Life at the Cellular Level 1 Flashcards
What is every organism composed of?
Cells
What are cells?
The functional unit of all living things
Why are cells small?
To increase their surface area to volume ratio
What are the two types of cells?
Prokaryotic cell
Eukaryotic cell
What is a prokaryotic cell?
Cells that do not have a membrane bound nucleus
What is a eukaryotic cell?
Cell that consists of a cytomplasm and a defined nusleus bound by a nucleus membrane
What are some properties of prokaryotic cells?
Found in bacteria
No nuclear membrane
No mitachondria
No membrane bound structures
What are some properties of eukaryotic cells?
Found in human cells, multicellular animals and plants
Nucleus with membrane
Membrane bound structures
What are stem cells?
Undifferentiated cell which are capable of giving rise to indefinitely more cells of the same type
What are the two types of stem cells?
Pluripotent
Multipotent
What are pluripotent stem cells?
Can differentiate into all cell types of the body
What are multipotent stem cells?
Can differentiate into many cell types
What do all cells contain a complete set of?
DNA
What determines which proteins are found within a cell?
The genes within the DNA that are being expressed
What are genes?
Sequence of DNA or RNA that codes for a molecule that has a function
What happens during differentiation?
Cells pass through a series of changes where changes in gene expression are reflected by alterations of the cells structure and behaviour
What is differentiation?
Cells change from one cell type to another by expressing certain genes
What properties do cancer cells have?
Divide without any control
Fail to coordinate with normal cells
Fail to differentiate into specialised cells
Displace and replace normal cells
What are the processes of cell death?
Apoptosis
Necrosis
What is apoptosis?
Physiological, programmed cell death
What is necrosis?
Pathological cell death caused by injury or disease
What is the process of apoptosis?
- Individual cells are induced to die
- Membrane bleb, causing no damage to surrounding cells
- Within hours there is no inflammation
What is the process of necrosis?
- Groups of cells are induced to die
- Membrane ruptures causing damage to surrounding vessels
- Within days there is inflammation
What are the four types of tissues?
Epithelial
Connective
Nervous
Muscular
What are organs?
Mixture of different tissues