lesson 6

• Composed of three basic parts

  • Outermost membrane
  • Cytoplasm
  • Nucleus
• Cytoplasm


  Has solid (ORGANELLES) and liquid (CYTOSOL) components
• Nucleus


  Contains nucleolus
• Cell membrane


  • Outermost boundary of the cell
  • Regulators of the passages of molecules in and out of the cell

  
• Cell membrane composition


  Phospholipid (most abundant)<|>Cholesterol<|>Proteins<|>Carbohydrates (contacts/communicates with other cells)
• Phospholipids tend to migrate from one place to another

  Cholesterol is placed between membrane to pack and restrict the movements, modulating the fluidity and movement of membrane components

  
• Membrane proteins


  • Integral (transmembrane) proteins
  • Peripheral proteins
• Integral (transmembrane) proteins


  Directly incorporated into the cell membrane, channels, carriers and transporters, need to be disrupted to extract whatever is needed
• Peripheral proteins


  Exhibit looser association with one of the membranes, responsible for the shape of the cell and transport of substances within the cell, easily extracted from the membrane, some attract each other pulling the membrane they are attached to closer
• Spectrin


  An intracellular peripheral protein that normally forms a matrix with other proteins to stabilize the biconcave shape of RBCs, mutations can result in spherical RBCs
• Cholesterol


  Has hydrophobic ring and hydrophilic hydroxyl group, inserted among closely packed phospholipids restricting their movements and thus modulating fluidity and movement of membrane components, they need to stop them from moving to prevent delay in metabolic processes
• Carbohydrates


  Can be glycolipids or glycoproteins, generally found outside the cell membrane, may act as receptors and participate in cell adhesion and cell-to-cell interaction
• Lysosome function


  1. Chemotaxis and adherence of microbe to phagocyte

  2. Ingestion of microbe by phagocyte

  3. Formation of a phagosome

  4. Fusion of the phagosome with a lysosome to form a phagolysosome

  5. Digestion of ingested microbe by enzymes

  6. Formation of residual body containing indigestible material

  7. Discharge of waste materials

  
• Lysosomes


  Have digestive enzymes which are helpful in cleaning debris and microbes in the cell, serve to both degrade materials outside and inside the cell, break down lipids, carbohydrates, and proteins into small molecules, involved in breaking down organelles that have outlived their usefulness

  
• Mitochondria parts


  • Cristae
  • Matrix
  • Outer membrane
  • Intermembrane space
  • Inner membrane

  
• Mitochondria


  Membrane-enclosed organelle that functions for ATP production, matrix is where Krebs cycle takes place, highest in number in cardiac muscles and kidney tubules, concentrated in areas where energy is needed
• Other functions of mitochondria

  • Synthesis of steroid hormones
  • Beta-oxidation of fatty acids for energy production
  • Initiator of apoptosis
• Cellular respiration


  1. Glucose enters the cell through the action of insulin

  2. Glucose undergoes glycolysis in the cytoplasm to produce pyruvate

  3. Pyruvate enters the mitochondria and is converted into Acetyl coA

  4. Acetyl coA enters Krebs Cycle (matrix of the mitochondria)

  5. FADH2 and NADH are products of Krebs Cycle which proceed to the electron transport chain in the inner membrane

  6. Intermembrane space will have the most Hydrogen as they transfer H in the ETC, but ATP synthase will bring hydrogen back inside the matrix along with the production of ATP as a result
• Nucleus


  Control center of the cell, they have DNA, rough ER, smooth ER, lysosome, peroxisome follow nucleus, mitochondria has their own DNA
• Physical traits


  • Differences in height (growth hormone)
  • Difference in skin color (melanin)
• Growth hormone and PAH


  Proteins made of specific sequence of amino acids
• Transcription


  DNA (gene) is transcribed in the form of mRNA in the nucleus, mRNA will go the ribosome to produce proteins, gene is copied in the form of mRNA
• Translation


  In ribosomes, mRNA codes are read for protein synthesis
• Endoplasmic reticulum


  • Rough ER (with ribosomes, functions to produce proteins, continuous with nuclear membrane)
  • Smooth ER (devoid of ribosomes, lipid synthesis, drug and alcohol metabolism)
• Golgi apparatus


  Modifies, stores, and packages proteins synthesized from the RER, determines where the protein is transported, set of membrane bound sacs called cisternae, has cis face facing the rough ER and trans face where the packaged proteins exit out, proteins produced by the RER are initially immature and nonfunctional so they need to be further processed