Prokaryotic Cell Biology

1728 Words 7 Pages
The next topic a student should be schooled in is cells and cellular biology. While cells are the building blocks of all living organism, scientists have confirmed that there are actually different types of cells depending on the organism. The two main classes of organisms are the prokaryotes and the eukaryotes. The prokaryotic is the simpler of the two and are the one-celled organisms such as bacteria and archaea. The interior of a prokaryotic cell consists of a main nucleoid, which contains the DNA, the ribosomes, which synthesize proteins, and the cytoplasm, which is a liquid cytosol that suspends the organelles. The cell is surrounded by a plasma membrane, which facilitates what enters or leaves the cell, a cell wall, which gives rigidity …show more content…
Photosynthesis takes in sunlight, carbon dioxide, and water to produce oxygen and glucose through light reactions and the Calvin cycle. This process starts in the chloroplasts of the plant cells. The chlorophyll in the chloroplasts absorb solar energy and converts this to ATP and NADPH. This is achieved when the light energy drives electrons from water to NADP+ to create the NADPH. When the water molecule is split, oxygen is produced as a by-product. The next step in this process is called the Calvin cycle. The Calvin cycle takes in the ATP and the NADPH from the light reactions and uses this energy to break down carbon dioxide and convert it into …show more content…
Cells reproduce by replicating themselves. There are two types of reproduction, meiosis and mitosis. Meiosis is what most of us think about when considering reproduction, it is the process of sexual reproduction. There are several stages of meiosis, all with the cumulative goal of creating haploid gametes from the diploid cells. In laymen terms, the genetic material from the egg and sperm are combined to create daughter cells with a complete complement of chromosomes. The first stage of meiosis is called Interphase. This is when the chromosomes are duplicated in preparation for the division. The next 4 stages are referred to as meiosis I. Prophase I is when the homologous chromosomes pair up and exchange segments. Metaphase I is when the pairs of chromosomes line up along the spindle. Anaphase I is when the pairs of chromosomes split up. The sister chromatids remain attached. Telophase I is when the chromosomes arrive at the poles of the cell. At this point cytokinesis occurs, which is the division of the cytoplasm of the cell, to form two daughter cells. The daughter cells are haploid cells but the still have duplicated chromosomes. The next 4 stages, referred to as Meiosis II, are the same as Meiosis I, except that the separation is of the sister chromatids instead of the homologous chromosomes. Both daughter cells from meiosis I go through meiosis II so the final result is 4

Related Documents