Organisms Respond to their Internal and External Environments: Homeostasis - Control of Blood Glucose Concentration, Adrenaline Flashcards
1
Q
Does adrenaline lower or raise blood glucose concentration?
A
- Adrenaline raises blood glucose concentration
2
Q
What organs secrete adrenaline?
A
- Adrenal glands
3
Q
Where are adrenal glands located?
A
- Above the kidneys
4
Q
What is the name of the model adrenaline and glucagon use?
A
- Second messenger model
5
Q
What are the main actions of adrenaline?
A
- Attaching to receptors on the surfaces of target cells (e.g liver cells)
- Activating enzymes/chemicals (adenylate cyclase, cAMP, protein kinase A) involved in glycogenolysis
6
Q
What are the target organs/cells of adrenaline?
A
- Liver cells
- Heart
- Many more
7
Q
Explain what happens when adrenaline attaches to the receptors of liver cells
A
- Adrenaline binds to receptors on surface of liver cells
- Activates enzyme adenylate cyclase
- Adenylate cyclase converts ATP into cyclic AMP (cAMP), a second messenger
- cAMP activates enzyme protein kinase A
- Protein kinase A activates a cascade leading to glycogenolysis
8
Q
What is the second messenger model?
A
- The binding of the hormone to cell receptors to activate an enzyme inside the cell membrane
- This produces a second messenger chemical
- The second messenger activates other enzymes to bring about a response
9
Q
What are the chemicals involved in the second messenger model of adrenaline and glucagon in liver cells?
A
- Adenylate cyclase
- Cyclic AMP (CAMP)
- Protein kinase A
10
Q
Define the term cascade
A
- A chain of reactions
11
Q
What does adenylate cyclase do?
A
- Enzyme that converts ATP into cAMP
12
Q
What does cAMP do?
A
- Second messenger that activates protein kinase A
13
Q
What does protein kinase A do?
A
- Enzyme that activates a cascade involved in glycogenolysis
14
Q
What processes does adrenaline activate and inhibit?
A
• Activates
- Glycogenolysis
- Glucagon secretion
• Inhibits
- Glycogenesis
- Insulin secretion
