Biological Molecules (First Year Chapter 2)

CO2, or carbon dioxide, is not an organic compound because it does not contain carbon-hydrogen bonds. Organic compounds are defined as compounds that contain carbon and hydrogen atoms bonded together. Carbohydrates, proteins, and lipids are all examples of organic compounds because they contain carbon-hydrogen bonds. CO2 consists of one carbon atom bonded to two oxygen atoms, and therefore does not meet the criteria to be classified as an organic compound.

Carbohydrates in the cell combine with protein to form a compound known as glycoprotein. Glycoproteins are important molecules found on the cell surface and play various roles such as cell recognition, cell signaling, and immune response. They consist of a protein component to which carbohydrates are attached through covalent bonds. This combination of carbohydrates and proteins allows glycoproteins to have diverse functions and participate in crucial biological processes.

Glycogen, a form of glucose storage, is primarily stored in the liver and muscles. The liver stores glycogen to regulate blood sugar levels and release glucose when needed. The muscles store glycogen to provide a local energy source during physical activity. Therefore, option a) Liver and muscle is the correct answer.

Large organic compounds such as cellulose, fats, and proteins are generally insoluble in water due to their hydrophobic nature. These compounds have nonpolar regions that repel water molecules, making it difficult for them to dissolve in water. Additionally, their size and complex structure make it harder for them to form stable interactions with water molecules. Therefore, they tend to remain in their solid or aggregated state when in contact with water.

The general formula of a monosaccharide is (CH2O)n, where n represents the number of carbon atoms present in the molecule. This formula indicates that monosaccharides are composed of carbon, hydrogen, and oxygen atoms, with the ratio of hydrogen to oxygen atoms being 2:1, similar to the ratio found in water (H2O). The presence of the carbon backbone and the arrangement of the hydrogen and oxygen atoms in this formula are characteristic of monosaccharides, which are the simplest form of carbohydrates.

The most common monosaccharides are hexoses and pentoses. Monosaccharides are the simplest form of carbohydrates and are composed of a single sugar molecule. Hexoses have six carbon atoms, while pentoses have five carbon atoms. Examples of hexoses include glucose and fructose, which are important energy sources for the body. Pentoses include ribose and deoxyribose, which are components of nucleic acids such as DNA and RNA. These two groups of monosaccharides are the most abundant and biologically significant in living organisms.

Carbohydrates are organic compounds that consist of carbon, hydrogen, and oxygen atoms. They are classified as polyhydroxy compounds because they contain multiple hydroxyl (OH) groups. The correct answer, option a) Aldehydes and ketones, is accurate because carbohydrates are derived from aldehydes and ketones through a process called condensation. In this process, multiple aldehyde or ketone molecules react with each other, forming glycosidic bonds and resulting in the formation of complex carbohydrates. Therefore, option a) correctly identifies the chemical composition of carbohydrates.

The correct answer is a) Glycosidic bond. A glycosidic bond is a type of covalent bond that forms between two monosaccharides, which are simple sugars. This bond is formed through a condensation reaction, where a hydroxyl group from one monosaccharide combines with a hydrogen atom from another monosaccharide, resulting in the formation of a glycosidic bond and the release of a water molecule. Glycosidic bonds are important for the formation of larger carbohydrates such as disaccharides and polysaccharides.

The general formula of carbohydrates is Cn(H2O)n, where n represents the number of carbon atoms in the molecule. This formula indicates that carbohydrates are composed of carbon, hydrogen, and oxygen atoms in a ratio that is usually close to 1:2:1. This formula allows for the variability in the size and structure of different carbohydrates, as it does not specify a fixed number of carbon atoms or a specific arrangement of atoms. Therefore, option c) Cn(H2O)n is the correct answer.

In a monosaccharide, all carbons except one have a hydroxyl group. This means that all carbons, except for one, are bonded to a hydroxyl group (-OH). The correct answer, "a) One carbon," indicates that there is only one carbon in a monosaccharide that does not have a hydroxyl group.

Ribose is a monosaccharide that forms a five-cornered ring structure. It is a pentose sugar, meaning it has five carbon atoms. In its ring form, ribose has four carbon atoms and one oxygen atom, arranged in a pentagon shape. This ring structure is important in the formation of nucleotides, which are the building blocks of RNA. Ribose is commonly found in RNA molecules, where it plays a crucial role in genetic information transfer and protein synthesis.

Monosaccharides are simple sugars that are sweet and soluble in water. They can be hydrolyzed into simpler forms of sugar. Therefore, the set of qualities related to monosaccharides is "Sweet, soluble in water, can be hydrolyzed into simple sugar."

Sucrose is the most familiar disaccharide because it is commonly known as table sugar. It is made up of glucose and fructose molecules bonded together. Sucrose is widely used as a sweetener in various food and beverages, making it a familiar disaccharide to most people. Maltose is another disaccharide made up of two glucose molecules, while lactose is a disaccharide found in milk consisting of glucose and galactose molecules. Therefore, the correct answer is b) Sucrose.

Polysaccharides are large carbohydrates made up of many sugar molecules bonded together. Hydrolysis is a chemical reaction that breaks these bonds by adding water molecules. When polysaccharides undergo hydrolysis, they are broken down into their individual sugar units. In this case, the correct answer is b) Glucose molecules, as hydrolysis of polysaccharides will yield glucose molecules.

Plants are the primary source of carbohydrates because they undergo photosynthesis, a process in which they convert sunlight, water, and carbon dioxide into glucose (a type of carbohydrate) and oxygen. Animals, on the other hand, obtain carbohydrates by consuming plants or other animals that have consumed plants. Therefore, while both plants and animals can contain carbohydrates, plants are the primary source as they are able to produce carbohydrates through photosynthesis.

The correct answer is d) All of the above. Starch is a complex carbohydrate that serves as a major energy storage molecule in plants. It is found in abundance in grains such as rice, wheat, and corn, which are commonly consumed as staple foods. Seeds, such as beans and lentils, also contain starch as a source of energy for the developing plant embryo. Additionally, fruits like bananas and tubers like potatoes also contain starch, which provides energy for the plant during growth and development. Therefore, all of these sources contribute to the overall availability of starch.

Oligosaccharides are carbohydrates that are relatively less sweet in taste and less soluble in water. Monosaccharides are single sugar molecules and are typically sweet in taste. Polysaccharides are complex carbohydrates made up of many sugar molecules and can be sweet or tasteless. Since oligosaccharides are composed of a few sugar molecules, they have a less pronounced sweet taste and are less soluble in water compared to monosaccharides. Therefore, the correct answer is c) Oligosaccharides.

Cellulase is the correct answer because it is the enzyme responsible for the digestion of cellulose. Cellulose is a complex carbohydrate found in plant cell walls, and it cannot be broken down by the human digestive system. However, certain microorganisms and animals, such as termites and cows, produce cellulase to break down cellulose into simpler sugars that can be digested and utilized for energy. Cellulase breaks the bonds between the glucose molecules in cellulose, allowing for its digestion and absorption.

The correct answer is b) Harnivores. Harnivores, also known as herbivores, are organisms that primarily consume plant material as their main source of nutrition. They have specialized digestive systems that are capable of breaking down and extracting nutrients from cellulose, which is the main component of plant cell walls. Carnivores primarily consume meat, protozoans are single-celled organisms that can feed on a variety of food sources, and vegetarians are humans who choose not to consume meat but can still struggle to digest cellulose efficiently. Therefore, harnivores are the class of organisms that can digest cellulose effectively.

The correct answer is a)Italic word. Carbohydrates, also known as saccharides, are derived from the Italic word.