Title: .Biology Semester 2 / Hormones
Tags: homeostasis definition

Q: Define homeostasis
A: The maintenance of a constant internal environment within normal set limits despite external changes

Q: Positive feedback is usually [...] and does not lead to [...]
A: harmful; homeostasis

Q: Controlling blood glucose concentration is a [...] which is an example of a [...] feedback loop
A: homeostatic mechanism; negative

Q: Why is controlling blood glucose concentration important?
A: 1. Main respiratory substrate for all cells
2. ONLY respiratory substrate in the brain

Q: Describe the impact of blood glucose levels being too high
A: Lowers the water potential of blood
Water leaves cells (from area of higher concentration to area of lower concentration)
Cells dehydrate

Q: Describe the impact of blood glucose levels being too low
A: Deprive cells of respiratory substrate/energy
Cell death

Q: Normal blood glucose concentration = [...]
A: 80 - 120mg per 100cm³

Original: 1. [[oc1::Directly from diet]]
2. [[oc2::Glycogenolysis]] - [[oc3::the breakdown of glycogen stores in muscles and liver]]
3. [[oc4::Gluconeogenesis]] - [[oc5::using glycerol and amino acids to produce glucose]]
Title: 3 sources of glucose in the blood
Q: 1. [...]
2. Glycogenolysis - ...
3. ... - ...
A: Directly from diet
Q: 1. Directly from diet
2. [...] - the breakdown of glycogen stores in muscles and liver
3. ... - ...
A: Glycogenolysis
Q: 1. ...
2. Glycogenolysis - [...]
3. Gluconeogenesis - ...
A: the breakdown of glycogen stores in muscles and liver
Q: 1. ...
2. ... - the breakdown of glycogen stores in muscles and liver
3. [...] - using glycerol and amino acids to produce glucose
A: Gluconeogenesis
Q: 1. ...
2. ... - ...
3. Gluconeogenesis - [...]
A: using glycerol and amino acids to produce glucose
1. Directly from diet
2. Glycogenolysis - the breakdown of glycogen stores in muscles and liver
3. Gluconeogenesis - using glycerol and amino acids to produce glucose
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Q: Define endocrine gland
A: An endocrine gland is a ductless gland that secretes hormones directly into the blood

Q: Define glycogenolysis
A: The breakdown of glycogen stores in the muscle and liver

Q: Define gluconeogenesis
A: The production of glucose from glycerol and amino acids

Q: Define hormone
A: A hormone is a regulating chemical, produced by an endocrine gland,
and is carried in the blood to the target cells, tissues or organs, on which it acts

The Islets of Langerhans are a group of cells located in the pancreas, functioning as an endocrine gland that secrete hormones to control blood glucose concentrations via a negative feedback mechanism

Original: 1. [[oc1::Small molecules]]
2. [[oc2::Effective in small concentrations]]
3. [[oc3::Transported in the blood]]
4. [[oc4::Produced by endocrine glands]]
5. [[oc5::Short lifespan]]
6. [[oc6::Often proteinaceous (insulin and glucagon) or steroidal]]
Title: Characteristics of Hormones
Q: 1. [...]
2. Effective in small concentrations
3. ...
4. ...
5. ...
6. ...
A: Small molecules
Q: 1. Small molecules
2. [...]
3. Transported in the blood
4. ...
5. ...
6. ...
A: Effective in small concentrations
Q: 1. ...
2. Effective in small concentrations
3. [...]
4. Produced by endocrine glands
5. ...
6. ...
A: Transported in the blood
Q: 1. ...
2. ...
3. Transported in the blood
4. [...]
5. Short lifespan
6. ...
A: Produced by endocrine glands
Q: 1. ...
2. ...
3. ...
4. Produced by endocrine glands
5. [...]
6. Often proteinaceous (insulin and glucagon) or steroidal
A: Short lifespan
Q: 1. ...
2. ...
3. ...
4. ...
5. Short lifespan
6. [...]
A: Often proteinaceous (insulin and glucagon) or steroidal
1. Small molecules
2. Effective in small concentrations
3. Transported in the blood
4. Produced by endocrine glands
5. Short lifespan
6. Often proteinaceous (insulin and glucagon) or steroidal
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Q: [...] cells secrete [...] which [...] blood glucose concentration
A: Alpha; glucagon; increases

Q: [...] cells secrete [...] which [...] the blood glucose concentration
A: Beta; insulin; lowers

When blood glucose concentrations are high, alpha cells stop secreting glucagon and beta cells start secreting insulin

Original: 1. [[oc1::Increasing the absorbtion of glucose from the blood]]
2. [[oc2::Increasing the rate of respiration of glucose]]
3. [[oc3::Increasing the rate of glycogenesis in liver and muscles]]
4. [[oc4::Increasing rate of glucose conversion to fat]]
Title: 4 ways insulin lowers blood glucose
Q: 1. [...]
2. Increasing the rate of respiration of glucose
3. ...
4. ...
A: Increasing the absorbtion of glucose from the blood
Q: 1. Increasing the absorbtion of glucose from the blood
2. [...]
3. Increasing the rate of glycogenesis in liver and muscles
4. ...
A: Increasing the rate of respiration of glucose
Q: 1. ...
2. Increasing the rate of respiration of glucose
3. [...]
4. Increasing rate of glucose conversion to fat
A: Increasing the rate of glycogenesis in liver and muscles
Q: 1. ...
2. ...
3. Increasing the rate of glycogenesis in liver and muscles
4. [...]
A: Increasing rate of glucose conversion to fat
1. Increasing the absorbtion of glucose from the blood
2. Increasing the rate of respiration of glucose
3. Increasing the rate of glycogenesis in liver and muscles
4. Increasing rate of glucose conversion to fat
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When blood glucose levels are low, beta cells stop secreting insulin and alpha cells start secreting glucagon

Original: 1. [[oc1::Increasing rate of glygogenolysis- the breakdown of glycogen into glucose]]
2. [[oc2::Increases the rate of respiration of fatty acids instead of glucose]]
3. [[oc3::Increases gluconeogenesis, production of glucose from non-carbohydrate sources: amino acids, glycerol]]
Title: How does glucagon increase blood glucose concentrations?
Q: 1. [...]
2. Increases the rate of respiration of fatty acids instead of glucose
3. ...
A: Increasing rate of glygogenolysis- the breakdown of glycogen into glucose
Q: 1. Increasing rate of glygogenolysis- the breakdown of glycogen into glucose
2. [...]
3. Increases gluconeogenesis, production of glucose from non-carbohydrate sources: amino acids, glycerol
A: Increases the rate of respiration of fatty acids instead of glucose
Q: 1. ...
2. Increases the rate of respiration of fatty acids instead of glucose
3. [...]
A: Increases gluconeogenesis, production of glucose from non-carbohydrate sources: amino acids, glycerol
Q: 1. [...]
2. [...]
3. [...]
A: Increasing rate of glygogenolysis- the breakdown of glycogen into glucose; Increases the rate of respiration of fatty acids instead of glucose; Increases gluconeogenesis, production of glucose from non-carbohydrate sources: amino acids, glycerol
Other fields (not shown on cards):
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Q: [...] only effects [...] because [...]
A: Glucagon; liver cells; they are the only cells to have receptors complimentary with glucagon on their cell surface membrane

Q: Glucagon and insulin act [...]
A: antagonistically

Q: Exocrine glands have a [...]
A: duct

Q: Pancreas's [...] cells secrete digestive enzyme into pancreatic duct. Also produces [...] to neutralise stomach acid
A: Exocrine; sodium hydrogen carbonate

Q: Hormones must be small in order to pass through [...]
A: capillary pores

Q: Steroid hormones include [...] and [...] which are lipid based
A: testosterone; estrogen

Q: Wobbly cell membrane - [...]
A: highly invaginated

Q: Blood glucose concentration rises
[...] (receptors) detect change
Antagonistic response:
[...]
Which causes:
[...]
Result: blood glucose concentration descreases
A: Alpha and beta cells; Alpha cells stop secreting glucagon
Beta cells start secreting insulin; Increased respiration, increase glucose uptake, increase glycogenesis, convert to lipid

Blood glucose drops below set reference values
Alpha and beta cells detect change
Antagonistic response
Alpha cells secrete glucagon
Beta cells stop secreting insulin
Cellular changes:
Respire fatty acids instead of glucose, glycogenolysis, gluconeogenesis
Increase of blood glucose

Q: Explain the terms tissue and organ with reference to the structure of the pancreas
A: • A tissue is a collection of cells, together with any cellular secretions, that are specialised to perform one or more particular functions
• alpha cells secrete glucagon and beta cells secrete insulin regulate blood glucose concentration, form islets of Langerhans tissue
• An Organ is a collection a tissues that perform a specific function(s)
• Endocrine tissues and exocrine tissues (that secrete digestive enzymes and NaHCO₃ into the pancreatic duct) form pancreas

Q: Where does gluconeogenesis andglycogenolysis take place?
A: Liver cells

Q: In type 2 diabetes, patients have cells which do not repond to insulin. Explain how this reduces ability to control blood glucose concentration
A: Fewer/abnormal insulin receptors on cell surface membrane
Fewer active glucose transport proteins
Less glucose can enter cells
Less glucose can be converted to glycogen
So blood glucose not lowered when high

Q: Too much glucose for [...] to reabsorb, means all transporters are [...]
A: proximal convoluted tubule; saturated