Introduction to signalling molecules

Question 1

thing in common with all signalling molecules is that

Answer 1

they bind to specific/complementary receports on their target cells

Question 2

signalling molecules are aka

Answer 2

ligands

Question 3

describe types of forms of signals (physical etc)

Answer 3

chemical (Eg. signalling molecules), mechanical (touch/pressure like pressure receptors in joints), electromagnetic (like photoreceptors in the eyes)

Question 4

signalling molecules have varying chemical structurs, being made of

Answer 4

aa’s pp’s peptides, proteins

Question 5

also have

Answer 5

varying sizes, water affinities, functions (neurotransmitters, cytokines)

Question 6

signalling molecules can be grouped

Answer 6

in how far they ahve to go to exert effect on target cells.

Question 7

define: endocrine signalling

Answer 7

: secreted directly into circulatory system and distributed widely throughout the body (hormones)

Question 8

define: paracrine singalling

Answer 8

signals move by diffusion through interstitial fluid to nearby cells

Question 9

define: autocrine signalling

Answer 9

secreted from cell that receives the signal (eg. T cells)

Question 10

define: contact dependent signalling

Answer 10

: signals move from the cytosol of one cell to that of another due to structural features

Question 11

strcutral features enabling contact dependent signalling?

Answer 11

gap junctions (in animal cells, protein lined pores in the plasma membrane, enabling small molecules and electrical signals to pass) and plasmodesmata (equivalent in plants)