Lecture 1: Homeostasis and Cell Function Flashcards
An increase in the production of TSH releasing factor results in an increase of thyroid stimulating hormone, which results in a release of more thyroxine, which results in a decrease in the production of TSH releasing factor. Is this a negative or positive feedback loop? Explain.
Negative Feedback Loop. The result of initial step is an OPPOSITE effect. As the chain of events proceeds, the response eventually loops back to return TSH releasing factor levels to normal.
Which of the following would have to be a transmembrane protein?
A. receptor protein
B. protein binding to the cytoskeleton
C. channel protein
D. phosphorylase
C. channel protein
Which organelle(s) is/are associated with intracellular trafficking?
Endoplasmic Reticulum, Golgi
Which organelle(s) is/are associated with most ATP production?
Mitochondria
Which of the following organelles is directly associated with the synthesis of proteins for secretion?
A. Mitochondrion
B. Golgi Apparatus
C. Rough ER
D. Smooth ER
C. Rough ER
Homeostasis
Maintenance of nearly constant conditions in the internal environment; body’s environment stays relatively constant within limits
Which cation is most abundant in the extracellular fluid?
Na+
Which cation is most abundant in the intracellular fluid?
K+
Which anion is most abundant in the extracellular fluid?
Cl-
Negative Feedback Loop
change in some parameter causes a response that results in a return of that parameter to normal (baseline). The response REVERSES the direction of the initial condition
Positive Feedback Loop
change in some parameter causes a response that continues to change that parameter in the SAME direction as before. Input is intensified
Gain
degree of effectiveness with which a control system maintains constant conditions
Gain = correction/error
