Biology Unit 2 Cells, Photosynthesis, Respiration

The correct answer is entropy. Entropy is another name for the 2nd Law of Thermodynamics, which states that nature tends towards greater randomness or disorder.

When a cell is placed in a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell. As a result, water molecules move out of the cell through osmosis, causing the cell to lose water and shrink.

The given answer "kinetic energy, kinetic" is correct because kinetic energy refers to the energy possessed by an object due to its motion. It is the energy that an object possesses as a result of its velocity. Kinetic energy is directly proportional to the mass of the object and the square of its velocity. Therefore, the answer accurately identifies the concept of energy associated with motion.

Diffusion is the process by which particles move from an area of high concentration to an area of lower concentration. This movement occurs due to the random motion of particles and does not require any external energy input. It is a passive process that aims to equalize the concentration of particles in a given system. Diffusion plays a crucial role in various biological and physical processes, such as the exchange of gases in the lungs, the movement of nutrients across cell membranes, and the mixing of substances in a solution.

Most human enzymes work best at pH levels around 7.0 because this is the pH level of the human body, specifically the blood. Enzymes are biological catalysts that help speed up chemical reactions in the body. They are sensitive to changes in pH levels, and their activity can be affected by extreme acidity or alkalinity. Since the pH level of the human body is around 7.0, it is optimal for the functioning of human enzymes. Deviations from this pH level can lead to denaturation or loss of enzyme activity. Therefore, true is the correct answer.

The term "capacity to do work" is often used to describe energy. Energy is the ability or capacity of a system to perform work or produce a change. It can exist in various forms such as kinetic energy, potential energy, thermal energy, etc. Therefore, energy is the correct answer that aligns with the given description.

Enzymes are highly specific in terms of the molecules they act on. Each enzyme is designed to catalyze a specific chemical reaction by binding to a specific substrate. This specificity is due to the unique shape and active site of each enzyme, which allows it to interact only with certain molecules that fit into its active site. As a result, enzymes can efficiently carry out their functions without interfering with other reactions or molecules in the cell. Therefore, the statement "Enzymes are very specific in terms of the molecules they act on" is true.

Enzymes are proteins that catalyze chemical reactions in living organisms. They work by binding to specific molecules called substrates and converting them into products. The substrate is the molecule that an enzyme acts on, and it binds to a specific site on the enzyme called the active site. This interaction between the enzyme and substrate allows for the chemical reaction to occur more efficiently. Therefore, the statement that the molecule that an enzyme acts on is known as the substrate is true.

Passive transport is the correct answer because it refers to the movement of glucose in and out of cells without the use of cellular energy. This process relies on protein channels to facilitate the movement of glucose across the cell membrane, allowing it to passively diffuse from an area of higher concentration to an area of lower concentration. Active transport, on the other hand, requires the expenditure of energy to move substances against their concentration gradient.

Eukaryotes, eukaryote, and eukaryotic are the correct answers because they all refer to the more advanced type of cell that has a true nucleus and numerous organelles. Eukaryotes are organisms that are composed of eukaryotic cells, which are characterized by their complex internal structure. These cells have a membrane-bound nucleus that houses the genetic material, as well as various organelles that perform specific functions within the cell.

A vesicle that contains digestive enzymes is called a lysosome. Lysosomes are small organelles found in cells that contain various enzymes capable of breaking down different types of molecules. They play a crucial role in cellular digestion and waste removal, as they can break down proteins, carbohydrates, lipids, and other cellular debris. Lysosomes are responsible for maintaining the balance of nutrients within the cell and are involved in processes such as autophagy and apoptosis.

Active transport requires the use of a carrier protein and ATP to move molecules across a cell membrane against their concentration gradient. This process requires energy, specifically in the form of ATP, to pump molecules from an area of lower concentration to an area of higher concentration. This is in contrast to passive transport, which does not require energy and occurs down the concentration gradient. Therefore, the use of a carrier protein and ATP indicates the involvement of active transport.

An isotonic solution refers to a solution that has the same concentration of dissolved particles as a cell. This means that the concentration of solutes inside the cell is equal to the concentration of solutes outside the cell. In an isotonic solution, there is no net movement of water across the cell membrane, resulting in a stable cell volume. This is important for maintaining cellular function and preventing cell damage or bursting due to osmotic imbalances.

The net production of ATP formed in the electron transport chain is 32 molecules. This is because each NADH molecule that enters the electron transport chain can produce 3 ATP molecules, while each FADH2 molecule can produce 2 ATP molecules. Since there are a total of 10 NADH molecules and 2 FADH2 molecules produced during cellular respiration, the total ATP production is 32 molecules.

Enzymes are proteins that act as catalysts in biochemical reactions. The suffix "-ase" is commonly used to denote enzymes because it helps to identify and classify them. This suffix indicates that the molecule is an enzyme and suggests its function in the reaction. Therefore, it is true that most modern enzymes end in the suffix "-ase".

Enzymes are not lipids. They are actually proteins that act as catalysts in biochemical reactions. Lipids, on the other hand, are a class of molecules that include fats, oils, and waxes. While lipids can play a role in enzyme function, enzymes themselves are not lipids. Therefore, the statement that "Chemically all enzymes are lipids" is false.

Cilia are short hairlike strands that can be found on the surface of certain cells. They are capable of moving in a coordinated manner, which allows them to function in locomotion. Cilia are often found in the respiratory tract and reproductive system, where their movement helps to move mucus and propel sperm.

Spindle fibers are protein fibers that stretch out to grab the chromosomes and separate them during mitosis. They are responsible for ensuring that each daughter cell receives the correct number of chromosomes.

The cytoplasm is the correct answer because it is the material that fills the cell. It is a gel-like substance that contains various organelles, such as the lysosomes, smooth endoplasmic reticulum, Golgi apparatus, and flagellum. The cytoplasm plays a crucial role in supporting the organelles and facilitating various cellular processes.

The Kreb's cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. During this cycle, energy-rich molecules such as ATP are produced. The net production of ATP formed in the Kreb's cycle is 2 molecules. This means that for every round of the Kreb's cycle, 2 molecules of ATP are produced as a result of the chemical reactions.

The Golgi apparatus is responsible for packaging and sorting proteins and lipids that are synthesized in the cell. It receives these molecules from the endoplasmic reticulum and modifies them by adding sugars or other molecules. The Golgi apparatus then packages these molecules into vesicles and sends them to their appropriate destinations within or outside the cell. Therefore, it can be considered as the packaging plant of the cell.

Mitochondria are often referred to as the "powerhouse" of the cell because they are responsible for generating most of the cell's energy in the form of ATP through the process of cellular respiration. They have their own DNA and are capable of producing their own proteins, which suggests that they were once independent organisms that formed a symbiotic relationship with eukaryotic cells. Mitochondria have a double membrane, with the inner membrane being highly folded to increase surface area for ATP production. This unique structure and function make mitochondria essential for the survival and functioning of eukaryotic cells.

Chloroplasts are the center for photosynthesis in plant cells. They contain chlorophyll, a pigment that captures sunlight and converts it into chemical energy through the process of photosynthesis. This energy is then used to produce glucose, which is essential for the plant's growth and survival. Chloroplasts are unique to plant cells and are responsible for the green color of leaves. They are membrane-bound organelles that have their own DNA and can replicate independently within the cell.

Active transport is a process that requires energy to move molecules against their concentration gradient. ATP (adenosine triphosphate) is the main energy currency of the cell and is used to fuel various cellular processes, including active transport. Therefore, any type of transport that is classified as "active transport" would require the cell to use ATP as the source of energy. Glucose, protein, chlorophyll, and water are not directly involved in active transport and do not provide the necessary energy for this process.

The Kreb's Cycle is also known as the citric acid cycle. It is a series of chemical reactions that occur in the mitochondria of cells during cellular respiration. This cycle plays a crucial role in breaking down glucose and producing energy in the form of ATP. It involves the oxidation of acetyl-CoA and the release of carbon dioxide. The Kreb's Cycle is an essential part of aerobic respiration and is responsible for generating the majority of ATP produced during cellular respiration.

Enzymes are biological molecules that catalyze chemical reactions in living organisms. While they do have optimal temperature ranges at which they function most efficiently, extremely high temperatures can cause them to become denatured. Denaturation is the process in which the enzyme's structure is disrupted, leading to a loss of its catalytic activity. Therefore, the statement that enzymes work best at extremely high temperatures is false, as they will become denatured at such temperatures.

In glycolysis, a metabolic pathway that occurs in the cytoplasm of cells, glucose is broken down into two molecules of pyruvate. During this process, a small amount of ATP is produced through substrate-level phosphorylation. Specifically, for each molecule of glucose, two molecules of ATP are formed. Therefore, the correct answer is 2 ATP molecules.

Glycolysis is the initial step of cellular respiration, where a glucose molecule is broken down into two molecules of pyruvic acid. This process occurs in the cytoplasm of the cell and does not require oxygen. It is an anaerobic process that produces a small amount of ATP and NADH. The pyruvic acid molecules produced in glycolysis then enter the Krebs cycle, which is the next step in cellular respiration. Therefore, the correct answer is Cellular respiration - Glycolysis.

The cell "bilayer" refers to the structure of the cell membrane, which is composed of two layers of phospholipids. Phospholipids have a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail, which allows them to arrange themselves in a bilayer formation. This arrangement provides a barrier that separates the inside of the cell from the external environment, while also allowing certain molecules to pass through. Therefore, the correct answer is phospholipids.

Osmosis is the process of water molecules moving from an area of lower solute concentration to an area of higher solute concentration through a selectively permeable membrane. In this case, the question is describing the diffusion of water through a selectively permeable membrane, which is exactly what osmosis is. Therefore, the correct answer is osmosis.

The correct answer is "potential" and "potential energy". Potential energy is the stored energy that an object possesses due to its position or condition. It is the energy that an object has the potential to release and convert into other forms of energy. The term "potential" is often used as a shorthand for potential energy. Therefore, both "potential" and "potential energy" are correct terms to describe the stored energy in this context.

The first Law of Thermodynamics, also known as the principle of conservation of energy, states that energy cannot be created or destroyed, but it can be transformed from one form to another. This means that the total amount of energy in a closed system remains constant. Therefore, the term "conservation" accurately describes this law as it emphasizes the preservation and transformation of energy rather than its creation or destruction.

ATP, or adenosine triphosphate, is a high energy molecule that cells use as an immediate source of energy. It is often referred to as the "energy currency" of the cell because it provides the energy needed for various cellular processes. When ATP is broken down into ADP (adenosine diphosphate) and inorganic phosphate, energy is released, which can be used by the cell to perform work. Therefore, ATP is the correct answer as it fits the description of a high energy molecule that cells turn to for immediate energy.

Ribosomes are correct because they are the primary site for protein synthesis in cells. They are responsible for translating the genetic information from DNA into functional proteins. Ribosomes can be found either free-floating in the cytoplasm or attached to the rough endoplasmic reticulum. They consist of two subunits, a large and small subunit, which work together to assemble amino acids into polypeptide chains.

The correct answer is mitochondria because Kreb's cycle and electron transport, which are part of cellular respiration, occur in the mitochondria. These processes generate energy in the form of ATP, which is essential for the cell's functioning. The other options mentioned, such as pilus, nucleolus, chromatin, and peptidoglycan, are not directly involved in these processes and are not the correct answer.

Endocytosis is a transport process in which the cell membrane surrounds and engulfs a substance to form a vacuole inside the cell. Phagocytosis specifically refers to the process of engulfing solid particles. This explanation matches the given answer, which is "Endocytosis (phagocytosis)".

Both B and C are correct because photosynthesis consists of two main reactions: the light reaction and the dark reaction. The light reaction takes place in the chloroplasts and converts light energy into chemical energy in the form of ATP and NADPH. The dark reaction, also known as the Calvin cycle, takes place in the chloroplasts as well and uses the ATP and NADPH produced in the light reaction to convert carbon dioxide into glucose. Therefore, both B (photosynthesis - light reaction) and C (photosynthesis - dark reaction) occur in the chloroplasts of the cell.

During the process of cellular respiration, glucose is broken down in a series of reactions to release energy. This energy is used to generate ATP molecules, which are the primary source of energy for cells. Each molecule of glucose produces a net gain of 38 ATP molecules through the processes of glycolysis, the Krebs cycle, and oxidative phosphorylation. Therefore, the correct answer is 38.

Vacuoles are large, membrane-bound storage chambers found in cells. They play a crucial role in storing various substances such as water, ions, and nutrients. Vacuoles also help maintain the cell's turgor pressure and regulate the pH balance within the cell. They can also store waste products and toxins, protecting the cell from potential harm. In plant cells, vacuoles are particularly important for maintaining the shape and structure of the cell, as well as storing pigments and other molecules. Overall, vacuoles are essential organelles involved in storage and maintenance functions within the cell.

A flagellum is a long whiplike strand that is used for locomotion. It is a structure found in certain cells, such as bacteria and sperm cells, and helps them move through their environment. Unlike cilia, which are shorter and more numerous, a flagellum is a single, long appendage. It is not a pilus, which is a short, hair-like structure used for attachment or conjugation. The cytoskeleton refers to the network of protein filaments within a cell that provides structural support and helps with cell movement, but it is not specifically a whiplike strand used for locomotion like a flagellum.

When a cell is placed in a hypotonic solution, it means that the concentration of solutes outside the cell is lower than inside the cell. As a result, water molecules will move into the cell through osmosis, causing the cell to swell. This is because the water moves from an area of low solute concentration (outside the cell) to an area of high solute concentration (inside the cell) in an attempt to equalize the concentrations. Therefore, the correct answer is that the cell would swell.

Cellular respiration is a process that occurs in the mitochondria of cells, where glucose is broken down to produce ATP (energy) for the cell. The process involves three main stages: glycolysis, the Kreb's cycle, and the electron transport chain. The electron transport chain is the final stage of cellular respiration, where electrons from the previous stages are transferred along a series of proteins and enzymes, ultimately leading to the production of ATP. Therefore, the given answer "Cellular respiration - Electron transport chain" is correct as it accurately identifies the stage that involves an electron transport chain.

During the light reaction of photosynthesis, water molecules are split through a process called photolysis. This splitting of water releases oxygen as a byproduct. The light reaction occurs in the thylakoid membranes of the chloroplasts, where light energy is absorbed by chlorophyll and converted into chemical energy in the form of ATP and NADPH. This energy is then used in the dark reaction (also known as the Calvin cycle) to convert carbon dioxide into glucose. Therefore, the correct answer is Photosynthesis - Light reaction.

Glycolysis is the initial step in cellular respiration, where glucose is broken down into two molecules of pyruvate. This process takes place in the cytoplasm of the cell. It does not require oxygen and is therefore considered an anaerobic process. Glycolysis is the first stage of cellular respiration and is common to both aerobic and anaerobic respiration. It is the main source of ATP production in anaerobic organisms and also provides the starting material for the Krebs cycle in aerobic organisms.

Cell metabolism refers to the sum of all chemical reactions taking place in the cell. It includes both catabolic reactions (breaking down molecules to release energy) and anabolic reactions (building up molecules using energy). This process is essential for maintaining cellular functions and energy production. Kinetics refers to the study of reaction rates, cellular energy refers to the energy used by the cell, and metabolic cell rate is not a commonly used term in biology. Therefore, the most appropriate answer is cell metabolism.

The dark reaction, also known as the Calvin cycle, is a part of photosynthesis that occurs in the stroma of chloroplasts. It does not require light directly and is responsible for converting carbon dioxide into glucose. This process is essential for the production of carbohydrates and other organic compounds in plants. Unlike the light reaction, which requires light energy to produce ATP and NADPH, the dark reaction can occur in the absence of light. Therefore, it is often referred to as the "light independent reaction" of photosynthesis.

A pilus is a hollow tube used by bacteria for sexual reproduction. It is a structure that extends from the bacterial cell and allows the transfer of genetic material between bacteria during conjugation. This process helps in the exchange of genetic information and promotes genetic diversity among bacteria. The other options mentioned in the question, such as flagellum, peptidoglycan, and smooth endoplasmic reticulum, do not play a role in sexual reproduction by bacteria.

Both B and C are correct because both the Kreb's Cycle and the Electron transport chain of cellular respiration take place in the mitochondria of the cell. The Kreb's Cycle occurs in the mitochondrial matrix, while the Electron transport chain occurs in the inner mitochondrial membrane. These two processes are essential for the production of ATP, the energy currency of the cell.

Enzymes are biological molecules that act as catalysts in various chemical reactions. While it is true that many enzymes are proteins, not all enzymes are proteins. Some enzymes, known as ribozymes, are made up of RNA instead of proteins. These RNA molecules are capable of catalyzing specific reactions, just like protein enzymes. Therefore, it is incorrect to say that chemically all enzymes are proteins, as there are exceptions to this rule.

The process described in the question is known as the sodium-potassium pump. This pump actively transports sodium ions out of the cell and potassium ions into the cell, creating a concentration gradient across the cell membrane. This is an essential process for maintaining the resting potential of nerve cells and is crucial for proper nerve function.