2.6-2.10 Quiz Review

Passive Transport

the net movement of molecules from high concentration to low concentration without the direct input of metabolic energy (ATP).

What role does passive transport play in the plasma membrane?

plays a role in the import of materials and the export of wastes

Active Transport

requires the direct input of energy (ATP) to move molecules from regions of low concentration to regions of high concentration; uses a channel protein

Endocytosis

requires energy to move large molecules into the cell; the cell takes in macromolecules and particulate matter by forming new vesicles derived from the plasma membrane

Exocytosis

requires energy to move large molecules out of the cell; internal vesicles fuse with the plasma membrane and secrete large macromolecules out of the cell

Rough ER→Ribosome→Golgi bodies→Vesicle→Exocytosis

Concentration gradient

the solute is going from a high concentration to a low concentration

Facilitated diffusion

a type of passive transport that requires a channel protein to make it easier for certain, charged/polar molecules to diffuse into the membrane

Phagocytosis (endocytosis)

endocytosis for food, become a food vacuole 

Pinocytosis (endocytosis)

endocytosis; cellular drinking, takes in water and solutes

Receptor-mediated (endocytosis)

endocytosis; receptors on the outside of the membrane identify substances to facilitate endocytosis 

Osmosis

passive transport; diffusion of water through a semi-permeable membrane;

water moves by this from areas of high-water potential (low solute concentration) to areas of low water potential (high solute concentration)

Hypertonic solution

high solute concentration in the solution; water leaves the cell causing the cell to shrink

Hypotonic solution 

low solute concentration in the solution; water enters the cell causing cell to expand

Isotonic solution

same solute concentration in the solution vs. in the cell; no net movement of water, equilibrium causing cell size to remain the same

Aquaporins

a type of channel protein in facilitated diffusion; large quantities of water pass through this

Channel proteins

a type of protein used in facilitated diffusion; have a hydrophilic (polar) region in the interior that allows the polar solute to pass right through

Carrier proteins 

a type of protein used in facilitated diffusion; bind to solute, changes shape to fit to the solute/molecules shape; this change in shape channels the solute into the membrane

Osmoregulation

maintains water balance and allows organisms to control their internal solute composition/water potential 

What way does water always flow in osmosis?

Hypotonic (high concentration)→Hypertonic (low concentration)

What do eukaryotic cells compartmentalize and how?

Membranes and membrane-bound organelles compartmentalize intracellular metabolic processes and specific enzymatic reactions

How do internal membranes facilitate cellular processes?

By minimizing competing interactions and by increasing surface areas where reactions can occur

Enzymatic reactions

receptors are activated by ATP and dephosphorylated by a phosphate

Metabolic processes

build lipids out of fatty acid chains

Transport of proteins

making materials that are needed outside of the cell

Key aspects of cellular compartmentalization:

1) Specialized functions

2) Controlled environments

3) Protection

4) Increased efficiency

5) Increased surface area

6) Contrast with prokaryotes 

Purpose of standard deviation 

to help researchers determine if their results are consistent or if there is a significant variability

LOW DEVIATION: indicated that the measurements are very similar and close to average

HIGH DEVIATION: indicates that there is a large amount of variability

Purpose of Z-Scores

Compares values, identifies outliers, and shows how unusual a data point is; a way to express a data point’s position relative to the mean.

SCORE OF 0: Data point is equal to the mean

POSITIVE SCORE: Value is above the mean

NEGATIVE SCORE: Value is below the mean