1.
What is osmosis?
Correct Answer
B. The movement of molecules such as water through a semi-permeable membrane from an area of higher concentration to an area of lower concentration
Explanation
The correct answer is "The movement of molecules from an area of higher concentration to an area of lower concentration" because diffusion is specifically trying to equalize the percentage, or concentration, of all substances in two areas. Therefore, molecules move from a higher concentration to a lower concentration to try to balance the two out.
2.
Which of these molecules can NOT pass through a membrane to enter a cell?
Correct Answer
D. Starch
Explanation
As we observed in the Diffusion Through a Membrane lab, starch cannot pass through a semi-permeable membrane. We know this because the solution surrounding the "cell" we constructed remained amber, instead of turning purple. Starch is too large a molecule to pass through the membrane of a cell.
3.
Which of these does require energy?
Correct Answer
A. Active Transport
Explanation
Active transport is the movement of molecules from an area of lower concentration to an area of higher concentration. Because this defies the law of diffusion, it takes the proteins on the membrane energy to transport molecules across.
4.
When a molecule enters a cell via the proteins on its membrane but the process doesn't use any ATP, it has undergone:
Correct Answer
D. Facilitated diffusion
Explanation
Facilitated diffusion is the transfer of molecules from a higher concentration to lower concentration (passive transport) through the proteins on the membrane. Molecules that enter through the proteins are often too large or ionic/polar to enter straight through the phospholipid bi-layer. These are also the only molecules which can undergo active transport.
5.
A cell placed in a hypotonic solution will....
Correct Answer
A. Swell due to taking in water
Explanation
When a cell is placed in a hypotonic solution, the concentration of solutes inside the cell is higher than that of the surrounding solution. As a result, water molecules move into the cell through osmosis, causing the cell to swell. This is because water moves from an area of lower solute concentration (the hypotonic solution) to an area of higher solute concentration (the cell). Therefore, the correct answer is "swell due to taking in water."
6.
Osmosis occurs in
Correct Answer
A. All cells; they all have cell membranes
Explanation
Osmosis is the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. Since all cells have cell membranes, they are all capable of undergoing osmosis. The cell membrane acts as a barrier that allows the passage of water molecules while regulating the movement of solutes in and out of the cell. Therefore, osmosis can occur in all cells because they all possess cell membranes.
7.
The atom is made of 3 subatomic particles. The subatomic particle found in the nucleus with a positive charge is the ___________.
Correct Answer
C. Proton
Explanation
The atom is made up of three subatomic particles: electrons, neutrons, and protons. The subatomic particle found in the nucleus with a positive charge is the proton. Electrons have a negative charge and are found outside the nucleus, while neutrons have no charge and are also found in the nucleus. Protons are positively charged and are crucial in determining the element and properties of an atom.
8.
The __________ is the smallest unit of matter.
Correct Answer
B. Atom
Explanation
An atom is the smallest unit of matter that retains the properties of an element. It consists of a nucleus, which contains protons and neutrons, and electrons that orbit the nucleus. Elements are made up of atoms, and atoms combine to form molecules. Electrons are subatomic particles found within atoms, but they are not the smallest unit of matter. Therefore, the correct answer is atom.
9.
An _______ bond is a bond in which electrons are transferred between a metal and nonmetal.
Correct Answer
B. Ionic
Explanation
An ionic bond is a bond in which electrons are transferred between a metal and nonmetal. In an ionic bond, one atom donates electrons to another atom, resulting in the formation of positively charged cations and negatively charged anions. This transfer of electrons creates a strong electrostatic attraction between the oppositely charged ions, forming a stable bond.
10.
An acid has a pH below ______.
Correct Answer
A. 7
Explanation
An acid has a pH below 7 because pH is a measure of the acidity or alkalinity of a solution. A pH value below 7 indicates that the solution is acidic, while a pH value above 7 indicates that the solution is alkaline or basic. Therefore, any value below 7 is considered acidic, making 7 the correct answer.
11.
A base has a ph above _____.
Correct Answer
C. 7
Explanation
A base has a pH above 7 because pH is a measure of the concentration of hydrogen ions in a solution. A pH value below 7 indicates an acidic solution, while a pH value above 7 indicates a basic solution. Therefore, a base with a pH above 7 is alkaline.
12.
Water is made of 1 oxygen molecule and _____ hydrogen atoms.
Correct Answer
B. 2
Explanation
Water is made of 1 oxygen molecule and 2 hydrogen atoms. This is because the chemical formula for water is H2O, which means that each water molecule consists of 2 hydrogen atoms bonded to 1 oxygen atom.
13.
The water molecule is _________, because there is an uneven distribution of electron within the molecule.
Correct Answer
C. Polar
Explanation
The water molecule is polar because there is an uneven distribution of electrons within the molecule. This is due to the oxygen atom being more electronegative than the hydrogen atoms, causing the oxygen to pull the shared electrons closer to itself. As a result, the oxygen atom has a partial negative charge, while the hydrogen atoms have partial positive charges. This polarity gives water its unique properties, such as its ability to form hydrogen bonds and its high surface tension.
14.
A group of atoms bound together
Correct Answer
B. Molecule
Explanation
A molecule is a group of atoms that are bound together by chemical bonds. It is the smallest unit of a compound that retains the chemical properties of that compound. In other words, a molecule is formed when two or more atoms come together and are held together by covalent bonds. This allows them to function as a single unit and exhibit unique chemical properties. Therefore, a molecule is the correct answer as it accurately describes a group of atoms bound together.
15.
All of these are major organic compounds except
Correct Answer
D. Acids
Explanation
Acids are not considered major organic compounds. While carbohydrates, lipids, and proteins are all major organic compounds found in living organisms, acids are not classified as major organic compounds. Acids are a class of compounds that are characterized by their ability to donate protons or accept electrons. They are not typically considered as major components of living organisms, unlike carbohydrates, lipids, and proteins which play essential roles in various biological processes.
16.
All the substances listed are Inorganic except
Correct Answer
D. Proteins
Explanation
Acids, bases, and salts are all inorganic substances because they do not contain carbon. Proteins, on the other hand, are organic substances because they are composed of carbon, hydrogen, oxygen, and nitrogen atoms. Therefore, proteins are the only substance listed that is not inorganic.
17.
Fats and oils are examples of
Correct Answer
B. Lipids
Explanation
Fats and oils are examples of lipids. Lipids are a group of organic compounds that are insoluble in water but soluble in organic solvents. They are an essential part of the diet and play important roles in the body, such as providing energy, insulating and protecting organs, and serving as a structural component of cell membranes. Fats and oils are types of lipids that are commonly found in food and are a concentrated source of energy. Therefore, the correct answer is lipids.
18.
Large Molecules made up of amino acids held together in long folded chains by peptide bonds
Correct Answer
A. Proteins
Explanation
Proteins are large molecules composed of amino acids that are linked together by peptide bonds. These amino acids form long, folded chains, which give proteins their unique structure and function. Proteins play a crucial role in various biological processes, including cell signaling, enzymatic reactions, and structural support. They are essential for the growth, repair, and maintenance of tissues in the body. Therefore, proteins are the correct answer in this case.
19.
Neutron's are
Correct Answer
B. Noncharged particles in nucleus
Explanation
Neutrons are noncharged particles in the nucleus. Unlike protons, which have a positive charge, neutrons have no charge. They are essential components of an atom along with protons, and their main role is to add mass to the nucleus without affecting the overall charge. Neutrons help stabilize the nucleus and are crucial for maintaining the stability of an atom.
20.
Number of protons and neutrons in the nucleus
Correct Answer
D. Atomic mass
Explanation
The atomic mass of an element is the sum of the number of protons and neutrons in the nucleus of an atom. It is a measure of the mass of an atom and is usually expressed in atomic mass units (amu). The number of protons determines the element's identity, while the number of neutrons can vary, resulting in different isotopes of the same element. Therefore, the atomic mass provides information about the composition of the nucleus and helps in identifying and distinguishing different elements.
21.
Substances whose molecules have more than one kind of atom
Correct Answer
B. Compound
Explanation
A compound is a substance that is composed of two or more different elements chemically bonded together. In this case, the question is asking for substances whose molecules have more than one kind of atom, which perfectly describes a compound. Isotopes refer to atoms of the same element that have different numbers of neutrons, while chemical elements and cations are not specific to substances with more than one kind of atom. Therefore, the correct answer is compound.
22.
Which as a positive charged particle in the nucleus
Correct Answer
B. Proton
Explanation
Protons are positively charged particles found in the nucleus of an atom. They have a mass of approximately 1 atomic mass unit and carry a charge of +1. Electrons, on the other hand, are negatively charged particles that orbit around the nucleus. Neutrons are neutral particles with no charge. Matter refers to anything that has mass and occupies space. Therefore, the correct answer is proton, as it is the only option that fits the description of a positive charged particle in the nucleus.
23.
The number of protons in an atom of an element
Correct Answer
D. Atomic number
Explanation
The atomic number of an element represents the number of protons in an atom of that element. Protons are positively charged particles found in the nucleus of an atom. Each element has a unique atomic number, which determines its position on the periodic table. The atomic number is crucial in identifying and classifying elements, as it determines their chemical properties and the number of electrons surrounding the nucleus. Therefore, the correct answer is atomic number.
24.
A solution with excess hydrogen ion (H+) concentration:
Correct Answer
C. Acid
Explanation
A solution with excess hydrogen ion (H+) concentration is considered an acid. Acids are substances that release hydrogen ions when dissolved in water, increasing the concentration of H+ ions. This excess of H+ ions gives the solution its acidic properties, such as sour taste, ability to react with metals, and ability to turn blue litmus paper red. Therefore, the given answer "Acid" accurately describes a solution with excess hydrogen ion concentration.
25.
These molecules primarily serve to provide the body with energy:
Correct Answer
A. Carbohydrates
Explanation
Carbohydrates primarily serve to provide the body with energy. When consumed, carbohydrates are broken down into glucose, which is then used as a fuel source by the body's cells. Glucose is particularly important for the brain and muscles, as they rely heavily on this energy source. Carbohydrates can be found in foods such as grains, fruits, vegetables, and dairy products.
26.
These molecules serve as an energy store and makeup the majority of a cell membrane:
Correct Answer
C. Lipids
Explanation
Lipids serve as an energy store and make up the majority of a cell membrane. They are hydrophobic molecules that include fats, oils, and cholesterol. Lipids are an essential component of cell membranes, providing structure and stability. They also function as a long-term energy storage molecule, as they can be broken down to release energy when needed. Additionally, lipids play a role in insulation and protection of organs. Therefore, lipids are the correct answer as they fulfill both the energy storage and cell membrane composition functions.
27.
These molecules make up enzymes:
Correct Answer
B. Proteins
Explanation
Proteins are composed of amino acids and are the primary molecules that make up enzymes. Enzymes are biological catalysts that speed up chemical reactions in the body. They play a crucial role in various physiological processes by facilitating the conversion of substrates into products. Proteins have a specific three-dimensional structure that allows them to bind to specific substrates and catalyze reactions. Therefore, proteins are the correct answer as they are directly involved in the formation and functioning of enzymes.
28.
These molecules are made of numerous amino acids:
Correct Answer
B. Proteins
Explanation
Proteins are indeed made of numerous amino acids. Amino acids are the building blocks of proteins, and they are linked together through peptide bonds to form long chains. These chains then fold and interact with each other to create the unique three-dimensional structure of proteins. Proteins have a wide range of functions in the body, including serving as enzymes, hormones, antibodies, and structural components.
29.
These molecules include starch and cellulose:
Correct Answer
A. Carbohydrates
Explanation
Carbohydrates are a type of organic compound that includes molecules such as starch and cellulose. Starch is a polysaccharide that serves as a storage form of energy in plants, while cellulose is a structural polysaccharide found in the cell walls of plants. Both starch and cellulose are composed of glucose monomers, which are linked together in different ways. Carbohydrates are an essential macronutrient and serve as a major source of energy for living organisms.
30.
This is a molecule found in the cell wall of plants
Correct Answer
C. Cellulose
Explanation
Cellulose is a molecule found in the cell wall of plants. It is a polysaccharide composed of glucose units linked together. Cellulose provides structural support to plant cells and is the most abundant organic compound on Earth. It forms long, rigid chains that are interconnected, creating a strong and stable network. This allows plants to maintain their shape and withstand mechanical stress. Unlike glucose and starch, cellulose cannot be digested by most organisms due to its complex structure and the lack of appropriate enzymes. Lipids and enzymes are not specific to the cell wall of plants, making cellulose the correct answer.
31.
This is a molecule is a catalyst:
Correct Answer
E. Enzymes
Explanation
Enzymes are proteins that act as catalysts in biological reactions. They speed up chemical reactions by lowering the activation energy required for the reaction to occur. Unlike other molecules listed, enzymes are not consumed or altered during the reaction, making them reusable. Glucose, starch, cellulose, and lipids are not catalysts but rather types of carbohydrates and lipids that serve different functions in the body. Enzymes, on the other hand, play a crucial role in various metabolic processes by facilitating chemical reactions.
32.
This is a molecule is an immediate source of energy for all living cells:
Correct Answer
A. Glucose
Explanation
Glucose is the correct answer because it is a simple sugar that can be easily broken down through cellular respiration to release energy in the form of ATP. Glucose is the primary source of energy for cells and is used in various metabolic processes to fuel cellular activities. Starch and cellulose are complex carbohydrates that require further digestion before they can be used as an energy source. Lipids, although they can be broken down to release energy, are not as readily available as glucose. Enzymes, on the other hand, are proteins that facilitate biochemical reactions but do not directly provide energy.
33.
This molecules is made of many, many sugars bound together:
Correct Answer
B. Starch
Explanation
Starch is a complex carbohydrate made up of many glucose molecules bound together. It is a polysaccharide that serves as a storage form of energy in plants. Starch is composed of amylose and amylopectin, which are long chains of glucose units. It is commonly found in foods such as potatoes, rice, and bread. The structure of starch allows it to be broken down into glucose molecules during digestion, providing a source of energy for the body.
34.
2 H2 + O2 -> 2 H2OIn the above reaction, how many atoms of reactants are depicted?
Correct Answer
C. 6
Explanation
In the given reaction, there are 2 molecules of H2 and 1 molecule of O2 as reactants. Each H2 molecule contains 2 atoms of hydrogen, so there are a total of 4 atoms of hydrogen. The O2 molecule contains 2 atoms of oxygen. Therefore, the total number of atoms of reactants depicted in the reaction is 4 + 2 = 6.
35.
2 H2 + O2 -> 2 H2OIn the above reaction, what is/are the products?
Correct Answer
C. Water
Explanation
The given reaction represents the combination of two hydrogen molecules (H2) with one oxygen molecule (O2) to form two water molecules (H2O). Therefore, the product of the reaction is water.
36.
If a lipid is a solid at room temperature, you would predict
Correct Answer
B. The lipid is saturated
Explanation
If a lipid is a solid at room temperature, it indicates that the lipid is saturated. Saturated lipids have only single bonds between carbon atoms, which allows them to pack tightly together and form a solid structure. Unsaturated lipids, on the other hand, have at least one double bond between carbon atoms, which introduces a kink in the molecule and prevents tight packing, resulting in a liquid state at room temperature. Therefore, based on the given information, it can be predicted that the lipid is saturated.
37.
Carbohydrates are mainly used in our bodies:
Correct Answer
C. As fuel
Explanation
Carbohydrates are primarily used in our bodies as fuel. They are broken down into glucose, which is then used by our cells to produce energy through a process called cellular respiration. This energy is essential for various bodily functions, such as muscle contraction, nerve signaling, and overall metabolism. While carbohydrates can also play a role in structural molecules, membrane construction, and building genetic material, their primary function is to provide energy for our body's activities.
38.
Proteins are polymers of __________.
Correct Answer
D. Amino acids
Explanation
Proteins are composed of amino acids, which are the building blocks of proteins. Amino acids are organic compounds that contain an amino group (-NH2) and a carboxyl group (-COOH). These amino acids are linked together through peptide bonds to form long chains, known as polypeptides, which then fold into complex three-dimensional structures to create proteins. Therefore, the correct answer is amino acids.
39.
This molecule is made of proteins:
Correct Answer
F. Enzyme
Explanation
Enzymes are biological molecules made up of proteins. They act as catalysts in various biochemical reactions, speeding up the rate of these reactions without being consumed in the process. Enzymes have specific shapes that allow them to bind to specific substrates, facilitating the conversion of these substrates into products. They play a crucial role in metabolism and are essential for many physiological processes in living organisms. Therefore, the molecule "Enzyme" is correctly identified as being made up of proteins.
40.
This molecule is the main energy for cells:
Correct Answer
A. Glucose
Explanation
Glucose is the main energy source for cells. It is a simple sugar that is broken down during cellular respiration to produce ATP, the energy currency of cells. Glucose can be easily metabolized by cells to generate energy, making it an essential molecule for cellular processes.
41.
This molecule consists of many sugars connected via chemical bonds:
Correct Answer
C. Starch
Explanation
Starch is a complex carbohydrate made up of many glucose molecules connected through chemical bonds. It is a polysaccharide and serves as a storage form of energy in plants. Starch is commonly found in foods such as potatoes, rice, and bread. It can be broken down by enzymes in the body to release glucose for energy. Unlike lipids, fats, and enzymes, which have different structures and functions, starch specifically refers to the arrangement of glucose molecules in a chain-like structure.
42.
This molecule is a long-term store of energy in plants:
Correct Answer
C. Starch
Explanation
Starch is a polysaccharide that serves as a long-term energy storage molecule in plants. It is made up of glucose units and is stored in plant cells, particularly in structures called amyloplasts. Starch is an important source of energy for plants, as it can be broken down into glucose when needed for growth, development, or metabolic processes. It is commonly found in plant-based foods like potatoes, rice, and wheat, and is also used as a thickening agent in various food products.
43.
This molecule is common in the cell wall of plants:
Correct Answer
G. Cellulose
Explanation
Cellulose is a molecule that is commonly found in the cell wall of plants. It is a polysaccharide made up of glucose units linked together. Cellulose provides structural support to plant cells and gives rigidity to the cell wall. It is a major component of plant fibers and is indigestible by humans due to the lack of enzymes required to break down its complex structure. Cellulose is essential for the integrity and strength of plant cell walls and plays a crucial role in plant growth and development.
44.
Which of the following elements is NOT found in all organic compounds?
Correct Answer
C. Chlorine
Explanation
Chlorine is not found in all organic compounds because organic compounds are primarily composed of carbon and hydrogen atoms, with the occasional presence of oxygen. Chlorine is not a common element in organic compounds and is typically found in inorganic compounds or as a substituent in certain organic compounds. Therefore, chlorine is the element that is not found in all organic compounds.
45.
Which of the following is a polymer?
Correct Answer
C. Starch
Explanation
Starch is a polymer because it is composed of repeating units of glucose molecules. It is a complex carbohydrate made up of amylose and amylopectin molecules, which are long chains of glucose units bonded together. This polymer structure gives starch its characteristic properties, such as its ability to be broken down into glucose for energy storage in plants and its ability to form a gel-like substance when heated. In contrast, glucose, amino acid, and sugar are not polymers but rather monomers or simple molecules.
46.
Enzymes interact with substrates (such as milk) at their...
Correct Answer
B. Active site
Explanation
Enzymes interact with substrates at their active site. The active site is a specific region on the enzyme where the substrate binds and undergoes a chemical reaction. This site has a unique shape and chemical properties that allow it to bind to the substrate and facilitate the conversion of the substrate into a product. The active site plays a crucial role in enzyme catalysis, as it provides a favorable environment for the reaction to occur and helps to lower the activation energy needed for the reaction to proceed.
47.
Describe this graph:
Correct Answer
B. Inversely Proportional
Explanation
The graph is inversely proportional because as one variable increases, the other variable decreases. This can be seen by the negative slope of the graph. In an inversely proportional relationship, the product of the two variables remains constant. As one variable increases, the other variable decreases in order to keep the product constant.
48.
How many molecules of product are depicted in the above equation?
Correct Answer
C. 13
Explanation
The above equation shows a chemical reaction. In order to determine the number of molecules of product, we need to examine the coefficients in front of the reactants and products. In this case, there is a coefficient of 13 in front of the product. This means that 13 molecules of the product are depicted in the equation.
49.
How many atoms of reactants in the above reaction?
Correct Answer
D. 54
50.
The Greenhouse Effect is best summarized by which of the following options?
Correct Answer
B. Increased carbon dioxide levels in Earths atmospHere increase global temperatures.
Explanation
The Greenhouse Effect refers to the process by which certain gases in the Earth's atmosphere trap heat from the sun, leading to an increase in global temperatures. Increased carbon dioxide levels in Earth's atmosphere contribute to this effect by trapping more heat and causing a rise in temperatures. This option accurately summarizes the relationship between increased carbon dioxide levels and global temperatures in the context of the Greenhouse Effect.