Cell Function 1

Question 1

Principles of homeostasis

Answer 1

stable functional state, when faced with environmental changes (internal = endogenous, external = exogenous)

Question 2

Feedback control systems require

Answer 2

sensor
integrator
effector

Question 3

When will a feedback loop close?

Answer 3

The loop closes when the sensor detects normal levels and reports to integrator which reports to effector

Costs energy to operate

Question 4

What is a negative feedback loop?

Answer 4

Most common

Biochemical entity acts on an earlier event to prevent more of itself from being formed

Wants to stay near set point

Question 5

Examples of negative feedback loops?

Answer 5

Control of arterial blood pressure

Control of blood glucose concentration

Interconversion of metabolites in a series of enzymatic reactions

Question 6

What is a positive feedback loop?

Answer 6

Rare

Accelerates/amplifys change

Promotes instability

Wants to deviate from set point

Question 7

Examples of positive feedback loops?

Answer 7

Ovulation

Transmission of an action potential in excitable cells