Essay on Make-up of Life-giving Cells

2) The mRNA exits through the pores in the nuclear envelope and travels to the cytoplasm, where it then binds to ribosomes.

Inside the nucleus is the nucleolus which produces ribosomes. The ribosomes then transport out of the nucleolus and to the rough endoplasmic reticulum for a process called protein synthesis. (Plant Cell Anatomy, n.d.)

The nucleus is the control centre of a cell. It contains genetic material such as DNA and controls the cell's growth and

Nearly all animal cells have a nucleus, with the only exception being the red blood cell. The nucleus has two major functions, which are housing the DNA and controlling the cell’s activities. In the centre of the nucleus is the nucleolus. This doesn’t have a membrane, but holds itself together. In the nucleolus, ribosomes are created through the mixture of RNA and proteins. These proteins are originally found in the cytoplasm, outside the nucleus, but they travel through the pores in the nuclear envelope, through the chromatin and into the nucleolus. The structure of the nucleolus allows easy

The cell’s nonmembranous organelles include the cytoskeleton, microvilli, centrioles, cilia, ribosomes, and proteasomes. Membranous organelles include the endoplasmic reticulum, the Golgi apparatus, lysosomes, peroxisomes, and mitochondria.

It supports the cell’s structure and helps maintain the cell’s shape. The care center and the ribosomes both support the cell/zoo. The care center is the animals’ main source of proteins and vegetables. They mix different types of foods together depending on what the head office thinks is best for the animals.

Next, SMS and cells have “ribosomes.” The function of the ribosome is to make proteins for the cell. The school has several cooks. They make food (and proteins) for students.

Breaking down an organism leads scientists to identify cells. A group of cells create tissues, tissues combined are organs, and organs and their functions make up systems. Basically, cells make up living organisms. There are 2 kinds of cells: Prokaryotic and Eukaryotic. Within a prokaryotic, it doesn’t contain a DNA bounded nucleus; however, a eukaryotic cell does. Though the prokaryotic cell differs from a eukaryotic cell, they share a cell membrane. The cell membrane is composed of a phospholipid bilayer and proteins, which makes it selectively permeable. It is located outside of the cytoplasm and controls the movement of substances in and out of the cell. Its basic function is to protect the cell from its surroundings by selecting what can enter and exit the cell.

The mitochondria is commonly know as the “powerhouse” of the cell. It is a small structure in the cell that are made up of two membranes. Cellular respiration is the job of the mitochondria. Which means it takes in nutrients from the cell, breaks it down and turns it into energy. Then the energy is used by the cell for other functions. (“Gale Encyclopedia...”,2010)

Organisms are made up of cells which were considered as the basic unit of life. After the invention of microscope, Robert Hooke first discovered cells by looking at a dead cell from an oak tree. His finding brought the study of cell biology. According to the cell theory formulated by lots of scientists, all living organisms are composed of at least one cell which is the basic unit of life, and all cells come from pre-existing living cells.

Microtubules are assembled at the microtubule organizing center (MTOC), which consist of centrosomes surrounded by pericentriolar material (PCM) in animal cells. Nucleation, which is the initiation of microtubules, occurs at the MTOC and consists of 13 gamma-tubulin subunits forming an open ring where the first set of tubulin are added at the positive end (Tassins and Bornens, 1999). Growth of the microtubule consists of the polymerization, addition of tubulin dimers on the positive end near the cell periphery, faster than tubulin dimers can be lost at the minus end, which is attached to the centrosome toward the cell center.

I. Introduction: • The cell is the smallest basic element of all life, but it has incredible biological organization functions such as metabolism, growth, movement, reproduction, and heredity. A human cell has three major parts: the plasma membrane, the cytoplasm, and the nucleus. The plasma membrane is a partially permeable membrane which controls substances entering or leaving the cell. It also acts like a barrier blocking harmful things from entering the cell and lets nutrients in. There are two types of movement across the plasma membrane: passively or actively.

Many cells are filled with a complex network of tube like things known as the endoplasmic reticulum. The endoplasmic

In an animal cell, plasma membrane is the border surrounding the cell that allows the passage of enough oxygen, nutrients, and wastes (98). Cytoplasm is region between the cell membrane and the nucleus, and that is where we find various types of organelles of specific form and their tasks (98). The nucleus is an information center that contains most of the genetic information (DNA) and it controls the activities by creating messenger RNA (mRNA) so it can instruct protein synthesis (102). The nucleus’s outer layer is surrounded by nuclear envelope, which is a double membrane (inner and outer membrane (102). Furthermore, the nuclear envelope has pores that allow proteins, RNAs, etc. to enter or exit the nucleus (102). In other words, it is like a gate that controls passage area between the nucleus and cytoplasm. Moreover, within the nucleus there is another organelle called nucleolus where the ribosomal RNA (rRNA) is synthesized (102). Ribosomes are complexes that are made of rRNA and proteins inside of nucleolus (102-103). They help synthesize proteins, meaning that it helps create proteins in a cell. There are two types of ribosomes: free ribosomes and bound ribosomes. Most of the proteins are made by free ribosomes that functions within the cytoplasm (102). Whereas bound ribosomes are attached to the endoplasmic reticulum in order to make proteins that will go into the membrane, sent within certain organelles, or export of the cell (102-104). There are two types of

The cell membrane is made of phospholipids and proteins, like eukaryotic membranes, and controls the entry and exit of substances into and out of the cell. The mesosome is a tightly folded region of the cell membrane containing all the membrane-bound proteins required for respiration and photosynthesis. The flagellum is a rigid rotating helical-shaped tail used for propulsion. The motor is embedded in the cell membrane and is driven by a H+ gradient across the membrane. A clockwise rotation drives the cell forwards, while an anticlockwise rotation causes a chaotic spin.