Cells and skin

• What is the smallest structural and functional unit of life?

  Cell
• How many cells does the human body have?

  50-100 trillion
• What does the different structure of cells imply?

  It implies different functions
• What is the outer boundary of a cell called?

  Plasma membrane
• What is the function of the plasma membrane?

  Separates intracellular fluid from extracellular fluid
• How does the plasma membrane's consistency compare to a solid structure?

  It has the consistency of olive oil
• What does selectively permeable mean in relation to the plasma membrane?

  It allows certain substances to pass through
• Why is the plasma membrane important for homeostasis?

  It maintains different chemical compositions between ICF and ECF
• What is the structure of the plasma membrane primarily composed of?

  Phospholipid bilayer
• How do the phosphate heads and lipid tails orient in the phospholipid bilayer?

  Heads face ECF and ICF, tails face each other
• What type of substances can pass through the plasma membrane?

  Lipid soluble substances
• What are the two types of proteins found in the plasma membrane?

  Integral and peripheral proteins
• What is the function of integral proteins?

  Transport specific substances and act as receptors
• How do peripheral proteins differ from integral proteins?

  They are not embedded throughout the membrane
• What do channel proteins transport?

  Small lipid insoluble substances
• What are leakage channels?

  Always open at both ends
• What substances can pass through leakage channels?

  Water and ions
• What are gated channels?

  Open at one end, can open or close
• What controls the opening and closing of gated channels?

  Voltage, chemically, and mechanically gated
• What substances can pass through gated channels?

  Ions like Na+, K+, Ca2+
• What do carrier proteins do?

  Transform shape to allow substances to pass
• What types of substances can carrier proteins transport?

  Lipid insoluble substances and large molecules
• What is cytoplasm?

  Watery space between plasma membrane and nucleus
• What does the cytoplasm contain?

  Cellular organelles and dissolved solutes
• What is the nucleus known as?

  Control center of the cell
• What does the nucleus contain?

  DNA and genetic materials
• What is the largest organelle in the cell?

  Nucleus
• What are organelles often compared to?

  Little organs
• What is the function of ribosomes?

  Site of protein synthesis
• What are the two types of ribosomes?

  Free ribosomes and membrane-bound ribosomes
• Where do free ribosomes produce proteins for?

  Use inside the cell
• What do membrane-bound ribosomes produce proteins for?

  Export outside the cell
• What is the function of the endoplasmic reticulum?

  Synthesis, storage, transport, and detoxification
• What are the two types of endoplasmic reticulum?

  Rough ER and Smooth ER
• What is the function of Rough ER?

  Studded with ribosomes, exports proteins
• What is the function of Smooth ER?

  Synthesis of lipids and detoxification
• What is the Golgi apparatus known for?

  Modifying, concentrating, and packaging proteins
• What does the Golgi apparatus consist of?

  Stacks of flattened sacs
• What does the Golgi apparatus form and distribute?

  Vesicles within the cell and for export
• What is the function of mitochondria?

  Cellular respiration to release energy