previous materials

• What are the differences between Eukaryotic and prokaryotic cells? Eukaryotic cells contain membrane-bound organelles (such as the nucleus and mitochondria), while prokaryotic cells do not.
• What are hydrophilic and hydrophobic lipids? Hydrophilic (“water-loving”) or polar end and a hydrophobic (“water-fearing”) or nonpolar end.
• What are the differences between phagocytosis, Pinocytosis, active and passive transports? Phagocytosis involves the ingestion of solid material, pinocytosis is the ingestion of surrounding fluid(s). Active transport requires energy for the movement of molecules whereas passive transport does not require energy for the movement of molecules.
• Cytosol


  Contains many metabolic pathways; protein synthesis; the cytoskeleton.
• Nucleus


  Contains main genome; DNA and RNA synthesis.
• Endoplasmic reticulum (ER)


  Synthesis of most lipids; synthesis of proteins for distribution to many organelles and to the plasma membrane.
• Golgi apparatus


  Modification, sorting, and packaging of proteins and lipids for either secretion or delivery to another organelle.
• Lysosomes


  Intracellular degradation.
• Endosomes


  Sorting of endocytosed material.
• Mitochondria


  ATP synthesis by oxidative phosphorylation.
• Chloroplasts (in plant cells)

  ATP synthesis and carbon fixation by photosynthesis.
• Peroxisomes


  Oxidation of toxic molecules.
• Which of the following choices reflects the appropriate order of locations through which a protein destined for the plasma membrane travels. ER à Golgi à plasma membrane
• Actin


  Thin and flexible cytoskeletal filaments involved in cell shape determination, cell movement, cytokinesis, and the maintenance of cell structure
• Actin


  • Located beneath the cell membrane and in the cell cortex
  • Facilitated by ATP
• Microtubules


  Hollow cylindrical cytoskeletal structures involved with cell division, intracellular transport, and maintenance of cell shape
• Microtubules


  • Located in the centrosome in animal cells, extend into cilia and flagella
  • Associated with GTP
• Intermediate filaments


  Provide mechanical strength to cells and tissues, anchor organelles in place, and maintain cell shape
• Intermediate filaments


  • Found in the cytoplasm, extending from the nucleus to the plasma membrane
  • Not associated with GTP or ATP
• Differences between Actin, microtubules and intermediate filaments

  Location and role of GTP or ATP
• Enzymes


  Biological catalysts that accelerate chemical reactions within cells by lowering the activation energy required for a reaction to occur
• Factors affecting enzyme activity

  • Substrate concentration
  • pH
  • Temperature
  • Enzyme concentration
  • Presence of cofactors and coenzymes
  • Inhibitors
• Allosteric inhibition


  A non-competitive method where an inhibitor molecule binds to the allosteric site, reducing the enzyme's activity and stabilizing a lower catalytic state
• Allosteric activation


  A non-competitive process where a regulatory molecule binds to the allosteric site, enhancing the enzyme's catalytic activity even without inhibitors
• Allosteric location on the enzyme plays a role in the inhibition and activation of enzymes
• Competitive vs noncompetitive inhibition. A competitive inhibitor competes with the substrate for binding at the active site of the enzyme. A noncompetitive inhibitor binds at a site distinct from the active site.
• Main pathway for respiration. Location of Glycolysis, Krebs cycle and electron chain. The main pathway for cellular respiration in eukaryotic cells is aerobic respiration, which involves the breakdown of glucose and other organic molecules to produce energy in the form of ATP. Glycolysis occurs in the cytoplasm of the cell, Krebs cycle takes place in the mitochondrial matrix which is the innermost compartment of the mitochondria, and electron chain is located in the inner mitochondrial membrane of eukaryotic cells.
• What are the differences between light and dark reactions in photosynthesis? The light reaction is the initial stage of photosynthesis which traps light energy to produce ATP and NADPH, whereas dark reaction is the second step of photosynthesis which utilizes the energy from ATP and NADPH to produce glucose.