Rationale The cell membrane, also called the plasma membrane is found in all cells and separates the extracellular side of the cell from the cytosolic side (Cell membrane (plasma membrane), 2023). The purpose of the cell membrane is to communicate with the cell’s external environment, to contain the cell’s contents and to control the transport of molecules in and out of the cell. Diffusion is the passive movement of molecules from an area of high to low concentration.
Organelles as organism is from The Lives of a cell authored by Lewis Thomas. Thomas uses a unique writing style that is very recognizable and different from the others. This helps us to appreciate our diversity as human beings demonstrated by our abilities to write differently. As a reader one is able to form an image of who Thomas is by how he expresses his feelings and attitudes. When this text was written a lot of people, mostly scientists, thought and had knowledge of different things than they do now.
Elijah Brycth B. Jarlos IX-Argon 1. Multicellularity is a condition of an organism to have multicellular cells. An example of a organism who has multicellular cells are plants, animals, and humans. The main reason of why scientists have a hard time finding a good set of existing organisms to compare. Is neither the first set of organisms which is being compared is dying as fast as the second specimen is being examined or they just can’t find the right species.
Biology 15 Lab # 3 Professor Passerini September 23, 2015 Scot Albert Lab #3 Questions 1, 2a, 3, 4, 5, 6a, 7, and 8 Table 3.1 - all columns except the last one. -------------------------------------------------- 1- a-Upside down and backwards b- If you move it right, the image moves left If you move it left, the image moves right c -
Biology, the study of life and living organisms, is complex and encompasses a multitude of theories and ideas. In AP Biology, the first unit covered was evolution. Chapters 29, 31, 39, 40, 41, 42, and 43 in the textbook, Campbell’s Biology in Focus, not only discusses the four main ideas of biology: evolution, energy, information, and systems, but it also gives examples of each in order to help guide the reader’s understanding of the concepts. The first big idea of AP Biology is: “the process of evolution drives the diversity and unity of life.” Chapter 39 in the textbook encompasses this main idea through discussing natural selection and genetic diversity.
The head of the phospholipid faces towards the water inside/outside of the cell. The middle layer of the membrane consists of the hydrophobic region. They form the lipid tails and they hate water. Since lipids and water does not mix well together, the middle of the phospholipid bilayer does not allow water to go inside. 2.
Throughout Chapter 9, many different concepts related to genetic material are introduced such as many different experiments from scientists such as Griffith and Avery, the role of DNA, the structure of DNA, and the replication of DNA. In section 1, you are introduced to Frederick Griffith’s experiment testing for a vaccine against the S pneumoniae which resulted in his discovery of transformation. According the the textbook, the definition of transformation is: a change in phenotype caused when bacterial cells take up foreign genetic material. You are also introduced to Oswald Avery’s experiments that demonstrated that DNA is the material responsible for transformation. Lastly, in section 1 you are introduced to Alfred Hershey and Martha Chase’s
1.Why does it make sense that all composition of the cell membrane is largely a lipid? The cystol and all parts of the cell are made up of very polar; water-soluble molecules, which are hydrophilic “water loving”. The environment outside the cell is also very polar and water-soluble. In order to have an appropriate barrier between the inside of the cell and the outside, The membrane of the cell needs to be made of highly non-polar, organic material like lipids.
• When in water the phospholipid (A) is arranged in that particular manner because there are two layers of phospholipids aligned straight. The phosphate head’s polar and hydrophilic nature tends the head to face the outside, attracting towards the water while the tails having a non-polar hydrophobic nature are faced inside repelling the liquid and moving away from it. • The glycoproteins (C) are proteins embedded into the phospholipid bilayer by electrostatic and hydrophilic forces similar to that of the phosphate head with carbohydrate chains attached to the outer surface. The hydrophilic nature of the glycoprotein tends it to move towards the liquid (water) and so, it is arranged similar to the phospholipid. (c)
The cell membrane regulates the deoxyribonucleic acid, enzymes, and it builds a pathways for any reaction such as metabolic. When waste products are present the cell membrane gets rid of it and the cell membrane allows important things inside . A great example of what the cell membrane allows in or out is water and oxygen. Specific molecules are only made to enter the cell which is also called semipermeable. Molecules can be passed by active transport or either passive transport.
Figure 12.3 Eukaryotic chromosomes shows chromosomes that are stained purple in order to make visible the chromosomes of an African blood lily. The thin red lines in the cytoplasm are the cytoskeleton in a cell that is getting ready to divide. Chromosomes carry the genetic information for each organism. The chromosomes go through changes when cells divide in order to ensure the genetic information is passed to every cell in an organism.
Assignment unit 3 1. Unlike prokaryotic cells, eukaryotic cells have: 1) a membrane-bound nucleus; 2) numerous membrane-bound organelles such as the endoplasmic reticulum, Golgi apparatus, chloroplasts, mitochondria, and others; and 3) several, rod-shaped chromosomes. Because a eukaryotic cell’s nucleus is surrounded by a membrane, it is often said to have a “true nucleus.” The word “organelle” means “little organ,” and, as already mentioned, organelles have specialized cellular functions, just as the organs of your body have specialized functions. At this point, it should be clear to you that eukaryotic cells have a more complex structure than prokaryotic cells. Organelles allow different functions to be compartmentalized in different areas
The cell membrane is a thin semi-permeable membrane that surrounds the cytoplasm of a cell, enclosing its contents. The cell membrane is very selective on what comes to into the cell and this process is called the selective preamble membrane. The cell membrane structure is shaped as a phosphate head at the very outer surface, and two fatty acid tails hanging from it. The membrane is double, so at the tip of the fatty acid tails, there are two more fatty acid tails attached to another phosphate head. The main reason that the cell membrane has a structure like this is so it can control the amount of water the cell is receiving and releasing.
eukaryotic it is any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes are located. Eukaryotic cells also contain organelles, including mitochondria , a Golgi apparatus , an endoplasmic reticulum and lysosomes . example of eukaryotic cell The protists Protists are one-celled eukaryotes.
Prokaryotic and eukaryotic cells must uphold an internal environment different than the outside in order to survive. The plasma membrane helps the cell achieve this. It is describe as a thin, flexible, oily sheet that puts a boundary between the cell and its environment. An important feature is that the membrane regulates movement of material in and out of the cell. While some cells can come and go as they want; others can only pass under certain conditions.
