Bio OAT 1 Flashcards
Arrange the terms in order of organisational hierachy: organ, cell, tissue, system, organism
Organism -> system -> organ -> tissue -> cell
Definition of organ
A collection of tissues that structurally form a functional unit specialised to perform a particular function
Definition of organsim
An individual animal, plant, or single-celled life form
What is homeostasis?
The maintenance of a condition of the internal environment, within narrow limits.
What is meant by internal environment when referring to homeostasis?
Refers to the fluid surrounding the cells which remains constant due to homeostasis.
____ acts in the ____ direction to the stimulus.
Negative feedback, opposite
Why is glucose important for cells?
Glucose is broken down to form ATP in cellular respiration, provides an energy source for all cellular reactions
What problem would occur if glucose was stored in the body as glucose?
Because glucose is soluble in water, fluid from outside the cells would enter via osmosis, causing them to burst.
Name the polymer and location of stored glucose
Glycogen is stored in the liver and skeletal muscle
Insulin is produced by…
Glucagon is produced by…
Beta cells
Alpha cells
The first key response to blood glucose levels is…
Insulin release to allow absorption of glucose into cells and to be converted to glycogen
The second key response to blood glucose levels is…
Glucagon production is decreased so glycogen is not converted to glucose, increasing blood sugar.
Define diabetes
A failure in the regulation of glucose uptake by cells.
Type 1 = autoimmune disorder, beta cells destroyed in islets of Langerhan
Type 2 = body becomes resistant to insulin
Why might fatigue be a symptom of diabetes?
As insulin producing beta cells are attacked in type 1 diabetes, insulin production decreases.
Positive feedback
Increases the stimulus
