Lab Review: Osmosis, Enzymes, Respiration, and Photosynthesis

Vocabulary flashcards covering key biology lab topics including osmosis, tonicity, enzyme kinetics, fermentation, cellular respiration, and photosynthesis based on whiteboard study guide notes.

Osmosis

The movement of $\text{H}_2\text{O}$ across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration ("water follows the salt").

Tonicity

The relative concentrations of solute across a membrane.

Isotonic Solution

A solution in which the solute concentration is the same on both sides of the membrane.

Hypertonic Solution

A solution with a higher solute concentration relative to the other side of the membrane.

Hypotonic Solution

A solution with a lower solute concentration relative to the other side of the membrane.

Selective Permeability in Osmosis

Small molecules like water can cross the semipermeable membrane, whereas larger molecules like sucrose cannot.

Enzyme

A protein (usually ending in "-ase") that catalyzes chemical reactions by making them more likely to occur and lowering the required activation energy.

Protein Organization Levels

The four structural levels of protein organization (1^\brve, 2^\brve, 3^\brve, 4^\brve) that determine protein structure and function.

Substrate

A specific substance or molecule that binds to an enzyme's active site to undergo a reaction.

Active Site

The specific region on an enzyme where the substrate binds.

Denaturation

The process in which a protein loses its functional shape and activity due to non-optimal conditions such as extreme pH or high temperature.

Diastase Reaction

The enzymatic reaction where diastase catalyzes the breakdown of starch and water into glucose ($\text{Water} + \text{Starch} \times \text{Diastase} \rightarrow \text{Glucose}$).

Iodine Test for Starch

An indicator test for starch where a dark color indicates starch is present, and a red/brown color indicates no starch is present (starch digested).

Enzyme Activity Curves

Graphs showing how enzyme activity changes with enzyme concentration (reaching a saturation point), temperature (bell curve peaking at optimal temp), and pH (bell curve peaking at optimal pH).

Saturation Point

The point where increasing enzyme concentration no longer increases reaction rate, causing the activity curve to level off.

Aerobic Cellular Respiration

Respiration requiring oxygen that yields 30 ATP ($\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{H}_2\text{O} + 6\text{CO}_2 + \text{energy (30 ATP)}$).

Anaerobic Respiration (Fermentation)

Respiration occurring without oxygen that produces ethanol and 2 ATP ($\text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2\text{CO}_2 + 2\text{C}_2\text{H}_5\text{OH} + \text{energy (2 ATP)}$).

Fermentation Food Sources

Substrates tested for fermentation rate in yeast: glucose yields the most gas, followed by fructose and sucrose, while allulose and water yield none.

Photosynthesis

The process by which cells make food using light energy ($\text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + \text{O}_2$).

Pigment

A molecule that interacts with light and has color, such as chlorophyll a, chlorophyll b, carotene, and xanthophyll.

Retention Factor ($R_f$)

A value in paper chromatography calculated as $R_f = \frac{\text{distance pigment}}{\text{distance of solvent}}$.

Carbonic Acid Formation

The reversible reaction of water and carbon dioxide forming carbonic acid ($\text{H}_2\text{O} + \text{CO}_2 \rightleftharpoons \text{H}_2\text{CO}_3$).