DNA, enzymes and cells Flashcards
what are prokaryotic cells
the simplest kind of cells. only seen in bacteria and archaea
what are eukaryotic cells
more complex cells seen in animals, plants, fungi and protists
what is the plasma membrane
the surrounding structure of the cell
what is the nucleolus
a structure in the nucleus responsible for the production of ribosomal RNA(rRNA) and the assembly of the 2 ribosome subunits
what is the nuclear envelope
the external membrane of the nucleus
what are polysomes
groups of ribosomes making the same protein
what is the golgi apparatus
the packaging plant of the cell
what are lysosomes
specialized vesicles to contain digestive enzymes used in the breakdown of molecules
what are vacuoles
specialized vesicles to contain/store molecules, particularly water
what is cellular respiration
energy creation in the cell
what is the cell membrane composed of
a phospholipid bilayer and many proteins and other molecules embedded and distributed all over
describe the appearance and behaviour of the cell membrane
it is fluid-mosaic; fluid because most of the individual proteins and phospholipids can drift, and mosaic-like because it is composed of a number of different proteins and other molecules that resemble a mosaic
describe the bilayer structure of the cell membrane
phospholipids(make up the largest part. the hydrophilic heads point toward the inside and outside of the cell where they interact with water), glycolipids(similar in structure, these have a carbohydrate chain attached to the polar head), glycoproteins(proteins with a carbohydrate chain), cholesterol(a steroid that restrains movement of the phospholipids and hinders close packing) and membrane proteins
what are the functions of membrane proteins
cell recognition(using carbohydrate chains), transport, reception(binds to molecules), and enzymatic activity(catalyzes a specific reaction)
what is endocytosis
it is when cell membranes form a vesicle around the molecules that it wants to take into the cell
