Definitions Module 2 Flashcards
Resolution
The ability to distinguish between two objects that are close together
Magnification
The degree to which the size of an image is larger than the object itself
Micrometre
One millionth of a metre
Nanometre
One thousandth of a Micrometre/ one thousand millionth of a metre
Staining
The process which helps reveal or distinguish different features
Cytoskeleton
The network of protein fibres found within cells that give structure and shape to the cell
ATP
Adenosine TriPhosohate
A molecule that can be broken down/hydrolysed to release energy
Organelle
A particular structure of a cell which has a specialised / specific function
Phospholipid bilayer
The basic structural components of plasma /cell surface membranes consisting of two layers of phospholipids
Fluid mosaic model
Model of cell surface / plasma membrane structure
Cell signalling
Cells communicate with one another by signals eg. Hormones to help them work together and coordinate their actions
Diffusion
The net movement of molecules from a region of high concentration of that molecule to a region of lower concentration of that molecule down a concentration gradient. This is a passive process
Facilitated diffusion
The net movement of molecules from a region of high concentration of that molecule to a region of lower concentration of that molecule, down a concentration gradient through carrier proteins (large proteins) or channel proteins (ions). This is a passive process
Active transport
Is the movement of molecules or ions across a membrane from a region of low concentration to a region of higher concentration of that molecule, against the concentration gradient. This process uses ATP to drive the protein “pumps” within the membrane
Osmosis
The net movement of water molecules from a region of high water potential to a region of lower water potential, down the water potential gradient across a partially permeable membrane. This is a passive process
