CAS BI 105 Lecture Notes - Lecture 6: Apoptosis, Cyclic Adenosine Monophosphate, Mitosis
14 Dec 2017
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Document Summary
There are 50 trillion cells in the human body and all cells require communication (signaling) to survive. From inside: cell to cell communication (cells receiving a message are targets hormone that controls cell reproduction, electrical wave down a neuron causes muscle contraction. From outside: uv rays cause increase in melanin production, activation of vitamin d. cells need to be able to respond to environmental changes. Other uses for signaling is communication between organisms who cannot communicate verbally (yeast, bacteria, insects). Very local: two cells are connected by gap junctions. Long distance: secreted molecules that diffuse or are carried (bloodstream) throughout the organism. Autocrine signaling: a cell secretes a molecule that effects itself. Paracrine signaling: a cell secretes a molecule that effects neighboring cells. Endocrine signaling: a molecule is secreted into the bloodstream. Cells that are receiving the signal are targets and a receptor is required. The secreted molecule is called the ligand for the receptor.
