Weeks 4-5 Lecture: Plant Cell Metabolism (Diffusion, Osmosis, Photosynthesis, and Respiration)

Question 1

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.

Answer 1

Diffusion

Question 2

What are the two main types of diffusion?

Answer 2

1. Passive diffusion
2. Facilitated diffusion

Question 3

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.

Answer 3

hydrophobic, hydrophilic

Question 3

The movement of molecules across semi-permeable membrane without the help of protein channels thus, does not require energy.

Answer 3

Passive diffusion

Question 3

The flow of molecules down a concentration gradient across a membrane through special passageways.

Answer 3

Facilitated diffusion

Question 3

__ is the assisted movement of a substance from a lower concentration to a higher concentration of that substance.

Answer 3

Active transport

Question 3

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.

Answer 3

Osmosis

Question 3

__ is a movement of ions and other atomic or molecular substances across cell membranes without need of energy input.

Answer 3

Passive transport

Question 3

__ requires the expenditure of the cell’s energy to move specific substances against their concentration gradients.

Answer 3

Active transport

Question 3

What are the three types of solutions created by osmosis?

Answer 3

1. Hypertonic
2. Isotonic
3. Hypotonic

Question 3

__ and __ are passive processes that allow specific
substances to move down their concentration gradients.

Answer 3

Diffusion, facilitated diffusion

Question 3

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.

Answer 3

isotonic

Question 3

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.

Answer 3

hypertonic

Question 3

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.

Answer 3

hypotonic

Question 3

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.

Answer 3

plasmolyzed

Question 4

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.

Answer 4

flaccid

Question 4

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.

Answer 4

turgid

Question 4

The chemical processes that occur in a cell are collectively referred to as its ___.

Answer 4

metabolism

Question 5

___ reactions (also called anabolism) are chemical reactions in which energy is stored in molecules.

Answer 5

Anabolic

Question 5

___ reactions (also called catabolism) are chemical reactions in which energy is released from molecules.

Answer 5

Catabolic

Question 6

___ is a chemical process in which a substance loses electrons.

Answer 6

Oxidation

Question 7

___ is a chemical process in which a substance gains electrons.

Answer 7

Reduction