Cells Flashcards
Extremophiles
Organisms that are able to tolerate extreme conditions
Thermophile
Can tolerate extreme temperature
Halophile
Can tolerate extreme salinity
Acidophile
Can tolerate extreme acidity
Alkalinophile
Can tolerate extreme alkalinty
Unicellular
An organism made up of a single cell
Prokaryotic cells
Are more primitive: have no nucleus or distinct organelles
Ultrastructure
The detailed structure of a biological specimen
Nuclear membrane
A double membrane with a space in-between
Autolysis
The release of enzymes so that the entire cell is digested causing it to self-destruct
Viron
Inert virus particles that only exist outside the host cell
Bacteriophage
Viruses that replicate inside bacterial cells
Differentiation
The development of different shapes and structures to carry out specific functions.
Organelles
Specialised structures within cells
A tissue
A collection of specialised cells of the same type, all working together to carry out a specific function
A system
A number of organs working together to perform a common function
Intrinsic proteins
Proteins which span the entire width of the membrane
Extrinsic proteins
Proteins that are only found on the inner or outer surface of the membrane
Glycolipids
Lipids combined with polysaccharides and play a role in cell-to-cell recognition
Glycoproteins
Proteins combined with polysaccharides and are important in cells recognising each other, some act as antigens
Diffusion
The movement of molecules (or ions) from a region of high concentration to a region of lower concentration until they are evenly spread.
Facilitated diffusion
The use of proteins to assist the movement of molecules or ions.
Passive processes
Processes that do not require the use of ATP from respiration to be carried out
Partially permeable membrane
A membrane that allows some molecules to pass but not others
Osmosis
The diffusion of water molecules from a region of high concentration to a region of lower concentration across a partially permeable membrane
Osmosis (ψ)
The diffusion of water molecules from a region of high ψ to a region of lower ψ across a partially permeable membrane
Water potential (ψ)
The measure of the relative tendency of water to move from one area to another
Solute potential (Ψs)
The measure of the reduction in Ψ due to the presence of solute molecules
Pressure potential (Ψp)
The pressure exerted on the cell contents by the cell wall and cell membrane
Hypotonic solution
A weak solution such as distilled water
Hypertonic solution
A strong solution such as saline solution
Isotonic solution
A solution with the same Ψ as the cell
Osmoregulation
The process by which cells and simple organisms maintain fluid and electrolyte balance with their surroundings.
Active transport
The uptake of molecules or ions against a concentration gradient using energy from respiration.
Endocytosis
The transport of large quantities of material (solid or liquid) into the cell
Exocytosis
The transport of large quantities of material (solid or liquid) out of the cell
Phagocytosis
The entrance of large quantities of solid material into the cell
Pinocytosis
The entrance of large quantities of liquid material into the cell
