Apologia Biology Quiz 5

The correct answer is 3 or three because the chemical formula of water, H2O, indicates that there are two hydrogen atoms (H) and one oxygen atom (O) in each molecule of water. Therefore, the total number of atoms in one molecule of water is three.

In a dehydration reaction, water is removed. Dehydration reactions involve the removal of a water molecule from a larger molecule, resulting in the formation of a new compound. This process is commonly observed in biological systems and is important for the synthesis of many complex molecules such as proteins, carbohydrates, and lipids. By removing water, dehydration reactions can help form stronger chemical bonds and contribute to the overall stability and structure of molecules.

The three phases of matter are solid, liquid, and gas.

In a carbohydrate, the number of atoms of hydrogen is twice the number of atoms of oxygen. This is because the chemical formula of a carbohydrate typically follows the ratio of Cx(H2O)y, where for every carbon atom (C), there are twice as many hydrogen atoms (H2) as there are oxygen atoms (O). Therefore, the correct answer is two or 2.

The three things that make up an atom are protons, electrons, and neutrons.

In a chemical reaction, the products appear on the right side of the equation. This is because a chemical equation represents the transformation of reactants into products. The reactants are written on the left side of the equation, and the products are written on the right side.

Organic molecules are the building blocks of life and are composed primarily of carbon. Carbon has the unique ability to form stable covalent bonds with other carbon atoms and a variety of other elements, such as hydrogen, oxygen, nitrogen, sulfur, and phosphorus. This versatility allows carbon-based molecules to form a wide range of complex structures and perform essential functions in living organisms. Helium and sodium do not have the ability to form the necessary bonds to create organic molecules, making carbon the correct answer.

Unsaturated fats are lipids made from fatty acids that have at least one double bond between carbon atoms. This double bond causes the fatty acid chain to have a kink or bend, which prevents the molecules from packing tightly together. As a result, unsaturated fats tend to be liquid at room temperature and are commonly found in plant-based oils. In contrast, saturated fats have no double bonds between carbon atoms and are typically solid at room temperature.

Atoms are the basic building blocks of matter. They are the smallest units of an element that retain the chemical properties of that element. Atoms combine together to form molecules, which are the smallest units of a compound that retain the chemical properties of that compound. Elements, on the other hand, are substances made up of only one type of atom. Therefore, atoms are the fundamental units from which all matter is composed.

An atom with 7 electrons must have 7 protons in order to maintain electrical neutrality. The number of protons in an atom determines its atomic number, which is a unique identifier for each element on the periodic table. Therefore, if an atom has 7 electrons, it must also have 7 protons.

Carbon-14 is an isotope of carbon, which means it has the same number of protons (6) but a different number of neutrons. The atomic number of carbon is 6, so it always has 6 protons. The atomic mass of carbon-14 is 14, which means it has a total of 14 nucleons (protons + neutrons). Since we know that carbon-14 has 6 protons, we can subtract that from the atomic mass to find the number of neutrons. 14 - 6 = 8. Therefore, carbon-14 has 8 neutrons.

Lactose is a disaccharide carbohydrate composed of glucose and galactose. In its chemical formula, C12HxO11, the number of carbon atoms is fixed at 12, and the number of oxygen atoms is fixed at 11. Therefore, the value of x must be the number of hydrogen atoms present in lactose, which is 22.

A model is a representation of something that cannot be seen. It is a simplified version or a smaller scale representation of an object, system, or concept. Models are used to understand or study complex ideas or phenomena that are not easily observable or accessible. They help in visualizing and explaining these concepts, making them more tangible and easier to comprehend.

In diffusion, both solvent and solute can randomly flow through the membrane. Diffusion is the process by which particles move from an area of higher concentration to an area of lower concentration. In this process, both the solvent (the substance in which the solute is dissolved) and the solute (the substance being dissolved) can move through the membrane. This movement occurs randomly, without any external force or energy input. Therefore, the statement is true.

A solution with a pH of 12.5 is considered alkaline. pH is a measure of the acidity or alkalinity of a solution, with values below 7 indicating acidity, 7 indicating neutrality, and values above 7 indicating alkalinity. Since the pH of the solution is 12.5, which is greater than 7, it falls into the alkaline range.

Molecules are formed when atoms bond together. Atoms are the basic building blocks of matter, and when they combine, they form molecules. Molecules can be made up of the same type of atoms or different types of atoms. They are the fundamental units of chemical compounds and play a crucial role in determining the properties and behavior of substances. Therefore, molecules are the correct answer as they represent the chemicals that result from atoms linking together.

Osmosis is the correct answer because it refers to the movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane. This process occurs in order to equalize the concentration of solute on both sides of the membrane.

Isomers are two or more molecules that have the same chemical formula but different structural arrangements. This means that they have the same number and types of atoms, but the atoms are arranged differently within the molecule. Isomers can have different physical and chemical properties due to their different structures, even though they have the same chemical formula.

A catalyst is a substance that can alter the speed of a chemical reaction, such as photosynthesis, without being consumed or used up in the process. It works by providing an alternative pathway for the reaction to occur, lowering the activation energy required for the reaction to take place. This allows the reaction to proceed at a faster rate without the catalyst being changed or depleted in the process.

To change a substance from one phase to another, heat needs to be added or removed. Adding heat to a substance can cause it to transition from a solid to a liquid (melting) or from a liquid to a gas (vaporization). On the other hand, removing heat from a substance can cause it to transition from a gas to a liquid (condensation) or from a liquid to a solid (freezing). Therefore, adding or removing heat is necessary to induce a phase change in a substance.

Proteins are made up of amino acids, which are the basic building blocks. Amino acids are organic compounds that contain an amino group and a carboxyl group. They are linked together through peptide bonds to form long chains, called polypeptides, which then fold into complex three-dimensional structures to become functional proteins. Lipids are another type of biomolecule, but they are not the building blocks of proteins. Enzymes, on the other hand, are proteins themselves and are involved in catalyzing chemical reactions in the body. Therefore, the correct answer is amino acids.

In a chemical reaction, the reactants appear on the left side of the equation. This is because the reactants are the substances that undergo a chemical change and are transformed into products. The left side of the equation represents the starting materials or the substances that are present before the reaction takes place. The right side of the equation represents the products, which are the new substances formed as a result of the reaction. Therefore, the reactants are always written on the left side of the chemical equation.

A solution with a pH of 5 is considered acidic. pH is a measure of the acidity or alkalinity of a solution, with values below 7 indicating acidity. As 5 is lower than 7, it falls into the acidic range.

Physical changes in matter are generally reversible because they do not involve a change in the chemical composition of the substance. In physical changes, the molecules or atoms rearrange themselves but do not form new substances. Examples of physical changes include melting, freezing, boiling, and dissolving. These changes can often be reversed by applying the appropriate conditions or processes, such as cooling or evaporating. Chemical changes, on the other hand, result in the formation of new substances with different properties and are usually irreversible.

A molecule can indeed have more than one structural formula. This is because structural formulas represent the arrangement of atoms in a molecule, and different arrangements can result in different structural formulas. Isomers are a prime example of this, where molecules have the same molecular formula but different structural formulas due to variations in the arrangement of atoms. Therefore, it is true that a molecule can have more than one structural formula.

The two nucleotide chains that make up DNA are held together because the nucleotide bases link together in a process known as hydrogen bonding. Hydrogen bonding occurs between the complementary base pairs adenine (A) and thymine (T), as well as between guanine (G) and cytosine (C). This bonding is important for maintaining the structure and stability of the DNA molecule, as well as for allowing the separation of the two strands during DNA replication and transcription.

Two different molecules can have the same chemical formula because the chemical formula only represents the types and numbers of atoms present in a molecule, not the arrangement or connectivity of those atoms. Isomers, for example, are molecules with the same chemical formula but different structural arrangements. Therefore, it is possible for two different molecules to have the same chemical formula.

Hydrolysis is the correct answer because it is a chemical process that breaks down complex molecules by adding water to them. In hydrolysis, the water molecule is split into its hydrogen and hydroxide ions, which react with the molecules being broken down, causing them to separate into simpler components. This process is commonly used in biological systems to break down large molecules like carbohydrates, proteins, and fats into their individual building blocks for energy or other purposes.

Biosynthesis refers to the process in which living organisms use small molecules to create larger molecules. This process involves the synthesis of complex molecules such as proteins, carbohydrates, and lipids. Osmosis and diffusion, on the other hand, are not related to the creation of larger molecules but rather involve the movement of molecules from an area of high concentration to an area of low concentration. Therefore, the correct answer is biosynthesis.

A bond that links amino acids together in a protein is called a peptide bond. This bond forms between the carboxyl group of one amino acid and the amino group of another amino acid, resulting in the formation of a peptide chain. Peptide bonds are covalent bonds and are essential for the structure and function of proteins. Hydrogen bonds, on the other hand, are weak bonds that form between the hydrogen atom of one molecule and an electronegative atom of another molecule. Chemical bond is a general term that encompasses various types of bonds, including peptide bonds.

The charge of an electron is negative. This is a fundamental property of electrons, which are subatomic particles that orbit the nucleus of an atom. Electrons have a charge of -1, while protons, which are also found in the nucleus, have a charge of +1. The negative charge of electrons is balanced by the positive charge of protons, resulting in an overall neutral charge for atoms.

When a substance undergoes a physical change, its state or form is altered, but its chemical composition remains the same. In this case, by changing a substance from one phase to another, such as from a solid to a liquid or a gas, it is undergoing a physical change. The molecules in the substance are rearranging themselves, but no new substances are being formed. Therefore, the correct answer is physical change.

The two helix strands of DNA can unravel. This process, known as DNA denaturation, occurs when the hydrogen bonds between the base pairs break, causing the two strands to separate. This unraveling is a crucial step in DNA replication, transcription, and other cellular processes.

Enzymes are a special class of proteins that act as catalysts for many chemical reactions in living organisms. They speed up the rate of these reactions by lowering the activation energy required for the reaction to occur. Enzymes are highly specific and can only catalyze specific reactions. They play a crucial role in various biological processes such as digestion, metabolism, and DNA replication. Without enzymes, these reactions would occur too slowly to sustain life. Therefore, enzymes are essential for the chemical reactions that support life.

In osmosis, only the solvent, not the solute, can pass through the membrane. Osmosis is the movement of solvent molecules from an area of lower solute concentration to an area of higher solute concentration, across a selectively permeable membrane. The solute molecules are too large to pass through the membrane, so only the solvent molecules are able to flow through. Therefore, the statement that both solvent and solute can randomly flow through the membrane is incorrect.

The vast majority of an atom's properties are determined by its electrons. Electrons are negatively charged particles that orbit around the nucleus of an atom. They are responsible for the atom's chemical behavior, as they participate in chemical reactions and bonding with other atoms. Electrons also determine the atom's size, shape, and overall reactivity. Protons and neutrons, on the other hand, are located in the nucleus and primarily contribute to the atom's mass and stability.

Two atoms of the same element can have different numbers of neutrons because isotopes of an element have the same number of protons and electrons but different numbers of neutrons. Isotopes are atoms of the same element with different mass numbers, which is determined by the number of neutrons in the nucleus. Therefore, the statement that two atoms of the same element can have different numbers of neutrons is correct.

The nucleotide base determines the "morse code" of DNA because it is the specific sequence of these bases that carries the genetic information. The order of the nucleotide bases, which include adenine, thymine, cytosine, and guanine, determines the genetic code and instructions for building proteins. Each base pairs with a specific complementary base (adenine with thymine, and cytosine with guanine), forming the double helix structure of DNA. This sequence of bases acts as a code that can be translated into proteins and ultimately determines the characteristics and functions of living organisms.

When one substance is dissolved in another, it undergoes a physical change known as a solution. In a solution, the solute (substance being dissolved) disperses evenly throughout the solvent (substance doing the dissolving), resulting in a homogeneous mixture. This process is called dissolution, and it can occur in both solid, liquid, and gas phases. The resulting solution can have different concentrations depending on the amount of solute dissolved in the solvent. Diffusion, on the other hand, refers to the movement of particles from an area of higher concentration to an area of lower concentration.

Diffusion is the process of random motion of molecules from an area of high concentration to an area of low concentration. In this process, molecules move freely and spread out evenly to achieve equilibrium. This movement occurs due to the random thermal motion of molecules. 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. Therefore, diffusion is the correct answer as it accurately describes the random movement of molecules from high to low concentration.

An element is a collection of atoms that all have the same number of protons. Each element on the periodic table is represented by a unique number of protons in its atoms. This means that all atoms of a particular element have the same number of protons in their nucleus. Therefore, the correct answer is element.

Saturated fat is a type of lipid that is made from fatty acids with no double bonds between carbon atoms. This means that the carbon atoms in the fatty acid chains are fully saturated with hydrogen atoms. This type of fat is usually solid at room temperature and is commonly found in animal products such as meat and dairy. Consuming excessive amounts of saturated fat has been linked to an increased risk of heart disease.

Hydrolysis is a chemical reaction in which a compound reacts with water to break apart into smaller molecules. In the case of a disaccharide, which is a molecule made up of two sugar units, hydrolysis would break the bond between the two sugar units, resulting in the formation of two monosaccharides. Therefore, the correct answer is monosaccharides.

The properties of a protein are determined by the type of amino acids present, the order in which they are arranged, and the number of amino acids in the protein. The type of amino acids affects the chemical properties of the protein, such as its hydrophobicity and charge. The order of amino acids determines the protein's primary structure, which in turn influences its secondary, tertiary, and quaternary structures. The number of amino acids affects the size and length of the protein, which can impact its function and stability. The color and shape of amino acids are not factors that determine the properties of a protein.

Photosynthesis is the process by which plants convert sunlight, water, and carbon dioxide into glucose, which is their source of energy. Sunlight is necessary as it provides the energy needed for the reaction to occur. Water is essential for the plants to undergo photosynthesis and acts as a source of hydrogen for the reaction. Chlorophyll or other catalysts are required to capture the energy from sunlight and initiate the chemical reactions. Carbon dioxide is needed as a source of carbon for the synthesis of glucose. Oxygen, glucose, and soil are not necessary reactants for photosynthesis.