Bio 1408 Exam 2 Review

The given answer, "requires energy," suggests that the term "active" in this context is referring to a process that involves energy expenditure. This implies that in order for active transport to occur, energy is required. It is known that active transport is a process in which substances are moved across a cell membrane against their concentration gradient, requiring the use of energy. Therefore, the answer aligns with the understanding that active transport necessitates energy in order to function.

The correct answer is "capacity to perform work." Energy is defined as the ability or capacity to perform work, which is the transfer of energy from one object or system to another. It is the ability to cause change or do work, whether it is in the form of mechanical, thermal, electrical, or any other type of energy.

Enzymes are biological catalysts that play a crucial role in speeding up chemical reactions in living organisms. They are typically named with the suffix "-ase". Enzymes enable reactions to occur by lowering the activation energy required for the reaction to take place. This allows reactions to happen at a faster rate, making them essential for various metabolic processes in cells.

This statement is true because osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration across a semipermeable membrane. This means that when the solute concentration is high, water molecules will move in the opposite direction, from the area of lower solute concentration to the area of higher solute concentration.

The given correct answer, "law of thermodynamics," is an explanation for the statement "Energy cannot be created or destroyed, merely change forms." The law of thermodynamics, specifically the first law, states that energy is conserved in a closed system. This means that the total amount of energy in a system remains constant, and it can only change from one form to another. Therefore, the statement accurately reflects the principle of energy conservation described by the law of thermodynamics.

Enzymes are biological molecules that act as catalysts, speeding up chemical reactions in the body. They achieve this by lowering the activation energy required for a reaction to occur. Enzymes work by binding to specific substrates, forming an enzyme-substrate complex. This complex undergoes a series of interactions, causing the substrates to be converted into products. Enzymes are not consumed in the reaction and can be used repeatedly. The presence of hydrophobic and hydrophilic regions on enzymes allows them to interact with different types of molecules, facilitating the reaction process. Factors such as temperature and salinity/electrolytes can affect enzyme activity.

Enzymes are made of proteins, which can exist in either tertiary or quaternary structure. The tertiary structure refers to the three-dimensional arrangement of the protein's secondary structure elements, while the quaternary structure refers to the arrangement of multiple protein subunits in a larger complex. The question is asking about the structure of enzymes, and the correct answer indicates that enzymes are made of proteins and can have either tertiary or quaternary structure.

Hydrophilic refers to substances or molecules that are attracted to water. They have a tendency to interact or dissolve in water due to their polar or charged nature. The term "phospho-" suggests that the hydrophilic molecule contains a phosphate group, which further enhances its affinity for water. This attraction is due to the ability of water molecules to form hydrogen bonds with the hydrophilic substance. The other options mentioned, such as requiring energy, moving from high to low concentration, and having more solutes compared to blood/plasma, are not accurate explanations of hydrophilicity.

Osmosis is the correct answer because it is the form of diffusion in which water moves from an area of high to low concentration. In osmosis, water molecules move across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration, in order to equalize the concentration on both sides. This process is important for maintaining the balance of water and solutes in cells and is essential for various biological processes.

The given answer, "Hypertonic," suggests that the solution being referred to has a higher concentration of solutes compared to blood or plasma. In a hypertonic solution, there is a greater osmotic pressure, causing water to move out of the cells, resulting in cell shrinkage or dehydration. This explanation aligns with the statement that the solution has more solutes compared to blood/plasma.

Enzymes have a high degree of specificity, meaning that each enzyme is specialized to catalyze a specific substrate. This specificity allows enzymes to effectively carry out their function in the body. Additionally, the statement that "one enzyme will catalyze one substrate" further emphasizes this specificity, indicating that enzymes do not catalyze multiple substrates simultaneously. Therefore, both statements A and B are correct answers in relation to the specificity of enzymes.

The given answer, Isotonic, suggests that the solution being referred to has an equal concentration of solutes as the blood or plasma. In an isotonic solution, the concentration of solutes inside and outside of the cell is balanced, resulting in no net movement of water across the cell membrane. This means that the cell will maintain its normal shape and size without experiencing any significant changes.

Isotonic refers to a solution that has the same concentration of solutes as the cell. Animal cells prefer an isotonic environment because it allows for a balanced exchange of water and solutes across the cell membrane. In an isotonic solution, there is no net movement of water into or out of the cell, which helps maintain the cell's shape and function. This is important for animal cells as they rely on maintaining a stable internal environment to carry out their physiological processes.

All of the options listed - kinetic, potential, chemical, radiant, and thermal - are forms of energy. Kinetic energy is the energy of motion, potential energy is stored energy, chemical energy is the energy stored in chemical bonds, radiant energy is energy that travels in waves (such as light or heat), and thermal energy is the energy associated with the temperature of an object. Therefore, all of these options represent different forms of energy.

Plants prefer a hypotonic environment because it allows for the movement of water into the plant cells. In a hypotonic solution, the concentration of solutes is lower outside the cell compared to inside the cell. This creates a concentration gradient that causes water to move into the cell through osmosis, which is essential for maintaining turgidity and cell structure in plants. Plasmolysis, on the other hand, occurs in hypertonic environments where there is a higher concentration of solutes outside the cell, leading to water loss and cell shrinkage. The terms "hawatonic" and "dursatonic" are not recognized scientific terms and do not have any relevance to the question.

The given formula represents the process of cellular respiration, where glucose and oxygen are used to produce carbon dioxide, water, and ATP. This is a correct representation of the chemical equation for cellular respiration, where glucose (C6H12O6) is broken down in the presence of oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy in the form of ATP. Therefore, the answer "True" is correct.

The cell membrane is a protective barrier that surrounds the cell and regulates the movement of substances in and out of the cell. It is composed of lipids, mainly phospholipids, which form a bilayer structure. This composition allows the cell membrane to be selectively permeable, meaning it can control what enters and exits the cell. Additionally, the cell membrane actively transports substances across it, which requires energy. Therefore, both statements A and B are correct.

Exergonic reactions are those that release energy. In these reactions, the products have lower energy than the reactants, resulting in the release of energy. This energy can be in the form of heat, light, or chemical energy. Exergonic reactions are spontaneous and do not require an input of energy to occur. They are often associated with catabolic processes, such as the breakdown of food molecules to release energy for cellular activities.

The correct answer is temperature, salinity/electrolytes, pH, and environment (poisons) because these factors can all affect the structure and function of enzymes. Temperature can alter the kinetic energy of the enzyme and substrate, affecting their ability to interact. Salinity and electrolytes can disrupt the charge distribution and stability of the enzyme. pH can alter the ionization state of amino acid residues in the enzyme's active site, affecting its ability to bind to the substrate. Environmental factors such as poisons can denature or inhibit the enzyme, rendering it inactive.

Endergonic reactions are typically coupled reactions in metabolism that absorb energy. These reactions require an input of energy to proceed and are not spontaneous. Enzymes play a crucial role in facilitating endergonic reactions by lowering the activation energy required for the reaction to occur. The other options, such as dehydration synthesis and hydrophobic, do not adequately explain the concept of endergonic reactions and their relationship to metabolism.

Diffusion is the correct answer because it is the passive process in which particles or solutes move from an area of high concentration to an area of low concentration. This movement occurs due to the random motion of particles and does not require any energy input. Osmosis, on the other hand, is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. Hypotonic and hypertonic refer to the relative concentrations of solutes in a solution compared to another solution or a cell.

Passive transport refers to the movement of molecules across a cell membrane without the need for energy input. Osmosis is a specific type of passive transport where water molecules move from an area of lower solute concentration to an area of higher solute concentration. Since passive transport does not require energy, the correct answer is "No energy."

Non-competitive inhibition occurs when a molecule binds to an enzyme at a site other than the active site, causing a change in the enzyme's shape. This change in shape prevents the substrate from binding to the active site and inhibits the enzyme's activity. In this case, the molecules that vie for the same binding site on the enzyme are lipids and phospholipids. When they bind to the enzyme, the shape of the enzyme is altered, making it impossible for the substrate to fit into the binding site and carry out its reaction.

The correct answer is "all of the above" because the question is asking for the three major stages of cellular respiration and how many ATP are produced in each stage. The explanation provided lists all three stages (glycolysis, citric acid cycle, and oxidative phosphorylation) and the corresponding ATP production for each stage. Therefore, selecting "all of the above" indicates that all three stages and their ATP production are correct.

Animal cells undergo different changes in response to changes in the surrounding environment. In a hypotonic solution (hypo-), where the concentration of solutes is lower outside the cell, animal cells tend to take in water, causing them to swell and potentially burst (lysis). On the other hand, in a hypertonic solution (hyper-), where the concentration of solutes is higher outside the cell, animal cells lose water, causing them to shrink and become wrinkled (crenate). Therefore, the correct answer is "all of the above" as animal cells can both pop (lysis) in a hypotonic solution and shrivel (crenate) in a hypertonic solution.

The correct answer is "all of the above." This means that a plant cell can become limp or flaccid in an isotonic solution, where the solute concentration is equal inside and outside the cell. It can also shrivel or undergo plasmolysis in a hypertonic solution, where the solute concentration is higher outside the cell. Therefore, both of these conditions can cause changes in the plant cell's turgidity and shape.

Metabolism refers to the sum of all the chemical processes that occur within a cell or organism. It involves the conversion of nutrients into energy and the synthesis of molecules necessary for cellular function. Enzymes are proteins that catalyze these chemical reactions, hydrophobic refers to substances that repel water, and diffusion is the movement of molecules from an area of high concentration to an area of low concentration. However, only metabolism encompasses all the chemical processes within a cell or organism.

Hydrophobic refers to the property of repelling water. It is commonly used to describe substances that do not mix or dissolve in water. Lipids, such as fats and oils, are examples of hydrophobic compounds as they are insoluble in water. Therefore, the correct answer is "all of the above" because hydrophobic substances repel water and lipids are one example of such substances.

The term "hypotonic" refers to a solution that has a lower concentration of solutes compared to another solution. In this case, the answer suggests that the solution being described has fewer solutes than what is typically found in blood or plasma. This could be relevant in the context of biology or physiology, where the concentration of solutes in blood or plasma is important for maintaining cellular function.

Competitive inhibition occurs when two molecules, the substrate and the inhibitor, compete for the same binding site on the enzyme. In this case, the inhibitor molecule alters the shape of the enzyme, making it unable to bind to the substrate. This prevents the enzyme from catalyzing the reaction normally. Therefore, the correct answer is that competitive inhibitors vie for the same binding site on the enzyme.