1. Visual Vocab Unit 3

• ByAndrew Shaw AP Bio II 5 th

2. Amphipathic

Pertains to a molecule containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure.

shows the amphipathic nature of the bound glycopeptides. 3. Aquaporins

Aquaporins are proteins embedded in the cell membrane that regulate the flow of water

The 3D structure of aquaporin highlighting the 'hourglass'-shaped water channel that cuts through the center of the protein. 4. Concentration Gradient

a gradual change in the concentration of solutes in a solution as a function of distance through a solution.

The concentration of BCD protein appears to direct the A-P cell fates, and is responsible for the cascade leading to the differentiation of head, thorax and abdomen segments. Which is the concentration gradient. 5. Contractile Vacuole

a specialized vacuole of eukaryote cells, especially protozoa, that fills with water from the cytoplasm and then discharges this externally by the opening of a permanent narrow neck.

6. Cotransport

The linked, simultaneous transport one substance across a membrane, coupled with the simultaneous transport of another substance across the same membrane in the same direction.

A well-studied example of symport is the cotransport of glucose and sodium into the small intestinal absorptive epithelial cell. 7. Diffusion

The net movement of a substance from a region where it has a higher concentration to a region where it has a lower concentration, due to random molecular motion

Yellow food coloring diffusing through water 8. Electrochemical Gradient

The diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential.

The P-type plasma membrane (PM) H+-ATPase is found in fungi and plants and is the physiological equivalent of the animal Na+,K+-ATPase by being responsible for generating the essential electrochemical gradient across the plasma membrane. 9. Hypertonic

higher solute concentration compared with another

In hypertonic environments the cell membrane of plant cells pulls away from th wall in plasmolysis

10. Hypotonic

a solution with a comparatively lower concentration of solutes compared to another

For a plant in a hypotonic environment, the inflow of water results in turgor pressure against the cell wall, and the cells become turgid, contributing to rigidity and support. 11. Integral Protein

An integral membrane protein is a protein molecule that is permanently attached to the biological membrane.

Lactose permease (LacY) is an integral membrane protein 12. Isotonic

a solution that has the same tonicity as some other solution with which it is compared.

In isotonic environments plants become flaccid 13. Ligands

a signal triggering molecule, binding to a site on a target protein.

Myoglobin (blue) with its ligand heme (orange) bound. 14. Membrane Potential

the difference in voltage (also called electrical potential) between the interior and exterior of a cell (Vinterior Vexterior).

15. Osmoregulation

The process of regulating water potential in order to keep fluid and electrolyte balance within a cell or organism relative to the surrounding.

Marine Reptiles maintain osmotic homeostasis by excreting a hyperosmotic, sodium chloride-rich fluid from their bodies in the surrounding waters. 16. Osmosis

Tendency of water to flow from a hypotonic solution (low concentration of dissolved substances) to hypertonic solution (higher concentration of dissolved substances) across a semipermeable membrane

This is a shot from a three dimensional computer simulation of the process of osmosis. The blue mesh is impermeable to the larger balls, whereas all of the balls are (in the animated version) bouncing about according to the rules of physical simulation of the kinetics of an ideal gas. 17. Passive Transport

moving biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve chemical energy

In cells the membrane through which the molecules pass is the cell membrane 18. Peripheral Protein

proteins that adhere only temporarily to the biological membrane with which they are associated

Examples of peripheral membrane proteins are proteins involved in electron transport chains, such as cytochrome c, cupredoxins, high potential iron protein, adrenodoxin reductase, some flavoproteins, and others. 19. Phagocytosis

the cellular process of engulfing solid particles by the cell membrane to form an internal phagosome by phagocytes and protists.

Electron Micrograph of a Macrophage Phagocytosis of E. coli 20. Pinocytosis

a form of endocytosis in which small particles are brought into the cell - forming an invagination, and then suspended within small vesicles that subsequently fuse with lysosomes to hydrolyze, or to break down, the particles

An amoeba showing pinocytosis 21. Plasmolysis

The shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss from osmosis, thereby resulting in gaps between the cell wall and cell membrane.

22. Receptor-mediated Endocytosis

is a process by which cells internalize molecules (endocytosis) by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being internalized.

23. Transport Protein

is a membrane protein involved in the movement of ions, small molecules, or macromolecules, such as another protein across a biological membrane.

3-D image of sodium glucose transporter protein