Advantages And Disadvantages Of Cell Membranes

Essentially, the nucleus is vital for the cell’s survival. The nucleus controls and gives instructions to all organelles and inhabitants of the cell(Doc. 2). It is a dense, ball shaped configuration that contains the DNA of the cell.

Cells are a highly complex entity and is both structurally and functionally the basic unit of all living things. Cells are an important and vital part in order to sustain life. Cells are highly diverse and their specific roles are dependent on shape and internal composition. Cells are what carry out functions to promote life, including: reproduction, nutrient digestion, and metabolism. The cell has many components including the nucleus, cytoplasm, many organelles, and a plasma membrane. The nucleus contains all of the genetic material and genes, which are found in the DNA. The nucleus is the control center of the cell as it is key for cell reproduction. The nucleus is surrounded in a membrane called the nuclear envelope for protection and regulation of materials in and out of the nucleus. Cytoplasm is what all of the cell contents is referred to outside of the nucleus. This includes all the high specific metabolic machinery called organelles. A list of organelles include: Ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria, and centrioles. Ribosomes are free floating spherical bodies of RNA and proteins which are the site for protein synthesis. Endoplasmic reticulum is broken into two structures, the rough and smooth endoplasmic reticulum. Rough ER provides area for storage and transport of proteins

Nucleus – The nucleus is the largest organelle in the cell. It acts as the control system for almost all the activities of the cell. It stores the cell 's hereditary material, or DNA

To begin, the animal cell is the cell that is in humans or other animals. Although the nucleus is in both animal and plant cells (Doc. 1), it is more crucial in an animal cell (OI). The nucleus is the “big brain,” and “controls everything” (Doc. 3). Like most organelles, the nucleus has a membrane protecting it (Doc. 1). On the other hand, it has multiple membranes protecting it unlike other organelles (OI). Unquestionably, the big brain and controller is most definitely vital because without a controller everything would be crazy.

Every cell membrane incorporates a fluid mosaic model. The “mosaic” of protein molecules embedded in a lipid bilayer. It’s fluid as most proteins and lipid molecules drift through it. The membrane consists of a phospholipid bilayer embedded with various proteins. The proteins help to get polar/hydrophilic molecules through the plasma membrane. Polar molecules have difficulty passing thru the hydrophilic membrane. Nonpolar molecules however, easily pass thru. The proteins can be integral proteins, meaning they go all the way through the lipid bilayer or peripheral proteins that sit on the hydrophilic outer layer and wait for something to happen. The layers are somewhat fluid, allowing the proteins to move across them. See diagram below.

Cell membrane is a selective boundary composed of a unique phospholipid bi-layer structure consisting of lipids, proteins and carbohydrates. This structure regulates the import and export to maintain homeostasis condition inside the cell. (Knox et al., 2014) The plasma membrane is referred as a fluid mosaic which also has selective permeability. The permeability of the membrane can be varied depending on the external conditions. (Mitchel, 2015)

The cellular membrane is a selectively-permeable phospholipid bilayer that also contains embedded proteins as well as cholesterol which gives the membrane its fluidity. A phospholipid molecule has two ends, a head and tail; the head is hydrophilic, meaning it is attracted to water molecules, while the tail end is hydrophobic and not attracted to water molecules. Selectively-permeable means it will let certain molecules into the cell, while making sure certain particles stay out. The proteins located in the membrane take over as the mechanism to move different molecules in and out of the cell.(“What is a semipermeable membrane?, 2015”)

The largest organelle in the eukaryotic cell;the nucleus, is arranged as linear instead of circular DNA molecules, which also holds the cell's genetic information ( Campbell et al., n.d.). Eukaryotic cells also contain a variety of membrane-enclosed organelles, prevalent in the cytoplasm.

The largest organelle, the nucleus is a membrane-bound organelle that contains the vast majority of the cell’s DNA. The nucleus is considered the defining feature of a eukaryotic cell because its presence separates eukaryotes from the more ancient prokaryotic cell. The nucleus is often referred to as “the control center” of the cell because the DNA that it contains directs all aspects of cellular function (18). While most cells only have one nucleus, some cells (red blood cells) lack a nucleus and are therefore unable to divide and produce daughter cells. In humans, some types of skeletal muscle cells have multiple nuclei during their development; however multinucleated cells can also be associated with inflammation (19) and tumor development (20).

The cell membrane (also known as the plasma membrane) is a “thin semi-permeable membrane that surrounds the cytoplasm of a cell” (Bailey, 2010). The purpose of cell membrane is to serve as a barrier or gate keeper. Some molecules are able to diffuse across the lipid bilayer while others are prohibited from entering the cell. (The Editors of Encyclopædia Britannica, 2016). Allowing only specific molecules to enter the cell and keeping others out of the cell is what gives the cell membrane the “semipermeable” characteristic (Bailey,

The cell membrane surrounds the cytoplasm of a cell and is the barrier as to what can and cannot pass through the cell. The cell membrane acts as a barrier and is one of the many key factors for supporting life, without it diffusion and osmosis would not be able to occur. The barrier is selectively/partially permeable and regulates what enters and exits the cell, therefore facilitating the transport of materials needed for survival. There is two processes in which substances are carried across the membrane, either passive transport or active transport. Passive transport transpires without the input of cellular energy albeit Active Transport requires cells to expend energy to move the substance across the barrier. The cell membrane also maintains cell potential.

This micrograph demonstrates that these organelles is a Nucleus because by looking at this, I can see the dual membrane structures. I can see that nucleus having a sphere-shaped organelle found in eukaryotic cells. Furthermore, I can see that it contains genetic material where it is darkening. In addition, I am also able to see the endoplasmic reticulum. This overall proves me that it is nucleus.

Neurons are throughout our entire body and are what allow our central nervous system and brain communicate with your whole body. Nerve impulses among motor neurons are what allow our bodies to move when we want to. A nerve impulse is an electrical signal that travels down the axon to transmit information to other neurons to allow movement. In order for a nerve impulse to be generated, a stimulus must be strong enough to cause an “all-or-nothing” response. If the signal is strong enough the reach the neuron’s threshold, then the neuron will “fire”, or send the impulse down the axon. Before this happens, the resting neuron must be polarized by having different charges on either side of the cell membrane. This is because the outside of the cell membrane is more positive due to the presence of sodium ions while the inside is more negative due to the presence of potassium ions. Normally the resting neuron has an electrochemical value of -70 mV. In order for the electrical balance to remain stable and for the cell the maintain homeostasis, the sodium/potassium moves sodium ions out of the cell and potassium ions into the cell using ATP. When the nerve impulse is generated the balance that was created by the cell membrane is reversed, causing sodium ions to go into the cell and potassium ions to leave the cell. The cell is now in a depolarized state due to a more positive charge inside the cell and a more negative charge outside the cell. This depolarization causes the

Nucleus- “the brain” or control center of the cell. The Nucleus, a membrane-bound structure of a cell, plays two crucial roles in controlling the cell. The nucleus carries the cell's genetic information that determines if the organism will develop, for instance, into a tree or a human; and it directs most cell activities including growth, metabolism, and reproduction by controlling protein synthesis. The presence of a nucleus distinguishes the more complex eukaryotic cells of plants and animals from the simpler prokaryotic cells of bacteria and cyanobacteria that lack a nucleus. The nucleus is the most predominate structure in the cell. It is typically round and occupies 10% of the cells total volume. The nucleus is wrapped in a

In regards to their basic structure, according to the SEER Training website, “cells consist of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm.” (Training.seer.cancer.gov, 2017) This is true for animal cells however plant cells contain a fourth part which is known as the cell wall, it is located on the outside of the cell membrane and allows the cell to keep its rigid shape. It should also be known that there are types of cells that do not contain a nucleus, these are called prokaryotic cells and generally still have the same characteristics as cells that do have a nucleus which are known as eukaryotic cells. (Study.com, 2017) As seen in Figure 1 cells also contain organelles which keep the cell alive and allow it to function effectively.The cytoplasm of the cell which resides between the cell membrane and the nucleus is a gel-like liquid filling the inside of the cell. The cytoplasm allows the cell to have shape and allows the cell 's organelles to move around the cell as needed and function correctly. The nucleus is widely considered to be the control center or