Weeks 4-5 Lecture: Plant Cell Metabolism (Diffusion, Osmosis, Photosynthesis, and Respiration) Flashcards
Refers to the net movement of particles (atoms, molecules, or ions) from a region of higher concentration to a region of lower concentration as a result of random motion.
Diffusion
What are the two main types of diffusion?
- Passive diffusion
- Facilitated diffusion
Cell membranes are made of a phospholipid bilayer that has a non-polar ___, or water fearing, middle layer that is protected on both sides by polar ___, or water-loving, surfaces. Hydrophobic molecules can freely pass through a cell membrane.
hydrophobic, hydrophilic
The movement of molecules across semi-permeable membrane without the help of protein channels thus, does not require energy.
Passive diffusion
The flow of molecules down a concentration gradient across a membrane through special passageways.
Facilitated diffusion
__ is the assisted movement of a substance from a lower concentration to a higher concentration of that substance.
Active transport
A special kind of diffusion exhibiting passive transport. It is the net movement of water (the principal solvent in biological systems) by diffusion through a selectively permeable membrane.
Osmosis
__ is a movement of ions and other atomic or molecular substances across cell membranes without need of energy input.
Passive transport
__ requires the expenditure of the cell’s energy to move specific substances against their concentration gradients.
Active transport
What are the three types of solutions created by osmosis?
- Hypertonic
- Isotonic
- Hypotonic
__ and __ are passive processes that allow specific
substances to move down their concentration gradients.
Diffusion, facilitated diffusion
When a cell is placed in a solution with a solute concentration equal to that inside the cell, water molecules diffuse through the plasma membrane equally in both directions. Such solutions are said to be ___ (from the Greek iso, “equal”) – that is, they have a solute concentration equal to that in the cell.
isotonic
When a cell is placed in a solution with a solute concentration higher than that within the cell, the solution is said to be (from the Greek hyper, “over”) to the cell.
hypertonic
When a cell is placed in a solution with a solute concentration lower than that within the cell, the solution is said to be ___ (from the Greek hypo,
“under”) to the cell.
hypotonic
A __ plant cell has gaps between the cell wall and the cell membrane. This occurs when a plant cell is placed in a hypotonic solution. Water molecules move out of the cell resulting in the loss of turgor pressure.
plasmolyzed
A __ plant cell is not swollen and the cell membrane does not press against the cell wall tightly. This occurs when a plant cell is placed in an isotonic solution. There would be no net movement of water molecules between the cell and the surrounding fluid.
flaccid
A __ cell is a cell that has turgor pressure. A plant cell that is placed in a hypotonic solution would cause the water to move into the cell by osmosis, resulting in large turgor pressure being exerted against the plant cell wall.
turgid
The chemical processes that occur in a cell are collectively referred to as its ___.
metabolism
___ reactions (also called anabolism) are chemical reactions in which energy is stored in molecules.
Anabolic
___ reactions (also called catabolism) are chemical reactions in which energy is released from molecules.
Catabolic
___ is a chemical process in which a substance loses electrons.
Oxidation
___ is a chemical process in which a substance gains electrons.
Reduction
___ makes up a small portion of the electromagnetic spectrum, which is a vast, continuous range of electromagnetic radiations generated through space and matter.
Light
The portion electromagnetic from of the spectrum
380 and 760 nanometers is called the ___ because humans can see it.
visible spectrum
