Biology Unit 2

Transport Protein Function: cell-cell recognition, enzymatic activity, signal transduction, intercellular joining, attachment for extracellular matrix

Microtubules: biggest, made up of tubulin, centrioles, cilia, flagella

Microfilaments: smallest, actin, cytokinesis, muscle contraction, and formation of pseudopodia

Small Nonpolar Molecules: Cross-easily

Polar Unchanged Molecules: pass in small amounts

Hydrophobic Core: prevents passage ions (large polar charged molecules)

Hypotonic: lysed, turgid

Isotonic: flaccid

Hypertonic: plasmolyzed

Cotransports: secondary active transport that uses the energy from an electrochemical gradient to transport 2 different ions across the membrane through a protein

Sumport: 2 different ions are transported in the same direction

Antiport: 2 different ions are transported in opposite directions

Membranes become polarized when: ions move across them

Osmolarity: total solute concentration in a solution

Tonicity: measurement of the relative concentration of solute between 2 solutions

Osmoregulation: maintains water balance & allows control of internal solute composition

Plasmolysis: less cellular solute and more cellular water potential

Gap junctions (Cytoplasmic Channels): provide cytoplasmic channels from one cell to another cell

Desmosomes: function like rivets, fastening cells together into strong sheets (intermediate filaments anchor desmosomes in the cytoplasm)

Tight junctions: plasma membranes of neighboring cells are very tightly pressed against each other

Extracellular Matrix (ECM): glycoprotsin and other carb-cointaing molecules secreted by the cells