Movement between cells

• what is diffusion?

  It is the net movement of particles from an area of high concentration to low concentration
• what are some substances that move in plants and animals?

  -Oxygen

  -Carbon dioxide

  -Dissolved food substances

  -Water
• what are the three main processes of chemicals in and out of cells

  -Diffusion

  -osmosis

  -Active transport
• what is a passive process?

  Something that doesn’t require energy
• what is a active process?

  Something that does require energy
• what is a concentration gradient?

  A difference in concentration between two areas
• what are three examples of diffusion in animals cells?

  1. gas exchange in the alveoli
  2. Movement of glucose from small intestine into blood
  3. Removal of urea from cells into blood plasma
• what is an example of diffusion in plants?

  1. Exchange of gases from the spongy layer of the leaf to the palisade cell.
• oxygen in gas exchange

  air -> alveoli -> bloodstream -> cells
• carbon dioxide in gas exchange

  cells -> bloodstream -> alveoli -> air
• what is the equation for respiration?

  Oxygen + glucose -> carbon dioxide + water
• describe diffusion in the small intestines

  1. Three small molecules have been broken down from large molecules into glucose amino acids and fatty acids
  2. This is so they can diffuse into the bloodstream from the villi
  3. The concentration of food molecules will be higher in the small intestine so the molecules would diffuse out
• describe diffusion in liver cells

  1. The liver breaks down excess amino acids into urea.
  2. Urea is therefore in a high concentration in the liver cells and low concentration in blood plasma
  3. Passes from liver cells into the blood plasma
  4. excreated by the kidneys
• describe diffusion in the leaf

  1. Plants carry out photosynthesis, they use carbon dioxide and produce oxygen
  2. Common dioxide and oxygen diffuse into an out of the leaf via the stomata that are controlled by guard cells
  3. Higher conc of co2 on the outside so diffuses inside
  4. higher conc of oxygen on the inside so diffuses outside
• what is the equation for photosynthesis?

  Carbon dioxide + water -> oxygen + glucose
• what is osmosis?

  The movement of water from a dilute solution to a concentrate solution through a partially permeable membrane.

  Down a concentration gradient
• what does hypotonic solution mean?

  A solution with a higher solute concentration than the cell

  Well, shrink because the higher concentration of water on the inside will move outside
• what does isotonic solution mean?

  A solution with the same concentration as the cell

  Stays the same
• what does hypotonic solution mean?

  isolation with the lower concentration than the cell

  Swells Higher concentration of water on the outside so moves inside
• what is the required practical for investigating osmosis?

  Investigating osmosis in potato tissue
• what is active transport?

  Movement of substances from an area of low concentration to an area of high concentration against the concentration gradient
• what does active transport require and where does it come from?

  It requires energy that comes from cellular respiration
• how does active transport work?

  The substance is attracted to the protein in the cell membrane. The protein changes shape and pushes the substances into the cell.
• what are the factors that affects the rate of diffusion?

  1. The difference in concentration.(the concentration gradient.
  2. Temperature
  3. Surface area of the membrane
  4. The diffusion distance
  5. How good the blood supply is
• what is an example of osmosis?

  A plant cell placed in water
• what is an example of active transport?

  The movement of mineral ions into root hair cells