Cp Biology 2 - Chapter 4 Test

The molecule pictured in the diagram is ATP (adenosine triphosphate). ATP is a nucleotide that consists of adenosine (adenine base + ribose sugar) and three phosphate groups. It is often referred to as the "energy currency" of the cell as it is involved in energy transfer and storage within cells.

A producer is an organism that is capable of producing its own source of chemical energy through the process of photosynthesis. They convert sunlight into chemical energy by using chlorophyll in their chloroplasts. This energy is then used by the organism for its own growth and survival. Examples of producers include plants and some types of bacteria. Decomposers, on the other hand, obtain their energy by breaking down dead organic matter, while chloroplast and protist are not terms that specifically refer to organisms that produce their own source of chemical energy.

During intense exercise, the body may not be able to supply enough oxygen to the muscles, leading to anaerobic respiration. This process produces lactic acid as a byproduct. Lactic acid builds up in the muscles and can cause a burning sensation, known as muscle fatigue or soreness. Therefore, lactic acid is the end product of fermentation that causes the burning feeling in working muscles.

Photosynthesis is the correct answer because it is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. During photosynthesis, plants capture energy from the sun and convert it into chemical energy stored in glucose. This process is crucial for the survival of plants and is responsible for producing oxygen, which is essential for all living organisms. Cellular respiration, the cell cycle, and mitosis are not involved in the conversion of sunlight into glucose.

Chemosynthesis is a process by which organisms convert chemical compounds into energy. Unlike photosynthesis, which uses sunlight as a source of energy, chemosynthesis relies on the oxidation of inorganic molecules, such as hydrogen sulfide or methane, to produce energy. These chemical compounds serve as the source of energy for organisms that live in extreme environments, such as deep-sea hydrothermal vents or hot springs, where sunlight is not available. Therefore, the correct answer is chemical compounds.

All cells use chemical energy because it is the fundamental form of energy that powers cellular processes. Chemical energy is derived from the breakdown of organic molecules such as glucose through cellular respiration. This energy is then used to perform various functions within the cell, including metabolism, growth, and reproduction. While some cells, such as plant cells, can also use solar energy through photosynthesis, not all cells have access to sunlight. Therefore, the statement that all cells use chemical energy is true universally.

The ATP molecule is known as the "energy currency" of cells because it stores and transfers energy. It is formed during cellular respiration and can be broken down to release energy for various cellular processes. ATP acts as a carrier of energy, providing it to different parts of the cell where it is needed. Therefore, the phrase "stores and transfers energy" accurately describes the function of the ATP molecule.

Glycolysis is the correct answer because it is the initial step in cellular respiration where glucose is broken down into pyruvate. This process occurs in the cytoplasm of the cell and does not require oxygen. Photosynthesis is the process by which plants convert sunlight into energy, while aerobic respiration and electron transport are subsequent steps in cellular respiration that require oxygen and occur in the mitochondria. Therefore, glycolysis is the specific part of cellular respiration that involves the breakdown of glucose.

In the light-dependent reactions of photosynthesis, energy is captured from sunlight by the pigment chlorophyll. This energy is then used to convert water into oxygen and produce ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy-rich molecules. These molecules are essential for the next stage of photosynthesis, the light-independent reactions, where sugars are made using carbon dioxide. Therefore, the correct answer is "Energy is captured."

The correct answer is folded inner membrane. In the diagram, structure A is shown as a folded membrane within the cell. This structure is characteristic of the inner membrane of mitochondria, which is responsible for various metabolic processes and energy production. The folding increases the surface area available for these processes to occur. The other options, such as the mitochondrial matrix, stroma, and thylakoid membrane, do not accurately describe the structure shown in the diagram.

The part labeled B in the diagram is ribose. Ribose is a type of sugar molecule that is a component of RNA (ribonucleic acid). It is a pentose sugar, meaning it has five carbon atoms. In this diagram, ribose is shown as part of a larger molecule, possibly representing its role in the structure of ATP (adenosine triphosphate), a molecule that stores and transfers energy in cells.

The diagram to the right is depicting a chloroplast, which is an organelle found in plant cells that is responsible for photosynthesis. The structure labeled C is the stroma, which is the fluid-filled space inside the chloroplast. The stroma is where the Calvin cycle, the second stage of photosynthesis, takes place. It contains enzymes and other molecules necessary for the synthesis of glucose from carbon dioxide. Therefore, the correct answer is stroma.

The part labeled C in this diagram is phosphate. Phosphate is an essential component of ATP (adenosine triphosphate), which is the primary energy source for cells. It consists of a phosphate group attached to the ribose sugar molecule in ATP. The phosphate group plays a crucial role in transferring and storing energy within cells.

The correct answer is adenosine. Adenosine is a nucleoside that consists of adenine and ribose. It is an important component of ATP (adenosine triphosphate), which is a molecule that provides energy for cellular processes. Adenosine also plays a role in signaling pathways in the body and is involved in regulating various physiological functions.

The photosystems transfer energy to the Calvin cycle through ATP and NADPH. This is because during photosynthesis, the photosystems (specifically photosystem II and photosystem I) capture light energy and use it to generate ATP and NADPH. These energy-rich molecules are then transferred to the Calvin cycle, where they are used as fuel to power the synthesis of sugars from carbon dioxide. Therefore, the photosystems play a crucial role in providing the energy necessary for the Calvin cycle to occur.

The light-dependent reactions in photosynthesis involve capturing and transferring energy from sunlight. This process occurs in the thylakoid membrane of chloroplasts, where pigments such as chlorophyll absorb light energy. This energy is then used to convert water molecules into oxygen and high-energy molecules like ATP and NADPH. These energy-rich molecules are essential for the subsequent dark reactions, or Calvin cycle, where sugars are built using carbon dioxide. Therefore, the primary function of the light-dependent reactions is to capture and transfer energy, which is crucial for the overall process of photosynthesis.

Anaerobic respiration, also known as fermentation, is the process that breaks down sugars to make ATP when oxygen is not present. This process occurs in the absence of oxygen and is a less efficient way of producing ATP compared to cellular respiration. Glycolysis, which is the first step of both aerobic and anaerobic respiration, is a part of anaerobic respiration. Photosynthesis, on the other hand, is the process by which plants convert sunlight into energy, and it does not involve breaking down sugars or producing ATP.

The mitochondrion is the correct answer because it is the organelle responsible for converting molecules from the food we eat into usable energy. It does this through a process called cellular respiration, where glucose and oxygen are broken down to produce ATP, the energy currency of the cell. The mitochondria have an inner membrane with folds called cristae, which increase the surface area for chemical reactions to occur. This energy conversion process is vital for the functioning of cells and is why mitochondria are often referred to as the "powerhouses" of the cell.

Chlorophyll is the correct answer because it is the main light-absorbing pigment found in plant leaves. It is responsible for capturing sunlight energy during photosynthesis and converting it into chemical energy. Chlorophyll molecules are located within the chloroplasts, which are the organelles where photosynthesis takes place. Thylakoids are the membrane structures within the chloroplasts where the chlorophyll molecules are embedded. Grana are stacks of thylakoids. While all of these components are involved in photosynthesis, chlorophyll is specifically the light-absorbing molecule.

The hydrogen atoms used to form water in the electron transport chain come from NADH and FADH2. These molecules are produced during the previous stages of cellular respiration, such as glycolysis and the Krebs cycle. NADH and FADH2 carry high-energy electrons and donate them to the electron transport chain. As the electrons move through the chain, they combine with oxygen to form water, while releasing energy that is used to generate ATP.

Structure B in the diagram is the mitochondrial matrix. The mitochondrial matrix is the space enclosed by the inner membrane of the mitochondria. It contains enzymes responsible for various metabolic reactions, including the citric acid cycle (Krebs cycle) and fatty acid oxidation. The matrix also contains mitochondrial DNA and ribosomes, which are involved in protein synthesis within the mitochondria. Overall, the mitochondrial matrix plays a crucial role in energy production and cellular respiration.

Glycolysis is the process that breaks down glucose into pyruvate. It occurs in the cytoplasm of cells and is the first step in both aerobic and anaerobic respiration. Pyruvate is a three-carbon molecule that is produced during glycolysis and can be further converted into acetyl-CoA, which enters the citric acid cycle. NADH is an electron carrier that is also produced during glycolysis, but it is not the three-carbon molecule formed. Citric acid is a molecule that is produced during the citric acid cycle, which occurs after glycolysis. Carbon dioxide is a waste product that is produced during cellular respiration but is not the three-carbon molecule formed by glycolysis.

The hydrogen ions for the photosystems of the light-dependent reactions come from water. During photosynthesis, water molecules are split in a process called photolysis, releasing oxygen, electrons, and hydrogen ions. The electrons are used in the photosystems to generate energy, while the hydrogen ions contribute to the establishment of a proton gradient, which is crucial for the production of ATP.

The correct answer is the breakdown of carbon-based molecules into smaller molecules. ATP is produced through cellular respiration, a process that involves the breakdown of carbon-based molecules such as glucose. During cellular respiration, glucose is broken down into smaller molecules, releasing energy that is used to produce ATP. This energy-rich molecule can then be used by cells for various metabolic processes.

When ATP molecules have a phosphate group removed, energy is released. ATP (adenosine triphosphate) is a molecule that stores and transports energy within cells. It consists of three phosphate groups attached to an adenosine molecule. When one of these phosphate groups is removed through a process called hydrolysis, ATP is converted into ADP (adenosine diphosphate) and a free phosphate group. This release of a phosphate group provides the energy needed for cellular processes such as muscle contraction, active transport, and synthesis of molecules.

ATP (adenosine triphosphate) is a molecule that stores and provides energy for cellular processes. When ATP is transformed into ADP (adenosine diphosphate), a phosphate group is removed from ATP. This process releases energy that can be used by cells for various metabolic activities. ADP can then be converted back into ATP through cellular respiration, where energy from nutrients is used to add a phosphate group back to ADP, replenishing the energy stores.

The correct answer is the citric acid cycle. The Krebs cycle is also known as the citric acid cycle because it was first discovered by Hans Krebs and it involves the production of citric acid. This cycle is a series of chemical reactions that occur in the mitochondria of cells and is an important part of cellular respiration. It plays a crucial role in the breakdown of carbohydrates, fats, and proteins to produce energy in the form of ATP.

Eukaryotes use cellular respiration for their cellular energy needs. Cellular respiration is the process by which cells convert glucose and oxygen into carbon dioxide, water, and ATP (adenosine triphosphate) molecules, which are used as a source of energy. Eukaryotes, including plants and animals, have complex cellular structures and organelles, such as mitochondria, where cellular respiration takes place. Prokaryotes, on the other hand, lack mitochondria and use different mechanisms to generate energy, such as anaerobic respiration or fermentation.

The ultimate source of energy in almost every food chain is the sun. This is because sunlight is converted into chemical energy through the process of photosynthesis by producers, such as plants and algae. This energy is then transferred to consumers, detritivores, and decomposers as they consume the producers or other organisms in the food chain. Without the sun's energy, there would be no source of energy for the food chain to sustain itself.

The Calvin cycle is not a stage of cellular respiration. It is a series of biochemical reactions that occur in the chloroplasts of plants during photosynthesis. The Calvin cycle is responsible for converting carbon dioxide into glucose, using energy from ATP and NADPH. In contrast, cellular respiration is the process by which cells break down glucose to produce ATP, and it includes stages such as glycolysis, the Krebs cycle, and the electron transport chain.

The light-independent reactions of photosynthesis, also known as the Calvin cycle, are responsible for converting carbon dioxide into glucose. In these reactions, carbon dioxide molecules are combined with other compounds to produce glucose, which is the primary energy source for plants. Oxygen is produced as a byproduct of the light-dependent reactions, not the light-independent reactions. Water is necessary for the light-dependent reactions, but not directly involved in the light-independent reactions. Cellulose is a structural component of plant cell walls and is not directly involved in the light-independent reactions. Therefore, the correct answer is carbon dioxide.

A molecule of ATP (adenosine triphosphate) is composed of adenosine, which is a combination of adenine and ribose, and three phosphate groups. This is the correct answer because ATP is a nucleotide that consists of a nitrogenous base (adenine), a five-carbon sugar (ribose), and three phosphate groups. The three phosphate groups are attached to the ribose sugar molecule and play a crucial role in storing and transferring energy within cells.

The main function of the Krebs cycle is to produce molecules that carry high-energy electrons to the electron transport chain. The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. It plays a crucial role in cellular respiration by oxidizing acetyl-CoA, derived from carbohydrates, fats, and proteins, to produce energy-rich molecules such as NADH and FADH2. These molecules then carry the high-energy electrons to the electron transport chain, where ATP (adenosine triphosphate) is generated through oxidative phosphorylation.

Cellular respiration is the correct answer because it is the process by which cells break down sugars to produce ATP (adenosine triphosphate) in the presence of oxygen. This process occurs in the mitochondria of cells and involves multiple steps, including glycolysis, the Krebs cycle, and oxidative phosphorylation. Cellular respiration is the main source of energy production in organisms that require oxygen for survival. Anaerobic respiration, on the other hand, occurs in the absence of oxygen, and glycolysis is the initial step in both aerobic and anaerobic respiration. Photosynthesis, on the other hand, is the process by which plants convert sunlight into energy, and it is not directly involved in breaking down sugars to produce ATP.

Fermentation is a metabolic process that occurs in the absence of oxygen. It is a way for cells to produce energy without the need for oxygen. During fermentation, glucose is broken down into simpler molecules, such as lactic acid or ethanol, and this process does not involve the electron transport chain. Fermentation can occur in various organisms, including bacteria, yeast, and even some animal cells. Therefore, the correct phrase about fermentation is that it takes place without oxygen.

Glycolysis is the first step in cellular respiration, where glucose is broken down into pyruvate. NADH and ATP are also produced during this process. Therefore, the correct answer is pyruvate, NADH, and ATP.

The purpose of the light reactions is to make ATP and NADPH for use in the Calvin cycle. During the light reactions, light energy is absorbed by chlorophyll and other pigments in the thylakoid membrane of the chloroplasts. This energy is used to convert ADP and inorganic phosphate into ATP, which is an energy-rich molecule used in the Calvin cycle. Additionally, the light reactions generate NADPH, which is a reducing agent that provides the high-energy electrons needed in the Calvin cycle to convert carbon dioxide into glucose.

Carbon dioxide is the correct answer because it is the end product of alcoholic fermentation that is important in the baking industry. During fermentation, yeast converts sugars into alcohol and carbon dioxide. In baking, carbon dioxide gas produced by yeast helps the dough to rise, creating a light and fluffy texture in bread and other baked goods. The carbon dioxide gas gets trapped in the dough, causing it to expand and create air pockets, resulting in a softer and more desirable texture.

ATP synthase is the correct answer because it is the enzyme located at the end of the electron transport chain. This enzyme is responsible for the production of ATP, the main energy currency of the cell. It uses the energy generated from the flow of protons down their concentration gradient to convert ADP and inorganic phosphate into ATP. This process is known as oxidative phosphorylation and occurs in the inner mitochondrial membrane in eukaryotic cells. ATP synthase plays a crucial role in generating the majority of ATP in aerobic respiration.

Cellular respiration is the process by which cells convert carbon-based molecules from food and oxygen into ATP, which is the energy currency of the cell. This process occurs in the mitochondria and releases energy that can be used for various cellular activities. The other options in the question are incorrect because they do not accurately describe the process of cellular respiration.

Photosynthesis is the process by which plants convert sunlight into energy. During this process, carbon dioxide and water are combined to produce glucose and oxygen. Glucose is a type of sugar that serves as a source of energy for the plant, while oxygen is released as a byproduct. Therefore, the correct answer is "glucose and oxygen".

In the light-independent reactions of photosynthesis, carbon dioxide enters the Calvin cycle and sugars are made. This is because the Calvin cycle, also known as the dark reactions or the light-independent reactions, is the stage of photosynthesis where carbon dioxide is converted into glucose. This process requires energy from ATP and NADPH, which are produced during the light-dependent reactions. The carbon dioxide molecules are fixed and combined with the energy-rich molecules to form simple sugars, such as glucose, which can be used by the plant for energy or stored for later use.

The electron transport chain is a series of protein complexes located in the inner mitochondrial membrane. During this process, energy from the Krebs cycle is used to transport electrons through these protein complexes. As the electrons move through the chain, hydrogen ions are pumped across the inner mitochondrial membrane, creating a concentration gradient. This gradient is essential for the production of ATP through ATP synthase, which is also located in the inner mitochondrial membrane. Therefore, the correct answer is that energy from the Krebs cycle is used to pump hydrogen ions across the inner mitochondrial membrane.

In the given diagram, the structure labeled E appears to be a stack of flattened sacs, which is characteristic of thylakoid membranes. Thylakoid membranes are found within chloroplasts and are responsible for carrying out the light-dependent reactions of photosynthesis. They contain the pigment chlorophyll, which absorbs light energy, and other components necessary for the conversion of light energy into chemical energy. Therefore, the correct answer is thylakoid membranes.

Chloroplasts are the organelles in plant cells responsible for photosynthesis. They contain chlorophyll, a pigment that absorbs sunlight. During photosynthesis, chloroplasts absorb sunlight and convert it into chemical energy in the form of glucose. This process involves the conversion of carbon dioxide and water into glucose and oxygen. Therefore, the statement "Chloroplasts absorb sunlight and store chemical energy" accurately describes the process of photosynthesis.

The Krebs cycle is a series of chemical reactions that occur in the mitochondria of cells. It is a key part of cellular respiration, which is the process by which cells convert glucose into energy. During the Krebs cycle, glucose is broken down and carbon dioxide is produced as a waste product. Additionally, ATP (adenosine triphosphate) is generated as a form of energy currency for the cell. Therefore, the correct answer is ATP and carbon dioxide.

In the diagram, the structure labeled D is the granum. A granum is a stack of thylakoid membranes found in the chloroplasts of plant cells. It is the site where the light-dependent reactions of photosynthesis occur. The thylakoid membranes contain chlorophyll, which absorbs light energy for the process of photosynthesis. The granum plays a crucial role in capturing and converting light energy into chemical energy, which is then used to produce glucose and oxygen.

Fermentation plays a crucial role in allowing glycolysis to continue producing a small amount of ATP. During glycolysis, glucose is broken down into pyruvate and NADH. In the absence of oxygen, fermentation helps regenerate NAD+ from NADH, which is necessary for glycolysis to continue. By regenerating NAD+, fermentation allows glycolysis to persist, producing a limited amount of ATP. This is particularly important in anaerobic conditions when oxygen is not available for cellular respiration.

Electrons provide the energy to operate the protein pumps in the electron transport chain. As electrons move through the chain, they transfer energy to protein complexes, which use this energy to pump hydrogen ions across the mitochondrial membrane. This creates a concentration gradient of hydrogen ions, which is then utilized by ATP synthase to generate ATP. Oxygen is the final electron acceptor in the chain, while carbon dioxide is not directly involved in providing energy for the protein pumps.

The electron transport chain in photosynthesis is a series of proteins located in the thylakoid membrane. This chain plays a crucial role in the light-dependent reactions of photosynthesis by transferring electrons and generating a proton gradient across the thylakoid membrane. This proton gradient is then used to produce ATP, which is essential for the synthesis of glucose during the Calvin cycle.