Study Exam 2 Flashcards
Diffusion def
a passive process of transport of low-molecular-weight material down its concentration gradient
Concentration Gradient def
when the concentration of particles is higher in one area than the other
Passive Transport def
a method of transporting material that does not require energy
Direct Diffusion def
the substance moves through a semipermeable membrane or in a solution without any help from transport proteins.
Facilitated diffusion def
a passive movement of molecules across the cell membrane from the region of higher concentration to the region of lower concentration by means of a carrier molecule.
Osmosis def
Transport of water via aquaporin
What solute do animals have dissolved in our cells
~0.9
What will happen when you place an animal cell in a container of 100% distilled water?
Water will move into the cell and the cell will explode because the concentration of water is higher outside the cell than inside, so water moves in; then concentration of water in cell increases; water moving in increases cell volume causing it to explode
Isotonic def
Healthy balance of water and solutes(1 water leaves, another enters)
Hypertonic def
More solutes than water
Hypotonic def
Less solutes in the cell than water.
Active transport def
Active transport proteins pump molecules against their concentration gradients using ATP
difference between active and passive
Active transport requires ATP and moves against the concentration gradient, Passive transport does not use ATP and moves along the concentration gradient
Similarities between Active and Passive
both move oxygen, water and nutrients into cells and remove waste products.
10) Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
a. protein
b. cholesterol
c. carbohydrate
d. phospholipid
a) protein
11) The tails of the phospholipids of the plasma membrane are composed of _____ and are _______?
a. phosphate groups; hydrophobic
b. fatty acid groups; hydrophilic
c. phosphate groups; hydrophilic
d. fatty acid groups; hydrophobic
d) fatty acid groups; hydrophobic
12) Water moves via osmosis _________.
a. throughout the cytoplasm b. from an area with a high concentration of other solutes to a lower one c. from an area with a low concentration of solutes to an area with a higher one d. from an area with a low concentration of water to one of higher concentration
c) from an area with a low concentration of solutes to an area with a higher one
13) The principal force driving movement in diffusion is __________.
a. temperature b. particle size c. concentration gradient d. membrane surface area
c) concentration gradient
14) Active transport must function continuously because __________.
a. plasma membranes wear out b. cells must be in constant motion c. facilitated transport opposes active transport d. diffusion is constantly moving the solutes in the other direction
D) diffusion is constantly moving the solutes in the other direction
In the context of cell biology, what do we mean by form follows function? What are at least two examples of this concept?
one can deduce the function of a structure by looking at its form, because the two are matched. Two examples: Bird, fish
Why is it advantageous for the cell membrane to be fluid in nature?
It has a very bitter taste, which discourages consumption by insects and animals.
Why does osmosis occur?
When there is a concentration gradient of a solute within a solution, but the membrane does not allow diffusion of the solute.
Where does the cell get energy for active transport processes?
From ATP produced by its metabolism
Energy def
the capacity to cause change
Potential energy def
Energy an object has bc of its location or structure
Kinetic energy def
energy of motion
What do all energy conversions generate?
Heat
Where does all energy come from?
the sun
Heat def
a type of kinetic energy contained in the random motion of atoms and molecules
Metabolism def
the total of all the chemical reactions in an organism
Endergonic rxns def
energy absorbed from the surroundings
Anabolic def
small molecules are built into large ones(energy required)
Exergonic rxns def
energy is released to the surroundings
Catabolic def
Large molecules are broken down into small ones. (energy is released)