Title : With the aid of diagrams, compare the structure and function of prokaryotic and eukaryotic cells
All the living beings are made up of cells. They contain nucleus, which controls and performs their activities. The cells are divided into the two main categories depending on whether they contain nucleus or not. They are:
Prokaryotic cell Eukaryotic cell Simplest and ancient
Complex and evolved from prokaryotes
Single-cell
Single - celled or multicellular
Lacks nucleus
Contains nucleus
Contains cell wall (peptidoglycan)
Contains cellulose cell wall only in plant cells
Small ribosomes scattered throughout the cytoplasm. No mitochondria hence respiration takes place on an infolding of the cell membrane
They release enzyme called carbonic anhydrase which allows water into the blood to carry carbon dioxide to the lungs where it is expelled. Also, they aid in controlling the pH of the blood by acting as an acid-base buffer. Sperm Cells
Structure:
Sperm cell is a male reproductive cell which is formed in male reproductive system. They are very tiny about 0.002 inches long, because they contain a long tail-like flagella. The main function of sperm cell is to carry the genetic information of male parent and form a new embryo when combined with an egg cell. The shape of the sperm is quite simple, like a structure of snake which comprises of a small ovular head, neck, middle piece and tail.
Head :
It is spherical in shape which mainly consists of a large nucleus and a cap-like structure called acrosome. The nucleus contains DNA and nuclear proteins which is responsible for the transmission of hereditary characters from the male. The acrosome is filled with digestive enzymes (hyaluronidase and acrosin) which aids in sperm penetrating into ovum.
The building of the grocery store is like the cell membrane, because it gives it structure and keeps everything inside safe. The security guard of the front door in the grocery store is like the cell membrane, because it says what can come in and out of the cell. The boss of the store is like the nucleus, because they tell the employes what to do and what needs to be done. The floors of the grocery store is like the cytoplasm, because it hold everything in it place, where it need to be. The illes in the store is
Question 1: Briefly describe, in 500 words or less, the normal structure and function of your chosen cell type. In your answer, discuss specific features in your chosen cell type, including cell organelles.
There are many different cells that do many different things. But all of these cells fall into two categories: prokaryotic and eukaryotic cells. Eukaryotic cells contain a nucleus and are larger in size than prokaryotic cells. Prokaryotic cells do not contain a nucleus, are smaller and simpler than eukaryotic cells. Two of their similarities are they both have DNA as their genetic material and are covered by a cell membrane. Two main differences between these two cells are age and structure. It is believed that prokaryotic cells were the first forms on earth. They are considered primitive and originated approximately 3.5 billion years ago. Eukaryotic cells have only been around for about a billion years. There is strong evidence that suggests eukaryotic cells may be evolved from groups of prokaryotic cells that became interdependent on each other (Phenotypic analysis. (n.d.).
Eukaryotic Cells are Deemed as a Result of the Evolution of Symbiotic Prokaryotes Both Prokaryotic and Eukaryotic cells over time have sustained very dynamic changes from one another. More specifically we have seen the appearance of a more complicated and organized cell structure, the nucleus. However the big question amongst scientists today is how did these changes first occur? A fundamental concept of this evolution is the belief in the natural progression 'from the simple, to the more complex.' However one popular theory that argues that Prokaryotic symbiosis was responsible for forming the Eukaryotic nucleus is the 'Endosymbiotic Theory' this theory was first proposed by a former Boston University Biologist known as Lynn Margulis in the 1960's.
In 1871 Hugo de Vries cell membrane permeability for ammonia and glycerol, this was leading upto the first successful X-ray study by Bernal and Crowfoot in 1934 of the globular protein pepsin, however even though it shows water covering the protein surface, it doesn’t show it in high resolution. Many years has past with more testing and experiments but it wasn’t until 1925 when E, Gorter and F, Grendel proposed the phospholipid layers in the cell membrane which resulted in them doing first bilayer structure experiment test, obtaining this by measuring the size of water surface that phospholipids taken from red blood cell can cover, the area in which it covered was nearly twice as much as the total area of red blood cells used to extract the phospholipids, as a result this ended up being a lucky find in bilayer structure and with more accurate measuring and due to the presence of proteins within the membrane the ratio of the two surfaces wouldn’t of been 2:1, although this original finding was not able to be duplicated as stimulated membrane research, it steered it in the right direction. In 1985 M. Diesenhofer, R.Huber and H. Michel show the structure of the membrane protein in high resolution, showing alpha helical transmembrane segments.
Allows air to flow though the larynx and bronchi and divides air flow between the lungs and bronchioles.
The cell plasma membrane, a bilayer structure composed mainly of phospholipids, is characterized by its fluidity. Membrane fluidity, as well as being affected by lipid and protein composition and temperature (Purdy et al. 2005), is regulated by its cholesterol concentration (Harby 2001, McLaurin 2002). Cholesterol is a special type of lipid, known as a steroid, formed by a polar OH headgroup and a single hydrocarbon tail (Wikipedia 2005, Diwan 2005). Like its fellow membrane lipids, cholesterol arranges itself in the same direction; its polar head is lined up with the polar headgroups of the phospholipid molecules (Spurger 2002). The stiffening and decreasing permeability of the bilayer that results from including cholesterol occurs due to its placement; the short, rigid molecules fit neatly into the gaps between phospholipids left due to the bends in their hydrocarbon tails (Alberts et al. 2004). Increased fluidity of the bilayer is a result of these bends or kinks affecting how closely the phospholipids can pack together (Alberts et al. 2004). Consequently, adding cholesterol molecules into the gaps between them disrupts the close packing of the phospholipids, resulting in the decreased membrane fluidity (Yehuda et al. 2002).
You begin life as a single cell, formed when the sperm fertilises the egg. Out of all the sperm it only takes one sperm and one egg to fertilise at conception. This is called fertilization; which takes place in the Fallopian tube, the fertilized egg then divides
its original shape and shape. Within the phospholipid bi-layer there are proteins, and these. proteins are made up of polypeptide chains which are joined together. by hydrogen, hydrophobic and peptide bonds. Once the temperature has increased above 40°C the molecules vibrate so energetically that these bonds break easily and therefore create holes within the cell wall.
The nucleus is one of the most important organelles in a eukaryotic cell. The shape of the nucleus is generally spherical, it should be oval, disc formed reckoning on the sort of cell. The nucleus was found by Robert Brown in 1831 while he was looking at orchids under a microscope. He discovered a blurred area in the cells of the flowers and called it the areola or the nucleus.
Prescott, Harley & Klein (1990) describe bacteria as prokaryotic cells (cells that lack a true membrane enclosed nucleus). Bacteria are both small and simple in structure; they usually are between o.5 and 5cmm yet they have many characteristic shapes and sizes. Some bacteria are circular or oval shaped, they are known as cocci bacteria. Other bacteria are rod-shaped, they are known as bacilli bacteria, and some bacteria are spiral and coil-shaped and it is know as spirilla bacteria.
A male makes one thousand new sperm per second, that is two trillion over a lifetime and they all are one of a kind, very unique. A woman has all her eggs from birth. The process starts out as meiosis, this is where 30,000 genes are then there are forty six chromosomes. Twenty three comes from your mother and twenty three come from your father, they only come together in meiosis in pairs, but they are not the same. Chromosomes make an exact copy of themselves then they condense making an X shape, chromosomes get a partner then embrace. The chromosomes cling close together in big chunks, the cell then divides pulling the pair apart with twenty three chromosomes. The cell alone is incomplete, but holds many promises. Every cell holds di...
Prokaryotic cell: have no membrane covered organelles, they also have circular DNA and bacteria, Eukaryotic cell: have membrane covered organelles, they also have linear DNA and all other cells. Also the cell cycle is short in prokaryotic cells, roughly taking about 20-26 minutes to complete. And in eukaryotic cells, the cell cycle is long, it usually takes about 12-24 hours to complete. Below is a table of some of the differences between the cells:
The Cell, the fundamental structural unit of all living organisms. Some cells are complete organisms, such as the unicellular bacteria and protozoa, others, such as nerve, liver, and muscle cells, are specialized components of multicellular organisms. In another words, without cells we wouldn’t be able to live or function correctly. There are Animal Cells and Plant Cells. In Biology class the other day we studied the Animal Cell. We were split into groups of our own and we each picked a different animal cell slide to observe. My group chose the slide,'; Smeared Frog Blood ';.
The clusters inside the cells look like pairs of threads wound around each other in a helix. The tangles consist of a protein called tau. Tau binds to another protein called tubulin. Tubulin then forms structures called microtubules which run through cells, giving support and shape. Also the microtubules provide pathways for nutrients and other molecules to travel through.