AP Chemistry Notes Review #2

Anthony is experiencing symptoms of dehydration and electrolyte imbalance due to running at full speed in humid weather without ingesting any fluids. Electrolytes, such as sodium, potassium, and magnesium, are essential for proper muscle function and hydration. When Anthony sweats excessively in the heat, he loses electrolytes through his sweat. The lack of electrolytes can lead to dizziness, weakness, and a feeling of passing out. Therefore, his likely ailment is an electrolyte imbalance.

Lipids do not readily dissolve in water because they are hydrophobic, meaning they repel water. Lipids are nonpolar molecules, while water is a polar molecule. The polar nature of water causes it to form hydrogen bonds with other water molecules, creating a network of intermolecular attractions. Lipids, on the other hand, have nonpolar hydrocarbon chains that are unable to form hydrogen bonds with water. As a result, lipids tend to aggregate together and separate from water, making them insoluble in water.

Steroids are a class of organic compounds that have a characteristic ring structure. This ring structure is composed of three cyclohexane rings and one cyclopentane ring fused together. This arrangement of rings gives steroids their unique shape and chemical properties. Therefore, the statement that steroids have ring structures is true.

Sodium salts are necessary for nerve impulses because they help in the transmission of electrical signals along the nerves. Sodium ions play a crucial role in depolarizing the nerve cell membrane, allowing the nerve impulse to be conducted. Without sodium salts, the nerve impulses would not be able to travel efficiently, leading to disruptions in the nervous system's functioning. Therefore, it is true that sodium salts are necessary for nerve impulses.

Lipids, like carbohydrates, contain the same three elements: carbon, hydrogen, and oxygen. This is because lipids are organic compounds, just like carbohydrates, and these three elements are the building blocks of organic molecules. Therefore, it is true that lipids contain the same three elements as carbohydrates.

Cholesterol serves as a precursor for the synthesis of various steroids in the body. It is converted into hormones such as cortisol, aldosterone, and sex hormones like estrogen and testosterone. These steroids play crucial roles in regulating various physiological processes. Therefore, it is correct to say that cholesterol is a building block for many other steroids.

This statement is false. Trans fats are actually considered to be the unhealthiest type of fat. They are artificially created through a process called hydrogenation, which turns liquid oils into solid fats. Trans fats have been linked to an increased risk of heart disease, high cholesterol levels, and inflammation in the body. It is recommended to limit or avoid consumption of trans fats for better health.

This statement is true because amino acids are composed of a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and an R group. The R group, also known as the side chain, is what distinguishes one amino acid from another. It can be a variety of different structures, such as a single atom or a complex molecule. Therefore, the R group is the only part of the amino acid that varies, while the rest of the structure remains the same.

Glucose is oxidized to add energy to ADP to form ATP. During cellular respiration, glucose is broken down through a series of chemical reactions, releasing energy that is used to convert ADP (adenosine diphosphate) into ATP (adenosine triphosphate). This process, known as oxidative phosphorylation, occurs in the mitochondria of cells and is the main source of energy for cellular activities.

The explanation for the given correct answer is that tertiary structure refers to the overall 3D shape of a protein, which is crucial for its function. Globular proteins are known for their compact, spherical shape, which is a characteristic of tertiary structure. On the other hand, fibrous proteins have a more elongated and repetitive structure, lacking the complex folding seen in tertiary structure. Therefore, it is true that globular proteins tend to have a tertiary structure, while fibrous proteins do not.

High temperatures and extreme pH levels can denature enzymes by disrupting their secondary, tertiary, or quaternary structure. This denaturation leads to a loss of enzyme functionality, rendering them non-functional. Therefore, the statement "Very high temperatures or the 'wrong' pH can destroy the secondary, tertiary, or quaternary structure of enzymes, making them non-functional" is true.

Muscle cells require ATP (adenosine triphosphate) for energy because ATP is the primary source of energy for cellular processes. When muscles contract, ATP is broken down into ADP (adenosine diphosphate) and inorganic phosphate, releasing energy that powers muscle contraction. This energy is necessary for muscle cells to perform their functions, such as movement and maintaining muscle tone. Therefore, it is true that muscle cells require ATP for energy.

The statement is incorrect. Neutral acids and biglyceride are not interchangeable terms. Neutral acids refer to acids that are neither acidic nor basic, while biglyceride refers to a type of lipid molecule composed of three fatty acid chains bonded to a glycerol molecule. Therefore, the given statement is false.

Triglycerides are indeed composed of a glycerol and 3 fatty acid chains joined together by dehydration synthesis. This process involves the removal of a water molecule to form an ester bond between the glycerol and each fatty acid chain. This structure is what allows triglycerides to serve as a major form of energy storage in the body and play a role in various physiological processes. Therefore, the statement "Triglycerides are composed of a glycerol and 3 fatty acids chains joined together by dehydration synthesis" is true.

Lipids, such as adipose tissue, are found around organs in the body. These lipids serve as a cushioning and protective layer for the organs, helping to absorb shocks and prevent damage. This is why the statement is true.

Fibrous proteins have a long, extended shape and are composed of repeating patterns of amino acids, such as collagen and keratin. This structural arrangement allows for strong intermolecular forces and extensive cross-linking, making fibrous proteins highly stable. On the other hand, globular proteins have a compact, spherical shape and are involved in various functions, such as enzymes and antibodies. While globular proteins can also be stable, their structure is more flexible and prone to denaturation under certain conditions compared to fibrous proteins. Therefore, it can be concluded that fibrous proteins are generally more stable than globular proteins.

The correct answer is "at the bottom of this picture" because in the given question, it is mentioned that the polymer is the molecule at the bottom of the picture.

Triglycerides can be saturated or unsaturated because they are composed of fatty acids. Saturated triglycerides have fatty acids with only single bonds, while unsaturated triglycerides have fatty acids with one or more double bonds. This difference in bonding affects the structure and properties of the triglyceride molecule.

Lipids are a type of biomolecule that serve as a long-term energy storage in the body. They are broken down during metabolism to release energy when needed. This storage function of lipids is particularly important in organisms that need to survive periods of food scarcity or during prolonged physical activity. Therefore, the statement that lipids store energy is true.

Phospholipids are actually found in both cell walls and cell membranes. They form the basic structure of these membranes, creating a lipid bilayer that acts as a barrier and controls the movement of substances in and out of the cell. Therefore, the statement that phospholipids are found in cell walls but not cell membranes is incorrect.

Cholesterol is not a part of either Vitamin C or Vitamin D. Cholesterol is a type of fat that is found in our bodies and certain foods. It is not classified as a vitamin. Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that is important for the growth, development, and repair of body tissues. Vitamin D, on the other hand, is a fat-soluble vitamin that helps the body absorb calcium and is important for bone health. Therefore, the statement that cholesterol is a part of Vitamin C but not D is incorrect.

A globular protein is not the same as a structural protein. Globular proteins are typically compact and rounded in shape, and they are involved in various functions such as enzymatic activity, transport, and signaling. On the other hand, structural proteins provide support and stability to cells and tissues, such as collagen in connective tissues and keratin in hair and nails. While some proteins can have both globular and structural regions, the terms "globular protein" and "structural protein" refer to different characteristics and functions.

NaCl is not an organic compound because it does not contain carbon. Organic compounds are defined as compounds that contain carbon atoms bonded to hydrogen atoms, along with other elements such as oxygen, nitrogen, and sulfur. C2H4O2 and C4H10 both contain carbon atoms, making them organic compounds. NaCl, on the other hand, is composed of sodium (Na) and chlorine (Cl) atoms, with no carbon present, making it an inorganic compound.

Trans fats are indeed produced by the process of hydrogenation, which involves adding hydrogen to unsaturated fats. This process increases the shelf life and stability of fats, but also creates trans fats, which are known to be unhealthy and increase the risk of heart disease. Therefore, the statement that trans fats are produced by hydrogenating unsaturated fats is true.

Cholesterol is a substance that is produced by the body and is also found in certain foods. While the body does produce cholesterol, it is also obtained through the diet. Therefore, the statement that "Cholesterol must be ingested; your body cannot produce its own" is false.

An electrolyte conducts electrical impulses because it contains ions that are capable of carrying electric charge. When dissolved in water, these ions can move freely and allow for the flow of electric current. This property makes electrolytes useful in various physiological processes, such as nerve conduction and muscle contraction. In situations of dehydration, electrolytes can be substituted for water to help replenish the body's electrolyte balance and prevent further imbalances that can occur with water alone.

Collagen and keratin are indeed examples of structural proteins in the human body. Collagen provides strength and support to various tissues such as skin, bones, tendons, and ligaments. Keratin, on the other hand, is a protein found in hair, nails, and the outer layer of the skin, providing structural integrity and protection. These proteins play crucial roles in maintaining the structure and function of different body parts.

Dehydration synthesis is a chemical reaction that involves the removal of water molecules to join monomers and form polymers. This process is also known as condensation reaction. By removing water, the monomers are able to bond together and form larger molecules, which are called polymers. Therefore, the correct answer is "One way to make polymers; to join monomers, dehydration synthesis removes water."

Glycogen is a molecule that is present in the liver and functions as an energy storage molecule. When the body needs to raise blood sugar levels, glycogen is hydrolyzed, meaning it is broken down into glucose molecules. Glucose can then be released into the bloodstream to provide a quick source of energy. Therefore, glycogen is the correct answer as it fits all the given criteria.

Starch is a complex carbohydrate found in many foods, such as potatoes, rice, and bread. When consumed, it is broken down into glucose, which is then used by the body as a source of energy. This process provides a steady release of energy over time, making starch an important component of a balanced diet. Therefore, it is correct to say that people can use starch as a source of energy.

Cellulose is a complex carbohydrate found in the cell walls of plants. While humans lack the necessary enzymes to break down cellulose, some animals like cows and termites have specialized digestive systems that can process cellulose. However, humans cannot use cellulose as a direct source of energy because our bodies cannot digest it. Therefore, the statement that people can use cellulose as a source of energy is false.

Cellulose, which is a type of fiber, is good to eat because it helps food pass more easily through our digestive tracts. It does this by irritating or slightly scraping the lining of the digestive tract, which stimulates it to produce more mucus. This increased mucus production helps in the smooth movement of food through the digestive system. Additionally, cellulose takes a long time to break down, providing a constant supply of energy rather than a quick burst of sugar. It also tastes like sugar, fooling our bodies into thinking we ate sugar and increasing metabolism, but it does not provide any calories, making it helpful for weight management.

Saturated fats are indeed saturated with hydrogen atoms, which means they do not have any double or triple bonds. This makes them more stable and solid at room temperature. In contrast, unsaturated fats have double or triple bonds, which leads to a kinked molecular structure and a liquid state at room temperature. Therefore, the given answer "True" is correct.

All amino acids contain an amine group and an acid group. This is because amino acids are organic compounds that have both an amino group (-NH2) and a carboxyl group (-COOH) attached to a central carbon atom. The amine group acts as a base, while the acid group acts as an acid, allowing amino acids to act as both acids and bases. This characteristic is essential for the formation of peptide bonds and the structure and function of proteins. Therefore, it is true that all amino acids contain an amine group and an acid group.

Ionic compounds are formed by the transfer of electrons from one atom to another, resulting in the formation of positive and negative ions. In solution, the ionic compounds easily dissociate into their constituent ions due to the solvent's ability to separate the positive and negative charges. This dissociation occurs because the solvent molecules surround the ions and weaken the attractive forces between them, allowing the ions to move freely in the solution. Therefore, the given answer, "easily dissociates into ions in solution," accurately explains the behavior of ionic compounds in a solvent.

Breaking down glycogen into glucose monomers involves the addition of water molecules to break the glycosidic bonds between the glucose units. This process is known as hydrolysis. Hydrolysis is a chemical reaction that involves the breaking of a compound by the addition of water. In this case, the water molecules break the bonds between the glucose units, resulting in the release of individual glucose molecules. Therefore, hydrolysis is the correct answer for this question.

Secondary protein structure refers to the regular folding patterns that occur within a polypeptide chain, such as alpha helices and beta sheets. These folding patterns are stabilized by hydrogen bonds between the amino acids in the polypeptide backbone. Therefore, the statement that secondary protein structure occurs due to the hydrogen bonds in the polypeptide backbone is true.

Polysaccharides are large molecules made up of many sugar units bonded together. Due to their large size and complex structure, they do not readily dissolve in water. Instead, they often form gels or suspensions when mixed with water. Therefore, the statement that polysaccharides readily dissolve in water is false.

This statement is false because functional proteins, such as enzymes, are generally mobile in order to perform their specific functions within cells. On the other hand, structural proteins, such as collagen, provide support and stability to tissues and are typically less mobile. Therefore, the correct answer is false.

DNA and RNA are both polymers of nucleotide monomers. This means that they are made up of repeating units called nucleotides, which consist of a sugar molecule, a phosphate group, and a nitrogenous base. Both DNA and RNA play important roles in storing and transmitting genetic information in living organisms. They have similar structures, with the main difference being that DNA is double-stranded while RNA is usually single-stranded. Therefore, the statement "DNA and RNA are BOTH polymers of nucleotide monomers" is true.

Potassium salts are involved in nerve impulses because they play a crucial role in maintaining the electrical potential across cell membranes. Nerve impulses are electrical signals that travel along neurons, allowing for communication within the nervous system. Potassium ions are responsible for repolarizing the cell membrane after an action potential, which is essential for the propagation of nerve impulses. Therefore, the statement that potassium salts are involved in nerve impulses is true.

Carbohydrates are actually made up of carbon, hydrogen, and oxygen atoms, but not nitrogen. Therefore, the statement that carbohydrates are made of C, H, O, and N is incorrect.

The statement is true because quaternary structure refers to the arrangement and interaction of multiple polypeptide chains in a protein. Proteins with quaternary structure are composed of two or more polypeptides, which come together to form a functional protein complex. Therefore, proteins only have quaternary structures when they contain at least 2 polypeptides.

The given statement is false. The two main types of proteins are fibrous and globular, not fibrous and structural. Fibrous proteins have a long, elongated shape and provide structural support, such as collagen in connective tissues. On the other hand, globular proteins have a more compact shape and are involved in various functions, such as enzymes, antibodies, and hormones.

The given statement is false because primary protein structure refers to the linear sequence of amino acids in a protein, not the secondary structure. The secondary structure of a protein can be either a pleated sheet or a helix, but the primary structure is simply the order of amino acids.

Proteins do not provide a floating fluid for the central nervous system (CNS). While proteins play a crucial role in various functions within the body, such as building and repairing tissues, regulating hormones, and supporting the immune system, they do not directly provide a floating fluid for the CNS. The CNS is primarily composed of the brain and spinal cord, and its fluid is called cerebrospinal fluid (CSF), which is produced by specialized cells in the brain.

Cholesterol is not a type of phospholipid. While both cholesterol and phospholipids are types of lipids, they have different structures and functions. Cholesterol is a steroid lipid that is found in cell membranes and is involved in various physiological processes, such as hormone synthesis. On the other hand, phospholipids are a type of lipid that make up the cell membrane and have a phosphate group, which gives them unique properties. Therefore, the statement that cholesterol is a type of phospholipid is false.

When ATP loses a phosphate to become ADP, energy is actually released, not stored. This process is known as ATP hydrolysis, and it is an exergonic reaction that releases energy that can be used by cells for various biological processes. Therefore, the given statement is false.