Diffusion and Membrane Lab Quiz

Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. Small, nonpolar molecules like oxygen and carbon dioxide can pass through the cell membrane because they can dissolve in the lipid bilayer, while larger or charged molecules cannot pass through easily.

Chemical indicators were used to detect the presence of specific molecules. For example, iodine can be used to detect the presence of starch. The expected results would be a color change in the indicator when it comes into contact with the specific molecule.

The initial state of Cell 1 could be a higher concentration of a substance compared to the surrounding environment, while the initial state of Cell 2 could be a lower concentration. The final states would depend on the movement of molecules through the membrane. If Cell 1 had a higher concentration, molecules would diffuse out, while in Cell 2, molecules would diffuse in. The results occurred due to the process of diffusion trying to achieve equilibrium.

Molecule X could have various functions, such as being a signaling molecule, a nutrient, or a waste product. Without specific information about molecule X, it is impossible to provide a definitive answer.

Starch needs to be broken down into smaller glucose molecules to be usable by the body. It is used as a source of energy in the human diet.

Enzymes function as biological catalysts, lowering the activation energy required for a reaction to occur, thus speeding up the rate of the reaction.

The 3 steps of enzyme interactions are: 1) Enzyme and substrate binding at the active site, forming the enzyme-substrate complex. 2) Chemical reactions occur, leading to the formation of products. 3) Products are released, and the enzyme is unchanged and can be reused.

pH, temperature, and substrate concentration can affect enzyme activity. Optimal pH and temperature allow for maximum activity, while extreme pH or temperature can denature the enzyme. Increasing substrate concentration initially increases the reaction rate until all enzyme active sites are saturated.

The Lock and Key model suggests that the enzyme's active site has a specific shape that fits the substrate like a key fits into a lock. This specific fit is essential for the enzyme to catalyze the reaction.

The shape of enzymes is determined by their amino acid sequence, and this shape is crucial for their function. Any change in the shape of an enzyme can affect its activity and ability to bind to the substrate.