Topic 2 - Cells Flashcards
(34 cards)
Magnification
the number of times bigger the image/drawing is compared to the object/real size
Resolution
the minimum distance needed to differentiate between 2 adjacent objects
Micrometer
1x10-6 m
Nanometer
1x10-9 m
Light microscope
A type of microscope which has a condenser, objective lens and eyepiece lens and light is passed through the thin specimen an up through the objective and eyepiece lenses to the eye
Electron microscope
Beams of electrons are used to visualize structures in a vacuum. Electrons have a smaller wavelength than light so electron microscopes have a higher resolution than light microscopes
Scanning Electron Microscope (SEM)
A type of electron microscope which bounces beams of electrons off the surface of an object to develop a 3D image of the specimen (no need therefore for thin sections).
Transmission Electron Microscope (TEM)
A type of electron microscope which asses a beam of electrons through a very thin section of specimen (which often has been stained with heavy metals to show up the fine internal structures).
Cell fractionation
The process where cells are broken up and the different organelles they contain are separated out.
Homogenation
The first stage of cell fractionation when cells are broken up by a homogeniser (blender) and organelles are released from the cell.
Ultracentrifugation
The first stage of cell fractionation when cells are broken up by a homogeniser (blender) and organelles are released from the cell.
Graticule
A series of lines on a microscope which can be used to calculate the size of objects
Eukaryote
A cell that has a membrane-bound nucleus and chromosomes. The cell also possesses a variety of other membrane-bound organelles, such as mitochondria and endoplasmic reticulum.
Organelle
A part of a cell
Nucleus
Organelle which contains the hereditary material (DNA) which codes for she synthesis of proteins in cytoplasm.
Mitochondria
Organelle where energy is released in aerobic respiration
Chloroplast
Organelle that is the site of photosynthesis
Rough endoplasmic reticulum (RER)
Organelle which provides a large surface area for the synthesis of proteins and glycoproteins and where proteins are transported that are synthesised on ribosomes
Smooth endoplasmic reticulum (SER)
Organelle where lipids and carbohydrates are synthesized, stored and transported.
Golgi
Organelle that contains a stack of membranes that make up flattened sacs (cisternae) where glycoproteins are synthesized, lipids are transported, modified and stores, proteins are packaged and lysosomes are formed.
Lysosome
Organelle formed when the vesicles produced by the Golgi apparatus contain enzymes. They are where unwanted materials & worn-out organelles are digested.
Ribosome
Organelle made of rRNA and protein where protein synthesis occurs
Cell wall
Organelle which provides mechanical strength to prevent the cell bursting under the pressure created by the osmotic entry of water, to give mechanical strength. Made of cellulose in plants and chitin in fungi.
Vacuole
Organelle which contains a solution of mineral salts, sugars, amino acids, wastes and sometimes pigments such as anthocyanins. They support herbaceous plants by making cells turgid, may provide a temporary food store and if they contain pigments they may colour petals to attract pollinating insects.
