Cell Bio 3

Question 1

form follows ?

Answer 1

function

Question 2

If precursor and product molecules are co-existing in an aqueous environment, how is the cell able to separate into compartments?

Answer 2

Compartments allow systems to establish local environments, control reactant interactions and resist the randomization of entropy.

Question 3

entropy

Answer 3

entropy is defined as a measure of randomness or disorder of a system

Question 4

Polar heads associate with aqueous (polar)

Answer 4

solvent

Question 5

aliphatic tail associates with hydrophobic (non-polar)

Answer 5

solute

Question 6

Able to build a hydrophobic wall or membrane with aliphatic molecules, hydrophilic head group and hydrophobic tail. What is the function?

Answer 6

Function to keep unwanted molecules out of the cell, and wanted molecules inside of the cell-selective permeability.

Question 7

Short distance (signaling cell is adjacent to the target cell) has which hormone?

Answer 7

Paracrine - “local hormones”

Neurotransmission is a specialized form of paracrine signaling

Contact dependent - signal molecule and receptor molecule both fixed to cell membranes so they require cell-cell contact

Question 8

Long distance signals (signaling cell is distant from the target cell)

Answer 8

Endocrine signal: circulating, diffusible chemical = hormone

Neuronal-electrical: signals carried over nerves, sometimes great distances, via the cell/axon

Question 9

One signal molecule can evoke different responses in different cells, one cell type can receive multiple signals, exhibit qualitatively different responses, integrate multiple signals to exhibit quantitatively different responses
Integrated response to signals provides? flexibility and control

Answer 9

Integrated response to signals provides flexibility and control

Question 10

Receptor Location & Membrane Permeability - either in cell, or in other cells, near or far depending on the signal. Membrane has selective permeability which is aided by

Answer 10

aided by channels and pores when transport across membranes is necessary.

Question 11

Ion-channel linked receptors
Voltage-gated ion channel – e.g. H+, Na+, K+, Ca2+, Cl-

Answer 11

Receptors linked to ion channels respond to specific activating signals by allowing (inorganic) ions to move across the plasmalemma which changes the electrical potential across the cell membrane.

Why?
Because cell membrane electrical potentials are dependent on differences in ion compositions on each side of – and thus across the membrane (lipids, ion channels, ion pumps)

Question 12

Ligand-linked receptor

Answer 12

Acetylcholine receptor – AchR

Question 13

G-protein-linked receptors

Answer 13

C-AMP and phosphatidylinositol pathways

Question 14

Enzyme-linked Receptors

Answer 14

Epidermal growth factor – Tyr Kinase

Toll-like receptor (TLR) – Tyr Kinase

Guanylate cyclase activity