Cell Structure and Function

Nucleoid : a region of the cytoplasm that is not enclosed in a membranous sac.

Lipid Bilayer : is a continuous , oily boundary that prevents the free passage of water-soulable substances across it .

Wavelenght : is the distance from the peak of one wave to the peak behind it .

Electron Microscope : use magnetic lenses to bend and diffract beams of electrons , wich cannot be diffracted through a glass lenses.

Transmission Electrons Microscope : electron pass through a specimen and are used to make images of its internal detail.

Scanning electron microscope : direct a beam of electrons back and forth across a surface of specimen , which has been given a thin metal coating.

Organelles : membrane bounded sacs.

Secretory Pathway : moves new polypeptide chains from some ribosomes through ER and golgi bodies , the on to the plasma membrane for release from the cell.

Endocytic Pathway : moves ions and molecules into the cytoplasm .

Vesicles : move substances from one organelle to the next in line .

Nuclear envelope : is a double-membrane system in which two lipid bilayers are pressed against each other.

Chromatin : the cell´s collection of DNA and all proteins associated with it.

Chromosome : is a double-stranded DNA molecule and its associated proteins , regardless of whether it is in dispersed or condensed form.

Peroxisomes : hold enzymes that digest fatty acids, amino acids , and hydrogen peroxide , a toxic metabolic product.

Cell Junction : are molecular structures where a cell sends or receives signals or materials , or recognizes and glues itself to cells of the same type.

Basal body : microtubules into the 9+2 array, then it remains below the finish array.

Pseudopods : False feet.