cell signalling intro

Question 1

what is the purpose of signal transduction

Answer 1

it converts biotic/abiotic information into a form inside the cell that can be interpreted & acted upon

Question 2

examples of abiotic information

Answer 2

pH, salinity, pressure, light

Question 3

examples of biotic information

Answer 3

hormones, growth factors, neurotransmitters

Question 4

what are the steps in the general signal transduction cascade

Answer 4

extracellular signal molecule -> receptor protein -> intracellular signalling proteins -> target proteins

Question 5

difference between cell-surface receptors and intracellular receptors

Answer 5

cell-surface receptors bind hydrophilic ligands on the cell surface and convert extracellular signals into intracellular signals.

intracellular receptors exist inside the cytoplasm and bind hydrophobic ligands that cross the membrane via carrier molecules

Question 6

what are the 4 categories of chemical signalling

Answer 6

endocrine (hormones, long distance), paracrine (diffusion, short distance), autocrine (self signalling), contact dependent (to neighbour cells via gap junctions)