Active Transport

• What is active transport?


  The movement of particles across a cell membrane against a concentration gradient ( i.e. from an area of lower conc. to an area of higher conc. ) using ATP released during respiration
• How does active transport differ from diffusion?

  Active transport requires energy, diffusion does not
• What is the energy source for active transport?

  Energy from cellular respiration
• Where does cellular respiration mainly occur?

  In the mitochondria
• Why do plants need to absorb water and mineral ions?

  To survive and grow
• Why can't plants absorb minerals by diffusion?

  Minerals are at higher concentration inside the cell
• What is the relationship between active transport and cellular respiration?

  Active transport requires energy from cellular respiration
• What minerals do plants need for chlorophyll production?

  Magnesium ions
• What minerals do plants need for protein production?

  Nitrates
• How does the concentration gradient affect active transport?

  Active transport moves substances against the gradient
• In the digestive system, when there's a higher conc. of nutrients in the gut, they diffuse naturally into the blood however sometimes there's a lower conc. of nutrients in the gut than in the blood
• What is the cavity of the small intestine ( where food is digested ) called?

  The lumen of the small intestine
• What do you find in the lumen? Name an example

  You find the molecules produced when food is digested and a good example of this are sugars such as glucose
• When there is a lower conc. of sugars outside cell rather than inside, they cannot diffuse into the cell so instead, the sugars are carried in by A.T. Once they are in the cell, the sugars can then be transported into the blood and carried around the body
• Mitochondria carry out respiration, providing the energy needed for A.T
• Why do plants need magnesium?

  To make chlorophyll in the leaves
• A.T allows nutrients to be taken into the blood, despite the fact that the conc. gradient is the wrong way - this is essential to prevent us from starving
• Mineral ions move into the root hair cell by A.T, since the conc. of mineral ions in the root hair cells are usually higher than in the soil. These ions are then transported to the xylem vessels and are moved to the leaf
• A.T is an active process because it requires energy from the cell
• What is the role of pump proteins in active transport?

  To move molecules against their concentration gradient
• What energy source do pump proteins typically use?

  ATP
• How does the sodium-potassium pump function in terms of ion transport?

  It transports sodium ions out and potassium ions in
• Active transport always takes place across a membrane and it also requires special proteins that sit in the membrane and transfer the molecules from one side to the other
• Cellular respiration is responsible for the all the energy that the cell uses + It stores the energy in little molecules called ATP
• ATP resembles batteries as it takes the energy from the mitochondria to different parts of the cell that need it
• The minerals that plants need are at a higher conc. inside the cell than they are outside in the soil and so they can't absorb them by diffusion. Instead, they have to use energy to absorb them by A.T against their conc. gradient
• The energy in which plants need, comes from cellular respiration which occurs the mitochondria
• Plants need nitrates to produce what?

  Proteins
• Plants need magnesium ions to produce what?

  Chlorophyll in the leaves