Biology · Chemistry

Carbohydrates and Biomolecules

986 Questions

Carbohydrates and biomolecules questions test your understanding of sugars, monosaccharides, and metabolic substrates. The topic covers food transportation in plants and the biochemical properties of sweeteners. Practicing these questions builds a strong foundation for exam preparation.

Disaccharides and monosaccharidesArtificial sweetenersGlycogen storagePlant food transportGlycoprotein hormones

Carbohydrates and Biomolecules Questions

Multiple choice biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

Plant transfers glucose in the form of sucrose in order to

  1. Increase energy storage

  2. Provide efficient energy transfer

  3. Remove it in between reactions

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Starch and sucrose are more efficient forms in which the energy can be stored when compared to glucose. The starch is not soluble in water. Hence, the sucrose which is soluble in water is the form which is used for transport. This structural form increases the efficient energy transfer. Sucrose is not as reactive as glucose. This helps to prevent the chemical reactions which can convert the sucrose while transport. 

Thus, the correct answer is option D. 

Multiple choice biology transport in plant transport in the phloem of plants vascular tissue permanent tissue

Phloem transports sugar in the form of

  1. Glucose

  2. Sucrose

  3. Cellulose

  4. Starch
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sugars are synthesized as glucose and fructose, translocated as sucrose and stored as starch for long-term storage in plants. Translocation of organic nutrients from the region of source or supply to the region of utilization is mostly in the form of sucrose. Sucrose is water soluble and more efficient in energy storage as compared to the glucose and fructose as well as glucose is more reactive and hence, phloem transports sugar in the form of sucrose.

Thus, the correct answer is option B.

Multiple choice evs nutrition and its deficiency general functions of food nutrition and its need in plants nutrition and its need

Our food mainly contains

  1. Carbohydrates

  2. Cellulose

  3. Sucrose

  4. Glucose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carbohydrates are the major energy yielding macromolecules. Our food mainly consists of carbohydrates. The carbohydrates can be simple monosaccharides or disaccharides or complex polysaccharides. Cellulose, glucose, sucrose, starch are all various types of carbohydrates.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

In the presence of glucose and lactose. Escherichia coli utilizes glucose. However, lactose also enters the cells because.

  1. low level of permease is always present in the cell

  2. it uses the same transporter as glucose

  3. it diffuses through the bacterial cell membrane

  4. it is transported through porins
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Even when glucose is preferred, a basal, low level of lactose permease is constitutively expressed in E. coli, allowing some lactose to enter the cell to induce the lac operon.

Multiple choice bio-chemistry biochemical techniques methods of purification of organic compounds methods of purification - organic compounds chromatography

Osazone formation is used to separate and identify.

  1. Alcohols

  2. Carboxylic acids

  3. Carbohydrates

  4. Starch
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Osazones are characteristic crystalline derivatives formed by the reaction of reducing sugars (carbohydrates) with phenylhydrazine. They are used to identify specific sugars.

Multiple choice biology food for health fats fats and their test different nutrients in food

Which of the following has the highest calories per gram?

  1. Proteins

  2. Fats

  3. Sugar

  4. Glucose
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Calories are needed to provide energy so the body functions properly. The number of calories in a food depends on the amount of energy the food provides. The number of calories a person needs depends on age, height, weight, gender, and activity level. People who consume more calories than they burn off in normal daily activity or during exercise are more likely to be overweight.

The amount of energy one will get from carbohydrate, protein and fat is measured in calories per gram. Fats have the most energy and proteins have the same amount as carbohydrates, but their value as a source of energy is determined by more than the calories gained from one gram.
Fat: 1 gram = 9 calories 
Protein: 1 gram = 4 calories 
Carbohydrates: 1 gram = 4 calories

Therefore, the correct answer is option B.

Multiple choice biology food for health fats fats and their test different nutrients in food

Long term energy storage occurs in the form of

  1. Glucose

  2. Amino acids

  3. Glycogen

  4. Fat
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

While glycogen is used for short term energy storage in the liver and muscles, fat is the primary form for long term energy storage in the body due to its high energy density.

Multiple choice biology food for health fats fats and their test different nutrients in food

The molecule used by most animals for long term energy storage is

  1. Starch

  2. Fat

  3. Cholesterol

  4. Glycogen
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The primary cellular function of fatty acids is long term energy storage. The body stores small amount of excess nutrients as triglycerides for storage. Triglycerides are efficient energy storing molecules as more energy can be stored in fat than in glycogen. Fat contains 9 kcal per gram whereas carbohydrates and protein only contain 4 kcal per gram. In other words, fat is more calorie dense so can hold a greater amount of energy in a smaller space
So, the correct answer is 'Fat'
Multiple choice biology food for health fats fats and their test different nutrients in food

A gram of butter provides more energy that a gram of sugar because

  1. Butter is an animal product

  2. Butter has more carbon-hydrogen bonds

  3. Butter is more completely absorbed

  4. Butter contains more ATP
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbohydrates which includes  sugars and starches, contain 4 calories per gram, and are considered one of the main sources of energy for the human body. Fats on the other hand give 9 calories per gram,which is approximately 2.5 times more energy than carbohydrates. Moreover, fats contain more carbon-carbon and carbon-hydrogen bonds than carbohydrates or proteins and are therefore richer in energy. 

Therefore, the correct answer is option B.

Multiple choice biology food for health fats fats and their test different nutrients in food

A gram of butter provides more energy than a gram of sugar because

  1. Butter is digested slowly

  2. Butter has more carbon-hydrogen bonds

  3. Butter is more completely absorbed

  4. Butter contains more ATP
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A gram of butter provides more energy than a gram of sugar because butter has more carbon-hydrogen bonds.

The carbohydrates are the compounds which provide energy to living cells. They are compounds of carbon, hydrogen and oxygen with a ratio of two hydrogens for every oxygen atom. The carbohydrates we use as foods have their origin in the photosynthesis of plants. They take the form of sugars, starches, and cellulose.

Multiple choice biology food for health fats fats and their test different nutrients in food

A gram of butter provides more energy than a gram of sugar because

  1. Butter is an animal product.

  2. Butter has more carbon-hydrogen bonds.

  3. Butter is more completely absorbed.

  4. Butter contains more ATP.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fat contains 9 kcal per gram, whereas carbohydrates and protein only contain 4 kcal per gram. 

Triglycerides or fats are composed of one molecule of glycerol and joined via ester bonds with three molecules of fatty acids. Fatty acids are long chains of carbon and hydrogen usually between 14-24 carbons long. Due to the abundance of C and H, fatty acids are very hydrophobic and are not very soluble in water. 
Fatty acids come in two major types, saturated and unsaturated. Saturated means that they have no double bonds. Unsaturated means that it contains double bonds. Generally, saturated fats (butter) have a high melting point so that they are a solid at room temperature. Unsaturated fats have a lower melting point and are a liquid at room temperature. Margarine is made by hydrogenating (adding H) to unsaturated vegetable oils increasing the amount of saturation and thus, the melting point (so it will be a solid). 

Multiple choice chemistry chemical kinetics kinetic study of some first order reactions rate of chemical reaction endothermic and exothermic reactions

Inversion of cane sugar in dilute acid is:

  1. bimolecular reaction

  2. pseudo-unimolecular reaction

  3. unimolecular reaction

  4. trimolecular reaction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

${ C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 }+{ H } _{ 2 }O\xrightarrow [  ]{ \quad { H }^{ + }\quad  } { C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }+{ C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }$
Rate $=k\left[ { C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 } \right] \left[ { H } _{ 2 }O \right] $
When water is in excess, its concentration will be constant.
$\therefore $ Rate $={ k }^{ ' }\left[ { C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 } \right] $
The reaction is, therefore, pseudo first order or pseudo unimolecular reaction.

Multiple choice chemistry chemical kinetics kinetic study of some first order reactions rate of chemical reaction endothermic and exothermic reactions

The inversion of cane sugar into glucose and fructose is:

  1. $I$ order
  2. $II$ order
  3. $III$ order

  4. zero order
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Inversion of cane sugar follow Ist order reaction while its molecularity is 2 and reaction is given by
$ \implies C _{12}H _{22}O _{11} +H _2O \rightarrow C _6 H _{12}O _6 + C _6H _{12}O _6$

Here the rate of reaction is dependent on only $C _{12}H _{22}O _{11}$.