Ch 3 & 4 Flashcards
Phospholipid bilayer
fatty acids are away from the water and phosphate groups are in contact with the water; hydrophilic heads and hydrophobic tails; very thin solution
Intrinsic proteins
proteins partially immersed in the lipid bilayer; differ in size, shape and location of hydrophobic, lipid soluable regions
Extrinsic Proteins
AKA peripheral proteins that are located outside the membrane
Hydrophilic Domains
loves water; can mix, dissolve in and interact with water; associate mostly with phospholipid phosphates and water
Hydrophobic Domains
hates water; does not mix with or repels water; associates mostly with fatty acids and allows proteins to sink
Fluid Mosaic Membrane
a heterogeneous liquid (at least some proteins are bound to their neighbors and differentiation in diffusion takes place); many types of lipids and intrinsic proteins can diffuse laterally
Glycoproteins
a protein with sugar attached (short chains less than ten sugars long)
Vesicles (lumen)
Vesicle: small space enclosed by a membrane
Lumen: interior of a vesicle
Exocytosis
when the contents of a vesicle or vacuole are carried to the outside of the cell by fusion of the plasma membrane and the membrane of the vesicle or vacuole
Endocytosis
when material is absorbed into a cell by invagination in the plasma membrane, then it pinches and shits to form a vesicle
Selectively Permeable
some substances cross the membrane more easily and rapidly than others
Facilitated Diffusion
when large intrinsic proteins across the membrane assist in the movement of charged substances and act as hydrophillic channels
Active Transport
when molecular pumps (proteins) bind to a molecule on one side of the membrane and using energy changes shape to release the molecule on the other side
Protoplasm
all the substance of a cell not including the cell wall (single cell=protoplast); mass of proteins, lipids, nucleic acids and water
Plasma membrane
the membrane that covers the surface of the protoplasm; used for protection: impermeable to harmful substances and permeable to beneficial ones
Nucleus
stores the organism’s genetic information; contains DNA, involved in inheritance, metabolism control and ribosome synthesis
Nucleoplasm
located in the nucleus DNA; substance of a cell nucleus: histones, RNA, enzymes, nucleic acids, water
Nuclear envelope
surrounds the nucleus and composed of an outer membrane and an inner membrane; separates nuclear material from the rest of the cell
Pores
Numerous small holes in the nuclear envelope that are involved in the transport of material between the nucleus and the rest of the protoplasm
Nucleolus
Organelles in the nucleus where ribosomal RNAs are synthesized and assembled into ribosomal subunits
Central Vacuole
membrane bounded space larger than a vesicle that stores material (mostly water and salts) but sometimes contain visible crystals, starch, proteins bodies, etc
Cytoplasm
consists of nucleus, vacuoles and cytoplasm
Mitochondria
eukaryotic organelles that carry out cell respiration
Plastids
organelles only in plant cells
Chloroplasts
chlorophyll-rich plastids that carry out photosynthesis
Amyloplasts
plastids that store starch