Chapter 5: Endocrine system

Question 1

What are the two types of hormones and 3 their characteristics each?

Answer 1

Peptide: protein-based, water-soluble = cannot penetrate cell membrane so uses a glycoprotein, transported in blood plasma
Steroid: Cholesterol-based, water-insoluble = need a carrier protein in blood, diffuse through the membrane

Question 2

Give two examples of peptide hormones

Answer 2

Adrenaline and insulin

Question 3

Give two examples of steroid hormones

Answer 3

Oestrogen and testosterone

Question 4

Give one feature of the hormone receptors

Answer 4

Complementary to specific hormones - specific tertiary structure

Question 5

What is the process of a peptide hormone binding to a receptor cell?

Answer 5

Binds to glycoprotein - alters tertiary structure, which activates adenyl cyclase, which converts ATP to cAMP so it can activate other messengers in the cell

Question 6

What is the process of a steroid hormone signalling a target cell?

Answer 6

Binds to a carrier protein in the blood, diffuses through the plasma membrane, binds to an intracellular receptor, activated steroid receptor diffuses into the nucleus to bind to chromatin and increase transcription and protein synthesis

Question 7

Define a hormone

Answer 7

Chemical messenger transported in blood plasma

Question 8

Why are peptide hormones water soluble?

Answer 8

R groups in the amino acids are polar

Question 9

Why are steroid hormones water-insoluble?

Answer 9

Cholesterol based - lipids are water-insoluble

Question 10

When is adrenaline secreted?

Answer 10

When there is anactivation of the nerves on the adrenal glands when you’re stressed/excited

Question 11

Define glycogenolysis

Answer 11

Process of adrenaline preparing your body by making more glucose so muscles have more energy to respire

Question 12

What type of hormone is adrenaline?

Answer 12

peptide

Question 13

What does the adrenal medulla do?

Answer 13

Releases adrenaline and noradrenaline when the sympathetic nervous system is stimulated

Question 14

What are 5 physical effects of adrenaline and noradrenaline and why?

Answer 14

Relax smooth muscles in bronchioles - allows more air into lungs, Increases stroke volume and HR - more oxygen to muscles, vasoconstriction of arterioles to increase blood pressure, dilation of pupils to increase alertness

Question 15

What effect does adrenaline have on glucagon?

Answer 15

Stimulates secretion of glucagon to convert glycogen to glucose - supply muscles with energy

Question 16

What is gluconeogenesis?

Answer 16

When cortisol controls how the body converts fats, proteins and carbohydrates to energy - new glucose