A signal reaches a cell mostly in the form of a signalling molecule binding to a receptor on the cell surface. This binding activates a chain of events that amplifies the signal and transfers it inside the cell. Protein kinases phosphorylate proteins and cause their activation or deactivation, or in general modify their activity. When a signalling molecule binds to a receptor, a cascade is activated and the second messengers, such as cAMP, are synthesized. cAMP molecules activate the protein kinases, which phosphorylate specific proteins and activate them.
Answer:
A
Explanation:
It allows the cell to control what materials enter and leave.
The correct answer is that "for most clients, surgery is recommended only if non-surgical treatments have been unsuccessful." This is because of the guidelines involving medicine and surgery as well as guidelines involving the treatment of colitis. The question should have specified what type of colitis is the patient having, whether infectious or autoimmune. In infectious colitis, then surgery almost has no role and medical treatment with antibiotics as well as supportive therapy and fluid replacement are the only ones needed. In autoimmune colitis such as Crohn's disease or ulcerative colitis, while immunosuppressor drugs may have a role, surgery may be the mainstay of treatment especially those who are at risk of malignant degeneration.
Consumers/producers: A surplus of consumers and a reduced amount of producers cause an ecosystem to collapse. Their are more mouths to feed then there is food
Answer:
The correct answer is option E.
Explanation:
The deep-colored, water-soluble proteins, which are mainly found in Rhodophyta and cyanobacteria are known as phycobiliproteins. They captivate the light energy and then pass it to the chlorophyll at the time of photosynthesis.
They are comprised of proteins and are covalently attached through cysteine amino acid chromophores known as phycobilins. Thus, the correct answer is option E.
