Question 1

A carbohydrate that cannot be broken down into simpler carbohydrates is called a monosaccharide.

Accepted Answer

Monosaccharides are the simplest form of carbohydrates and cannot be broken down into simpler carbohydrates. Examples of monosaccharides include glucose, fructose, and galactose.

Question 2

Humans are better able to digest cellulose rather than starch because of differences in the link between the glucose units in the polysaccharide.

Accepted Answer

Humans are not able to digest cellulose because of differences in the link between the glucose units in the polysaccharide. Humans lack the necessary enzymes to break down the β-glycosidic linkages, whereas they have enzymes that can break down the α-glycosidic linkages in starch.

Question 3

The many OH groups present in carbohydrates such as glucose make them quite insoluble in water and blood.

Accepted Answer

The many OH groups present in carbohydrates such as glucose make them quite soluble in water and blood.

Question 4

If a polysaccharide is digested in the body ,it will yield many monosaccharide units.

Accepted Answer

Polysaccharides are made up of many monosaccharide units bonded together. Digestion breaks these bonds, releasing the monosaccharides for use by the body.

Question 5

Biochemistry is the study of chemical substances and processes that occur in plants,animals and microorganisms.

Accepted Answer

Biochemistry is indeed the study of chemical substances and processes that occur in living organisms such as plants, animals, and microorganisms.

Question 6

The term hydrophilic indicates a substance is repelled by water.

Accepted Answer

The term hydrophilic actually indicates a substance is attracted to water, not repelled by it.

Question 7

Fructose is an example of a hexose,a six-carbon sugar.

Accepted Answer

Fructose is indeed a hexose as it is a six-carbon sugar.

Question 8

Carbohydrates have the general formula of (CH₂O)_n.

Accepted Answer

The answer of Carbohydrates have the general formula of (CH₂O)_n....

Question 9

A disaccharide is composed of two monosaccharides connected together by a glycosidic linkage.

Accepted Answer

A disaccharide is indeed composed of two monosaccharides linked together by a glycosidic bond. Examples of disaccharides include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).

Question 10

The only structural difference between starch and cellulose is the type of linkage between glucose units.

Accepted Answer

Starch and cellulose both consist of glucose units, but the way in which the glucose units are bonded together is different. Starch has alpha linkages between glucose units, while cellulose has beta linkages. This difference in linkage type results in different physical and chemical properties between starch and cellulose.

Question 11

A pentose sugar contains more carbon atoms than does a hexose sugar.

Accepted Answer

A pentose sugar contains 5 carbon atoms, while a hexose sugar contains 6 carbon atoms.

Question 12

Glucose is an example of a monosaccharide.

Accepted Answer

Glucose is a simple sugar and a monosaccharide.

Question 13

Lipids are considered to be more soluble in water than in other solvents.

Accepted Answer

Lipids are considered to be more soluble in nonpolar solvents such as chloroform or benzene, rather than in water which is a polar solvent.

Question 14

The human genome project was embarked upon in the late 1970s with the goal of mapping the entire DNA molecule.

Accepted Answer

The Human Genome Project actually began in 1990 with the goal of mapping and sequencing the entire human genome.

Question 15

Lipids are soluble in aqueous solutions such as blood and cytoplasm.

Accepted Answer

Lipids are not soluble in aqueous solutions. They are hydrophobic, meaning they repel water and tend to clump together in the presence of water. Specialized transporters, such as lipoproteins, are needed to move lipids through the blood and into cells.

Question 16

Monosaccharides typically rearrange in aqueous solution to form double helix structures.

Accepted Answer

Monosaccharides do not form double helix structures in aqueous solution. However, they can participate in a process called mutarotation, where they interconvert between different anomers (alpha and beta configurations) and linear forms.

Question 17

The structure of a carbohydrate shows that water molecules are connected to carbon atoms.

Accepted Answer

Carbohydrates are composed of carbon, hydrogen, and oxygen atoms, typically in a ratio of 1:2:1, but they do not have water molecules directly connected to carbon atoms. Instead, they have hydroxyl groups (-OH) and carbonyl groups (C=O) attached to the carbon backbone.

Question 18

The four main classes of biochemical compounds are carbohydrates,lipids,proteins and nucleic acids.

Accepted Answer

This is true.

Question 19

The smallest structural unit of a living organism is the cell nucleus.

Accepted Answer

The smallest structural unit of a living organism is the cell. While the cell nucleus is important, it is not the smallest unit.

Question 20

Carbohydrates provide short term energy storage in cells.

Accepted Answer

Carbohydrates are broken down into glucose, which is used as a source of energy by cells. This energy is stored in the form of ATP (adenosine triphosphate), which can be quickly accessed by the cell whenever needed. However, carbohydrate storage is limited and can only provide short term energy.

Quiz 19: Biochemistry