ZOOLOGY 470 Study Guide - Growth Factor, Vitamin A, Inositol Trisphosphate
Document Summary
Hormones: in an early embryo there is no blood stream so hormones are not useful in transmitting signals. Local mediators: act at short range and are very specific. Growth factor signals secreted proteins with small range activity (which is limited by how far they can diffuse) responding cells need receptors and different cells respond differently. Ways to deliver a message: growth factors by diffusion, contact, signals in ecm. Other parts of cells respond to the evaluation of these ions. Phospholipase cleaves phosphatitol inositol biphosphate (pip3: diacylglcerol (dag) goes into cell membrane. Ip3 goes to er where ca is stored. Ip3 binds to receptor on er membrane opening a channel letting the ca ions out into the cytoplasm creating a cellular response to the elevated levels. Signal transduction: series if enzymatic reactions that change proteins (that will move into nucleus to affect genes) Proteins are also know as transcription factors. Fibroblast growth factors (fgf) epidermal growth factors (egf)
