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Chapter 1
1.1: You could shout; make a paper plane; ask the person next to you to pass a verbal message on, or pass a piece of paper on; you could force your way through the crowd. How does each of those methods relate to how cells carry messages, and what could possibly go wrong?
1.2: You started as an egg and sperm, but to make these cell signalling was needed. When you die (medically) your organs continue to use cell signalling, else organ transplants would not be possible.
1.3: Pheromones are volatile compounds released and sensed by other individuals. Those perceiving a pheromone may have their actions altered.
1.4: Discuss how proteins can be grouped into families and then how those families came about via evolution.
Chapter 2
2.1: You may wish to discuss mechanisms such as gene duplication or alternative splicing.
2.2: MISSING ANSWER
2.3: You may think about the speed of response or how molecules can be recycled. Besides ATP (being used for make cAMP) can you think of any other examples?
2.4: Think about the ‘lock and key’ mechanism of ligand-receptor binding.
Chapter 3
3.1: Consider how the activation levels of kinases may influence the result.
3.2: Think about what a prediction of a phosphorylation of a protein may mean physiologically. Also, think about what the potential phosphorylation may have on the protein’s function.
3.3: You may consider the ubiquitous nature of the substrate, specificity of kinases, reversal by phosphatases, capacity for amplification and translocation of the signal.
3.4: You will need to consider the action of lysosomes and the process of ubiquitylation.
Chapter 4
4.1: Think about the role of G proteins and how the toxin affects this, especially the ramifications for downstream signalling.
4.2: Because they are similar the catalysis for production is similar, but their downstream actions are quite different.
4.3: Investigate the action of the G protein Gt and how cGMP is involved. Much of the early work involved Lubert Stryer, so worth searching for his work or looking at his textbook (now ninth edition: ISBN-13:978-1319114657).
4.4: Look at G protein control, and also phosphorylation and dephosphorylation of the InsP4.
Chapter 5
5.1: Discuss how cells signal to each other during development.
5.2: Think how gene expression leads to the production of new proteins and new cellular functions.
5.3: Consider how organs are formed and why fingers are not webbed.
5.4: Think about plant development and also responses to plant stress (see Chapter 6).
Chapter 6
6.1: Think about how environments may change, how species may sense those changes and what species may do to mitigate against them.
6.2: Consider that plants are sessile, and that animals have an immune system. Also think about the similarities in the systems used.
6.3: Think about how they may be produced in times of stress but also their normal physiological roles.
6.4: Consider how viruses control gene expression and the translation of proteins.
Chapter 7
7.1: This may include germination, rates of growth, better responses to stress, better setting of seed or even post-harvest.
7.2: They may need to think about protein isoforms, crosstalk, divergence of signalling pathways or moonlighting roles of many proteins, but also discuss how problems may be invesitgated in the laboratory.
7.3: Here, the issues of consent need to be considered, and the use and disposal of any tissues under that consent. For animals, the welfare and justified used need to be considered. Discuss the principle of the 3Rs. i.e. Replacement, Reduction and Refinement.
Chapter 8
8.1: Many of these are growth factors. Use Google Scholar or PubMed for your searching.
8.2: Look at the different stages of insulin action: production, perception and action.
8.3: Use a database such as NCBI to find sequences and then run them through a multiple alignment tool such as Clustal Omega. Many bioinformatics tools can be found at www.expasy.org.
8.4: Both use RTKs, but downstream has significant differences, but also some similarities. For example, both can lead to alterations of nuclear activity.