cells ! Flashcards
longitudinal section !
cutting along long axis of cell (top to bottom)
transverse section !
cutting at right angles to the longitudinal plane (left to right)
cell surface membrane / plasma membrane !
partially permeable : allows small molecules to diffuse slowly through it
controls substances entering and leaving the cell
surrounds organelles within cell and keeps them in the cell
nucleus !
double membrane
consists of nucleoplasm, nucleolus & nuclear envelope
controls all cellular activities : cell growth & repair of worn-out parts
essential for cell division for continuity of life
cytoplasm !
contains organelles : have specialised function/structure
cell wall !
found only in plant cell made of cellulose fully permeable protects the cell from injury gives the plant its regular shape
rough endoplasmic reticulum !
consists of a network of flattened spaces lined with a membrane
continuous with nuclear envelope
appears rough : ribosomes are attached to its outer surface
transports proteins to golgi body for secretion out of cell
smooth endoplasmic reticulum !
synthesises fats & steroids
does not have ribosomes & is more tubular
involved in detoxification : converts toxic substances to harmless substances
ribosomes !
small round structures that are either attached to endoplasmic reticulum or lie freely in the cytoplasm
needed to synthesise proteins in the cell
if attached to ER : make proteins for secretion out of cell
if lie freely in cytoplasm : make proteins for use within the cytoplasm of the cell
golgi body !
disc shaped, consists of a stack of flattened spaces surrounded by membranes
chemically modifies substances made by the ER
stores & packages the substances in vesicles for secretion out of the cell
mitochondria !
plural : mitochondrion
double membrane
performes aerobic respiration : oxidises food substances to release energy for cellular activities
- growth & respiration
vacuoles !
stores substances within the cell
animal cell : many small vauoles
- contain water, food substances (glucose, amino acids), digestive enzymes (to digest bacteria)
plant cell : one large central vacuole that contains cell sap
- stores dissolved substances : sugar, water, minerals, amino acids
centrioles !
only in animal cells
small hollow cylinders close to nucleus
important for cell division
chloroplasts !
only in plants
contains a green pigment : chlorophyll
- essential for photosynthesis
…
cell -> tissue -> organ -> system -> organism
