2. Cell Structure

• what organelles are only in a plant cell?

  cellulose cell wall, vacuole and chloroplasts
• the cell surface membrane regulates the movement of substances in and out of the cell
• the nucleus controls the cell's activities and contains the cell's genetic material
• the mitochondria is the site of aerobic respiration
• the chloroplast is the site of photosynthesis and contains chlorophyll
• the golgi apparatus processes and produces new lipids and proteins
• a golgi vesicle stores lipids and proteins made by the golgi apparatus
• a lysosome contains the digestive enzyme lysozyme and digests invading cells or breaks down old components of the cell
• a ribosome is the site of protein production
• the RER folds and processes proteins
• the SER synthesises and processes lipids
• what is the difference in the structure of the SER and the RER?

  the RER contains ribosomes on its membrane
• what organelle in eukaryotics is not surrounded by a membrane?

  Ribosome
• the cell wall supports cells and prevents them from changing shape
• the cell vacuole contains cell sap and helps to maintain pressure inside the cell and keeps the cell ridgid
• fungal cell walls are made of chitin
• plant and algal cell walls are made out of cellulose
• what organelles are found in a prokaryotic cell?

  plasma membrane, cell wall, slimy capsule, plasmids, circular DNA, flagellum
• a prokaryotes cell wall is made of the glycoprotein murein
• prokaryotic cells replicate by binary fission
• viruses use host cells to replicate themselves
• magnification = size of image/size of real object
• resolution is how well two points can be distinguished
• magnification is how much bigger the image is than the real size
• transmission electron microscopes use a beam of electrons transmitted through the specimen to form an image
• scanning electron microscopes scan a beam of electrons across the specimen
• electron microscopes have a higher resolution the optical microscopes as light has a longer wavelength
• cell fractionation separates organelles
• homogenisation is the breaking up of cells
• filtration gets rid of the big bits is the homogenate
• untracentrifugation is the separating of the organelles
• what are the conditions need in the solution when homogenising cells?

  ice cold, isotonic, buffer solution
• what are the heaviest to lightest organelles?

  Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, ribosomes.
• stages of mitosis in order?

  Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.
• mitotic index = number of cells with visible chromosomes/ total number of cells observed
• cholesterol gives the membrane stability
• diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration
• carrier proteins move large molecules across membrane by binding to them and transporting them
• channel proteins forms pores in the membrane for charged particles to diffuse through
• osmosis is the diffusion of water molecules across a partially permeable membrane from an area of higher water potential to an area of lower water potential