Module 2 Definitions (so far) Flashcards
Resolution
The ability to be able to distinguish between two objects which are close together
Magnification
The degree to which the size of an image is larger than the object itself
Staining
The process which helps reveal or distinguish different features
Cytoskeleton
The network of protein fibres found within cells that gives structure and shape to the cell
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 e.g. hormones to help them work together to 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 molecules) or channel proteins (ions). This is a passive process.
Active transport
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 higher water potential to an area of lower water potential, down the water potential gradient across a partially permeable membrane. This is a passive process.
Solute
A solid that dissolves in a liquid
Solvent
A liquid that dissolves solids
Solution
A liquid containing dissolved solids
Cell cycle
Describes the events that take place as one parent cell divides to produce two new daughter cells which then each grow to full size
Mitosis
The process of nuclear division where two genetically identical nuclei are formed from one parent cell nucleus
Clones
Genetically identical cells or organisms derived from one parent
Differentiation
The changes occurring in cells of a multicellular organism so that each different type of cell becomes specialised to perform a specific function
Tissue
A group of similar, specialised cells of more than one type working together to perform a common specific function
Organ
A collection of tissues that work together to carry out a common specific function
Stem cells
Cells that are not differentiated and are capable of mitosis and differentiation to become other cell types
