Life at the Cellular 1 Flashcards
Describe a cell.
The functional unit of all living things.
Why are cells small?
They need a large surface area for things such as absorption and evaporation.
Give 3 features of a prokaryotic cell.
Bacteria, lack nuclear membrane, no mitochondria, no membrane bound structures.
Give 3 features of a eukaryotic cell
Human cells, multicellular animals and plants, nucleus with membrane, membrane bound structures.
What are the 2 types of stem cells?
Multipotent (can differentiate into many cell types) and pluripotent (can differentiate into all cell types).
Give the characteristics of cancer cells.
Continuously dividing, don’t co-ordinate with normal cells, don’t differentiate into specialised cells and displace and replace normal cells if not stopped.
Define apoptosis.
A central mechanism controlling multicellular development. Apoptosis is intimately coupled to cell proliferation.
Name the 4 types of tissue.
Epithelial, connective, nervous, muscle.
Define tissues.
Functional arrangement of cells.
Define organs.
Mixture of different tissues.
Define systems.
Cells or organs with similar functional roles.
What 2 components make up the cell membrane?
Lipids (amphiphatic) and proteins (span some membranes).
What are the 6 functions of the plasma membrane?
Transport, enzymatic activity, receptors for signal transduction, intercellular joining, cell-cell recognition, attachment to the cytoskeleton and extracellular matrix.
Define passive diffusion.
Concentration gradient needed, lipid soluble molecules only.
Define facilitated diffusion.
Concentration gradient needed, requires carrier proteins.
What is endocytosis?
A form of active transport in which a cell transports molecules into the cell by engulfing them in an energy-using process.
What is exocytosis?
Materials are exported out of the cell via secretory vesicles.
Define cell adhesion.
Occluding junction stops molecules from leaving the cell, all the other junctions are for separation.
Name the 2 types of adhesive junctions.
Adherens and desmosomes.
What are gap junctions?
Channels linking 2 cell cytoplasms together.
