Outer cell Flashcards
(13 cards)
what is the classical cell theory
- all organisms made of cells
- cells are the basic units of life
- cells come from pre-existing cells that have multiplied
what is the modern cell theory
- cells contain hereditary information in their DNA, this is passed to new cells by cell division
- all cells have the same chemical composition
- energy flow occurs within cells
why is life made of cells
cells are small with a high surface area to volume ratio – high efficiency in communication
how can the surface area / volume of a cell be increased
by flattening, filaments, branching, folding
what is the purpose of compartmentalisation
provides cells with efficiency and the ability to carry out highly specialised tasks
what is the function of the cell membrane
transport and cell-to-cell communication
what is meant by the ‘fluid mosaic model’ of plasma membrane
phospholipids move within the bi-layer
most of the lipids and some proteins move laterally
what is the function of membrane transport proteins
allow for passage of select solutes across the membrane
some shuttle substances across the membrane through a change in shape
what is the function of membrane enzyme proteins
lowering the activation energy of the reaction, thereby making it much faster than they would without a catalyst
high specificity to substrates
what is the function of membrane receptor proteins
external signalling molecule -> message is passed into the cell
what is the function of cell-cell recognition
some glycoproteins serve as recognition tags and are specifically recognised by membrane proteins of other cells
what is the function of intercellular joining
neighbouring cells in tissues, organs, or organ systems often adhere, interact and communicate through direct physical contact
what is the function of attachment to cytoskeleton and ECM
can coordinate cellular changes in response to environmental signals
