Cells Flashcards
nucleus
- contains chromosomes and is protein bound
- linear DNA
- nuclear pores
RER
- series of flattened sacs
- folds and processes protein made on the ribosomes
SER
- membrane bound sacs
- produces and processes lipids
Golgi apparatus
- series of fluid filled, flattened and curved sacs with vesicles surrounding the edges
- processes and packages proteins and lipids into vesicles
- produces lysosomes
mitochondria
- bound by double membrane
- cristae
- matrix contains enzymes needed for respiration
Lysosomes
vesicles containing digestive enzymes bound by a single membrane
Cell wall
made of peptidoglycan
Viruses
- non living
- nucleic acids in capsid
- attachment protein
TEM
- beam of electrons pass through thin section of a specimen
- areas that absorb the electrons appear darker on the electron micrograph
SEM
- beam of electrons passes across surface
- builds up a 3D image depending on contours of the specimen
Ultracentrifugation
- cells homogenised and the fluid is put in a buffer that is ice cold, same water potential, pH buffer
- placed in centrifuge and spun at low speed first
- heaviest organelles form a pellet at the bottom of the tube
- remove the pellet from the supernatant and increase the speed as you centrifuge again
- repeat steps until you receive the desired organelle
Interphase
- G1= growth and replication
- S1= synthesis of DNA
- G2= error check
Mitosis
- Prophase = centrioles appear and release spindle fibres as nuclear membrane breaks down
- metaphase= spindle fibres attach at centromere and the chromosomes align at the equator
- Anaphase= centromeres divide as single fibres pull them apart and move to opposite poles
- Telophase= nuclear membrane reforms
Cytokinesis
- cytoplasm divides and two daughters cells form with identical genetic material
Mitosis is important for
growth, repair and reproduction
Binary Fissions
- Circular DNA replicates and both copies attach to the cell membrane. Plasmids also replicate
- cell membrane begins to grow between the two DNA molecules and begins to pinch inwards, dividing the cytoplasm in two
- new cells wall forms between the two DNA molecules dividing the original cell
- identical daughter cells contains single copy of circular DNA and variable number of plasmids
Viral replication
- don’t undergo cell division
- they inject their nucleic acids into another cell
- the infected host cell replicates the virus particles
Fluid Mosaic Model
integral protein- carrier proteins which allow substances to cross the membrane
glycolipids- cell surface receptors for certain molecules. allows cells to recognise one another as well as attach to form tissue
cholesterol- makes the membrane more rigid and reduces the lateral movement of phospholipids. prevents leakage of water and dissolved ions
glycoproteins- attached to extrinsic proteins… same as glycolipid
Transports
- diffusion
- osmosis
- facilitated diffusion
- active transport
- exocytosis and endocytosis
- co transport
non specific responses
inflammation
lysozyme
interferon
phagocytosis
specific immune response
Cell mediated
Humoral response
Cell mediated response
- macrophages destroys pathogen by phagocytosis and displays antigen of surface- APC
- APC interacts with Th cell and releases cytokines
- cytokine triggers mitosis to produce Th and Tk cells
- Tk detects antigen on body cell and produces perofin which causes the lysis of cells
- memory cells
Humoral Response
- macrophages destroys pathogen by phagocytosis and displays antigen of surface- APC
- APC interacts with Th cell and releases cytokines
- Tk releases another cytokine triggering the differentiation of plasma cells and divide and produces antibodies. the antibodies attach, neutralise and agglutination
- memory cells
Structure of HIV
- matrix
- RNA
- attachment proteins
- reverse transcriptase
- capsid
- lipid envelope
HIV replication
- HIV binds to proteins on Th
- capsid fuses with cell surface membrane
- RNA and reverse transcriptase enter Th cells
- reverse transcriptase coverts RNA to DNA which moves into nucleus
- Th can now produce HIV
direct ELISA
- HIV antigen bound to bottom of the vessel
- blood plasma sample added. HIV antigens bind to the antibodies with enzyme attached
- wash
- substrate added causing colour to change
indirect ELISA
- HIV antibodies bound to bottom of the vessel
- blood plasma sample added. HIV antigens bind to the antibodies
- wash
- add secondary antibodies with active sites for substrate
- wash
- substrate added causing colour to change
Monoclonal antibodies
identical antibodies that have been produced by an immune cell that has been cloned from parent cell
