Active Transport

• What is the process of DNA replication called?

  Semiconservative replication
• What happens to DNA strands during replication?

  DNA strands unwind
• How do nucleotides align during DNA replication?

  Nucleotides line up along both strands
• What type of pairing occurs between DNA bases?

  Complementary base pairing
• What type of bonds are formed between DNA bases?

  Hydrogen bonds
• What bonds form between adjacent mononucleotides in DNA?

  Phosphodiester bonds
• What type of reaction forms phosphodiester bonds?

  Condensation reaction
• What enzyme is responsible for unwinding DNA?

  DNA helicase
• What is active transport?

  Movement against a concentration gradient
• What direction do molecules move during active transport?

  From lower to higher concentration
• What energy source is required for active transport?

  Energy from respiration
• What molecule provides energy for active transport?

  ATP
• What type of cells have many mitochondria for active transport?

  Cells involved in active transport
• How selective is active transport?

  Very selective process
• What proteins perform active transport?

  Specific carrier proteins
• How does facilitated diffusion differ from active transport?

  Facilitated diffusion does not use ATP
• What type of proteins are involved in facilitated diffusion?

  Channel or carrier proteins
• In which direction does facilitated diffusion occur?

  Down a concentration gradient
• Can active transport occur against a concentration gradient?

  Yes, it can occur against a gradient
• What is a membrane pump?

  A carrier protein that moves ions
• What happens when a molecule binds to a carrier protein?

  It causes a change in shape
• What occurs when ATP binds to the carrier protein?

  It splits into ADP and phosphate
• What happens to the phosphate after it is released?

  It combines with ADP to reform ATP
• What is bulk transport used for?

  Transporting large molecules like enzymes
• What are the two types of bulk transport?

  • Endocytosis: transport into cells
  • Exocytosis: transport outside of cells
• What is phagocytosis?

  Transport of solids into cells
• What is pinocytosis?

  Transport of liquids into cells
• What happens during endocytosis?

  The membrane invaginates around the molecule
• What forms when the membrane fuses during endocytosis?

  A vesicle
• What happens to the vesicle after it pinches off?

  It moves into the cytoplasm
• Where are vesicles usually formed for exocytosis?

  By the Golgi apparatus
• What happens to vesicles during exocytosis?

  They fuse with the cell membrane
• What is required for the movement of vesicles?

  Energy in the form of ATP
• What factors affect the rate of active transport?

  Number of carrier proteins in the membrane
• How does the speed of individual carrier proteins affect active transport?

  Faster proteins increase the transport rate
• What affects the rate of respiration and ATP availability?

  Factors that affect respiration
• How do factors affecting respiration influence active transport?

  They also affect active transport rates