Cell structure and function

• cytoskeleton:

  • framework of protein fibres
  • give cell its shape
  • move materials around cell
  • made of microfilaments and microtubules
• centriols:

  • cylindrical structures located near nucleus
  • involved in cell division
• Ribsomes:

  • allows for protein synthesis
  • attached to rough endoplasmic reticulum
• Endoplasmic reticulum:

  • connect nuclear membrane to cell membrane
  • rough ones have ribsomes attached
• Golgi body:

  • flattened membranes
  • modified the vestical protines for secretion from cell
• Lysosomes:

  • contains enzymes able to break down protines, lipids, nuclaic acids and some carbs
• Mitocondria:

  • releses energy for cell to use, called cellular respiration
• Cillia and Flagella:

  • tiny projections that beat back and forth to move whole cell or substance
  • Cillia: short and numerouse e.g lining of tracia
  • Flagella: longer and only one or two e.g sperm cells
• Homostasis:

  • maintanance of constant cellular environment (internal and external)
  • ensures cells function at optimim levels
• Integral protein:

  • goes all way through bi-layer
• Peripheral protein:

  • only on one side of lipid (bi-layer)
  • dosent go through whole bi-layer.
• 4 functions of cell membrane:

  1. physical barrier
  2. regulation
  3. sensitivity
  4. support
• Microfillaments:

  • move matierials around cytoplasm
  • move whole cell
• microtubules:

  • hollow rods that keep organelles in place or move them around the cell
• How to achive homeostasis in a cell:

  • taken from tissue fluid: oxygen and glucose
  • removed from cell: CO2, Water, hormones, enzymes
• Hydrophillic:

  • water loving
• Hydrophobic:

  • water hating
• Gycoprotein function:

  • cell - cell recognition
  • moniters extracellular environment
• Cytoplasm:

  • thick fluid inside the cell membrane and all the structures within the cells
  • exept nucleus
• Cytosol:

  • liquid part of cytoplasm
• Cytoskeleton:

  • framework of protein fibres
  • give cell its shape
  • move matirials around cell
  • consists of microfilaments and microtubules
• Centrioles:

  • Two cylindrical structures usually located near the nucleus
  • involved in cell division
• Nucleus:

  • contains DNA
  • seperated from the cytoplasm by nuclear membrane
  • double membrane with nuclear pores
• Ribosomes:

  • site of protein synthesis
  • can be free or attached to endoplasmic reticulum
• Endoplasmic reticulum:

  • membrane throughout cytoplasm
  • connect nuclear membrane to cell membrane
  • provides surface for chemical reaction (e.g protein synthisis)
• Golgi body:

  • flatterned membrane
  • often located near nucleus
  • modified and packages proteins for secretion out of cell
• Lysosomes:

  • contains digestive enzymes able to breakdown proteins, lipids, nucleic acids and some carbs
• Mitochondria:

  • have double membrane
  • release energy for cell through proccess of cellular respiration
• Surface area to volume:

  • larger cell = smaller SA to vol ratio
  • cannot remove enought waste
  • cannot absorb enough nutrients