Prokaryotic and Eukaryotic Cells

• What does cholesterols do in the cell membrane?

  Cholesterol is found within the bilayer and regulates fluidity of the membrane.
• What do ions do?

  Various ions and minerals are required for normal cellular functions. Example, Na+ and K+ are important in cell signalling.
• What are the features of prokaryotes?


  Unicellular, no-membrane bound organelles, DNA exists as a single strand, and cell-membrane is surrounded by the cell wall.
• What are the features of eukaryotes?


  Unicellular or multicellular, have a membrane bound nucleus and organelles, and DNA is contained in the nucleus.
• What is the cell membrane?

  A thin semi-permeable membrane, and controls what enters and exits the cell.
• What is the cell wall?


  Found in plant and bacterial cells, it is rigid to provide structural support, fully permeable, and located outside of the cell membrane.
• What is the nucleus?

  Is the control centre and contains DNA.
• What are ribosomes?


  They are the site of protein synthesis and attached to the rough ER or floating free.
• What is the Endoplasmic Reticulum?


  Is connected to the nuclear membrane, transport network. If it is a rough ER it works with ribosomes to make proteins. If it is a smooth ER it works on the synthesis of carbohydrates, lipids, and steroids.
• What is a Golgi apparatus?


  Stores, modifies and packages proteins into vesicles.
• What are lysosomes?


  Organelles that contain digestive enzymes and break down waste materials and cellular debris.
• What is the mitochondria?


  The powerhouse of the cell and the site of aerobic cellular respiration.
• What is chloroplast?


  Found in plant cells, contains chlorophyll, and the site of photosynthesis.
• What are other plastids?

  Found in plant cells and are important for plant cell function and survival.
• What are vacuoles?


  Fluid-filled sac which stores water, food, enzymes, wastes, pigments, etc. Plant cells contain a large central vacuole and animal cells contain many small vacuoles.
• What are centrioles?


  They aid in cell division.
• How do you identify a chloroplast?

  Is only found in plant cells, is 'bean' shaped with a clear external membrane, and has dense, dark bands connected.
• How can you identify a mitochondria?

  Is bean shaped with a clear external membrane and a clear internal membrane visible.
• How do you identify an endoplasmic reticulum?

  Is the mass of membrane structures, located centrally, and may see visible ribosomes.
• How do you identify lysosomes?

  Is small, typically circular, often no internal structures, and may be light or dark.
• What is the controlling of biochemical processes?

  Membrane-bound organelles allows compartmentalisation which enables complex + multiple metabolic reactions to occur at the same time in the cell. Organelles also often have further internal membranes.