Chapters 3 & 4 - Cell movement Flashcards
Define Diffusion
the random movement of particles from an area of high concentration to an area of low concentration
Define net movement
the general direction of the movement of particles
If there is a high concentration of glucose outside of a cell, where will the glucose go?
inside the cell, to the area of lower concentration
What are the 3 characteristics of diffusion in living organisms?
- get and remove most substances through diffusion
- plants take in carbon dioxide to do photosynthesis
- oxygen diffuses out of the leaf
Name 3 substances that get diffused in organisms
Options:
- glucose
- sodium ions
- nitrate ions
- CO₂
- O₂
Explain the function of water in the human body
Water helps move food through, and helping dissolve food in the digestive system. It also helps remove waste through urine. Blood is 90% water.
Define Osmosis
the diffusion of water molecules through a partially permeable membrane
Why do water molecules go through the partially permeable membrane?
to even out any difference in concentration
Water molecules will go from an area of low concentration to an area of _____________.
high concentration
Define hydrostatic pressure (osmotic pressure)
the pressure exerted by a fluid due to the force of gravity acting upon it
How does the osmotic pressure increase?
if there is a higher difference in concentration, the osmotic pressure will increase
Where does the energy for net movement come from?
the kinetic energy that all particles have
Define turgor pressure
the force within a cell that squishes the cell membrane against the cell wall
Define turgid
turgid within cells makes it firm/rigid (filled cell)
Define flacid
when cells are soft and contracted due to plasmolysis
Define plasmolysis
contraction of the plant cell when it loses water from being in a hypertonic solution
Define hypertonic solution
higher concentration of solute in solution
Define active transport
the movement of particles through a partially permeable membrane from an area of low concentration to an area of high concentration
How do carrier proteins help with active transport?
the carrier proteins contract to change the direction in which an ion can go through (in and out of the cell)
What are humans made of?
- 62% water
- 16% protein
- 16% fat
- 1% carbohydrates
- 5% other (calcium & phosphorus in bones, ions)
- <1% DNA
Which elements are present in all biological molecules and which ones are in biological molecules sometimes?
carbon, oxygen and hydrogen are always in biological molecules. phosphorus and nitrogen are sometimes in biological molecules.
What would happen to an animal cell if the water potential outside the cell was too high? Why can’t this happen to plant cells?
the cell would burst because animal cells don’t have a cell wall. this could not happen to plant cells because they have a cell wall.
