleus. More recently, microbiologists have been rebelling against the term prokaryote because it lumps both bacteria and the more recently discovered archaea in the same category. Both cells are prokaryotic because they lack a nucleus and other organelles (such as mitochondria, Golgi apparatus, endoplasmic reticulum, etc), but they aren’t closely related genetically. So, to honor these differences this text will refer to the groups as the archaea, the bacteria, and the eukaryotes and try to leave the prokaryotic reference out of it. Cell Morphology Cell morphology is a reference to the shape of a cell. It might seem like a trivial concept but to a cell it is not. The shape dictates how that cell will grow, reproduce, obtain nutrients, move, and it’s ...

\( \newcommand\) • 1. Description of Cell Structure and Function. Cells are fundamental to the study of biology. Every living thing is composed of cells, they are the building blocks of life. All cells share similar characteristics and can be defined by the cell theory. Cell Theory 1. All living things are composed of cells. 2. All cells arise from preexisting cells through cell division. 3. Cells contain hereditary material, which they pass to daughter cells during cell division. 4. The chemical composition of all cells is quite similar. 5. The metabolic processes associated with life occur within cells. All cells have a few basic features in common: 1. Plasma membrane: a selective barrier which encloses a cell (plant and bacteria cells also contain a cell wall). 2. Cytosol: located inside the plasma membrane, this is a jelly-like fluid that supports organelles and other cellular components. 3. Cytoplasm: the cytosol and all the organelles other than the nucleus. 4. Ribosomes: the organelles on which protein synthesis takes place. 5. DNA: the genetic material which is contained in one or more chromosomes. Despite the fact that all cells share the above characteristics, they can be remarkably different in size, shape and function. Prokaryotic and Eukaryotic Cells There are two major categories or types of cells: prokaryotic and eukaryotic. Figure\(\PageIndex\).plant cell(CC BY-NC-SA; Cell Structure and Function Tutorialby This tutorial was funded by the Title V-STEM Grant ...

The cell membrane surrounds every livingcell and delimits the cell from thesurrounding environment. It serves as a barrier to keep the contents of the cell in and unwanted substances out. It also functions as a gate to both actively and passively move essential nutrients into the cell and waste products out of it. Certain proteins in the cell membrane are involved with cell-to-cell communication and help the cell to respond to changes in its environment. cell, in −14 gram—equal to that of 8,000,000,000 hydrogen atoms. Cells of humans typically have a mass 400,000 times larger than the mass of a single mycoplasma bacterium, but even

Phospholipid Definition A phospholipid is a type of lipid molecule that is the main component of the cell membrane. Lipids are molecules that include fats, waxes, and some vitamins, among others. Each phospholipid is made up of two fatty acids, a phosphate group, and a glycerol molecule. When many phospholipids line up, they form a double layer that is characteristic of all cell membranes. Phospholipid Structure A phospholipid is made up of two fatty acid tails and a phosphate group head. Fatty acids are long chains that are mostly made up of hydrogen and carbon, while phosphate groups consist of a phosphorus molecule with four oxygen molecules attached. These two components of the phospholipid are connected via a third molecule, glycerol. Phospholipids are able to form cell membranes because the phosphate group head is hydrophilic (water-loving) while the fatty acid tails are hydrophobic (water-hating). They automatically arrange themselves in a certain pattern in water because of these properties, and form cell membranes. To form membranes, phospholipids line up next to each other with their heads on the outside of the cell and their tails on the inside. A second layer of phospholipids also forms with heads facing the inside of the cell and tails facing away. In this way, a double layer is formed with phosphate group heads on the outside, and fatty acid tails on the inside. This double layer, called a lipid bilayer, forms the main part of the cell membrane. The nuclear e...

Maskot / Getty Images Cells Cells are the smallest unit of life. To understand what a cell looks like, picture a chicken egg. It has an outer membrane (in the case of an egg, it's a hard shell, but most cells aren't like that); it's filled with nutrient-rich fluid (whites of the egg versus cytoplasm in a cell) and has a nucleus (egg yolk). Not all cells look alike. Nerve cells are long, thin and covered in myelin, natural insulation. Nerve cells conduct impulses, which are used to communicate. They're basically the telephone wires of the body, and they look the part. Muscle cells are thick and elongated, like live rubber bands. Red blood cells are flat and discoid-shaped. The shapes of the cells help them with their individual functions. Tissues When cells of a certain type are grouped together, the resulting structure is called tissue. There is muscle tissue, which is made of strands of muscle cells. Adipose tissue is a tissue comprised of fat cells (adipocytes). Connective tissue is a term used for various types of tough, fibrous matter like tendons or ligaments.