Answer the following questions about Molecular Celullar: 1. Mention the most imp
ID: 273537 • Letter: A
Question
Answer the following questions about Molecular Celullar:
1. Mention the most important proteins that are involved in the translation of cellular signals. Specify which ones are involved in the reception of the message, its translation, its amplification and the activation chains that carry out these messages within the cell. Specific examples of how these proteins work and the messages they receive, transmit and match.
2. The forms communicate that they resemble the forms of human communication. Decide which of the following forms of communication are analogous to the autocrine, paracrine, endocrine and synaptic systems?
a. telephone conversation
b. talk to people at a family party
c. a radio message
d. talk to yourself
Explain your answers and give an example of each of these forms of cell communication.
3. It is said that depressed people have low levels of serotonin in their brain. According to what was learned in the class, how do you understand this neurotransmitter at the molecular level? Explain examples of other functions controlled by neurotransmitters in an organism.
4. Name the types of transport of proteins that exist in the cell and an example of a transported protein for each of these types of transport. Explain where the protein originates, where it goes and what is its function? What mechanisms ensure that this is not degraded through this route?
5. Mention the most important characteristics of biological membranes and how those characteristics allow you to maintain a living organism.
Explanation / Answer
Q5) Biological membranes consist of a double sheet (known as a bilayer) of lipid molecules. This structure is generally referred to as the phospholipid bilayer. In addition to the various types of lipids that occur in biological membranes, membrane proteins and sugars are also key components of the structure. Membrane proteins play a vital role in biological membranes, as they help to maintain the structural integrity, organization and flow of material through membranes. Sugars are found on one side of the bilayer only, and are attached by covalent bonds to some lipids and proteins.
Three types of lipid are found in biological membranes, namely phospholipids, glycolipids and sterols. Phospholipids consist of two fatty acid chains linked to glycerol and a phosphate group. Phospholipids containing glycerol are referred to as glycerophospholipids. An example of a glycerophospholipid that is commonly found in biological membranes is phosphatidylcholine, which has a choline molecule attached to the phosphate group. Serine and ethanolamine can replace the choline in this position, and these lipids are called phosphatidylserine and phosphatidylethanolamine respectively. Phospholipids can also be sphingophospholipids (based on sphingosine), such as sphingomyelin. Glycolipids can contain either glycerol or sphingosine, and always have a sugar such as glucose in place of the phosphate head found in phospholipids. Sterols are absent from most bacterial membranes, but are an important component of animal (typically cholesterol) and plant (mainly stigmasterol) membranes. Cholesterol has a quite different structure to that of the phospholipids and glycolipids. It consists of a hydroxyl group (which is the hydrophilic ‘head’ region), a four-ring steroid structure and a short hydrocarbon side chain