Biology Question and Answers: Temperature, Substrate, Concentration (Term Paper Sample)

Biology
1. The first law of thermodynamics states that energy can neither be created nor destroyed but can be transferred from a system to the surrounding. In the cleip, energy is changed from chemical energy(candle wick) to thermal energy(lit candle), heating up the copper tubing and water inside into a mechanical energy(the steam propelling the boat forward) Heat flows from the the candle to the copper tubing and finally into water. That way, energy has been transferred.
2.
The second law of thermodynamics states that the entropy of a system always increases.
If you took two beakers of the same volume of water and temperature, then drop a dye simultaneously on the beakers. You will realise that the pattern of distribution of the dye is is different but ultimately the end result will be same. An even colouration of the water in the beakers. This is what is called the randomness of Brownian motion due to increased entropy of the system.
In the second experiment, two beakers with the same amount of water, A at 30° and B at 90° were taken. A dye was added to each beaker simultaneously. The rate of diffusion of the dye was slow in beaker A and very fast in beaker B. Note that every other factor was constant except for temperature that was the only manipulating variable. Ultimately, the solutions have even distribution of the colour. This shows that the particles are propelled by thermodynamic energy. This shows that higher energy possessed by the particles increases the rate of diffusion. The distribution of the solute molucules is thus randomised throughout the entire system. Thus entropy increases.
3.
Substrates bind to the active site of enzymes to form enzyme-substrate complex. The enzyme then increases the rate of reaction by lowering the activation energy of the reaction.
Factors affecting enzymatic actions
• Temperature
• Substrate concentration
• pH
• Enzyme inhibitors
4. Differences between diffusion and Osmosis
Osmosis is the movement of solvent molecules from a region of low concentration to a region of high concentration while diffusion involves the movement of molecules down their concentration gradient.
Whereas osmosis involves only the movement of solvent molecules, osmosis involves both the movement of solutes and solvents molecules.
5.
Examples of Osmosis
•Reabsorption of water from the kidney tubules
•Osmosis when washing leads to wrinkling of hands
•Kidney dialysis
•Feeding in insectivorous plants
•Absorption of water for support by herbaceous plants
Examples of diffusion
•Perfume filling the whole room
• Diffusion of carbon dioxide into the leaves through the stomata
• Uptake of water from the soil through the root hairs
•Diffusion of oxygen from alveolar spaces into the bloodstream
•Release of oxygen into the atmosphere after light stage of photosynthesis
6.
Definitely yes. It helps in keeping the vegetables fresh and avoids wastages.
7. Red blood cells in isotonic solutions
There is a unique phenomenon when red blood cells are placed in an isotonic solution, there is no net gain or lose of water from the cell. As such, the cell neither swell nor shrink. The reason behind it is water enters and leaves the cell at the same rate because the concentration out and inside the cell is the same.
Red blood cells in hypertonic solutions
A red cell placed in a hypertonic solution will lose water by the process of osmosis and shrink, a process called crenation. Here, water moves from a region where it is highly concentrated to a region where it is lowly c...