hormonal communication

Question 1

State one way in which the nervous system decreases the heart rate. (1)

Answer 1

impulses along parasympathetic nerve /
impulses along vagus nerve /
nerve endings releasing acetycholine ;

Question 2

RNA polymerase and DNA polymerase are both enzymes. RNA polymerase is involved in the action of some control elements, whereas DNA polymerase is not.

Describe and explain the difference between the functions of these two enzymes. (4)

Answer 2

RNA polymerase:
makes mRNA ;
transcription ;
one strand (DNA) used / short section used /
one strand formed ;

DNA polymerase:
DNA replication ;
semi-conservative / both strands used /
whole length used / 2 strands formed ;
before , nuclear / cell , division ;

Question 3

The adrenaline molecule is not lipid-soluble, therefore it cannot pass directly through the cell surface membrane. In order to bring about changes inside the cell, adrenaline relies on a second messenger system.

Describe the events that occur after adrenaline reaches the cell surface membrane that then result in changes in metabolism inside the cell cytoplasm (4)

Answer 3

adrenaline binds to receptor ;
2 complementary / specific, fit / shape ;
3 G protein activated ;
4 adenyl(ate) cyclase activated ;
5 ATP converted to cAMP ;
6 cAMP activates, proteins / enzymes ;
7 by, altering 3D structure / phosphorylation ;