Basic Science

Carbohydrates: Disaccharides and Oligosaccharides

len Alfred Ajibola - 25th June, 2021 @ 11:09 AM

Topics in Basic Science

What is science? Qualities of a scientist Resources from living things Resources from animals Importance of immunization Types of Carbohydrates: Monosaccharides and Polysaccharides Carbohydrates: Disaccharides and Oligosaccharides Len Academy Examination Questions for Basic Science, JSS2, 2nd Term Len Academy Examination Questions for Basic Science, JSS3, 3rd Term Len Academy Examination Questions for Basic Science, JSS3, 2nd Term Primates: Characteristics of Primates Effects of improper waste management Waste Management: Causes of waste in the society Concept of mass and weight Mineral Salts: Sources, functions and deficiencies of macronutrients Sources, functions and deficiencies of micronutrients Len Academy questions for Basic Science JSS1 Len Academy mid-term test questions for Basic Science JSS1, 2nd Term Microorganisms causing food, water and air borne diseases Vector borne organisms and the diseases they cause Bones of the Human Skeleton

Academic Questions in Basic Science

Please click here to see all Questions and Answers

Which of the following diseases is associated with river blindness?

  • A. Anthrax

  • B. Lawnmower Disease

  • C. Onchocerciasis

  • D. Devil's Crunch

  • E. Trypanosomiasis

  • F. Tularemia

The vector for yellow fever is _____.

  • A. Aedes Mosquito

  • B. Female Anopheles Mosquito

  • C. Plasmodium

  • D. Flavivirus

  • E. Black Fly

  • F. Bacillus Anthracis

The bones of the head and face make up the skull. These bones are _____ in number.

  • A. 12

  • B. 14

  • C. 16

  • D. 18

  • E. 20

  • F. 22

Bacteria are not a constituent of our environment.

  • A. True

  • B. False

Below are types of drugs. Which of these is considered as pain killers?

  • A. Stimulants

  • B. Depressants

  • C. Opiods and Morphine Derivatives

  • D. Hallucinogens

  • E. Anabolic Steroids

  • F. Cannabinoids

Which of the following statement is false concerning drugs?

  • A. Drugs can be inhaled

  • B. Drugs can be injected directly into the bloodstream 

  • C. Drugs can be eaten

  • D. Drugs exist exclusively in the forms of tablets and syrups

  • E. Drugs can be placed under the tongue

  • F. Drugs can be taken with water or another liquid

Vaccination involves a process of introducing pathogens or germs into a person in order to prevent such person from the diseases they cause.

  • A. True

  • B. False

With regards to the human health, foreign bodies are best regarded as _____.

  • A. International bodies

  • B. Antilators

  • C. Antibodies

  • D. Antigens

  • E. Antibiotics

  • F. Antidotes


Carbohydrates, often referred to as sugars or saccharides or carbs, are one of the six classes of food. The others include protein, fats and oils, vitamins, mineral salts and water.

Carbohydrates are the body's first choice of energy and are typically eaten in the form of cooked starch. They are subsequently broken down into glucose, an absorbable and usable form of carbohydrate by the body cells. However, athletes may choose to have their carbohydrate meal directly as glucose since quick energy is required for their immediate activities.

Examples of food containing carbohydrates include table sugar (sucrose), milk (contains lactose as carbohydrates), rice and cassava.

Please read on the concept of food here.


Classes of carbohydrates?

Carbohydrates are classified into four types or categories. These are:

  1. Polysaccharides

  2. Monosaccharides

  3. Disaccharides

  4. Oligosaccharides

Please read on polysaccharides and monosaccharides here.

Below are explanations on disaccharides and oligosaccharides:


  • Disaccharides

They are composed of two monosaccharides joined together. For this reason, they are also referred to as double sugars.

Disaccharides are often added as sweeteners to food. As an instance, the table sugar called sucrose is a disaccharide often used to sweeten our tea.

Maltose is another disaccharide typically used as an ingredient for making malt drinks, chocolates and candies.

The breast milk contains the disaccharide lactose. Lactose is crucial for the normal growth and development of neonates and infants.

In adults, disaccharides are non essential nutrients. This implies that we can live without them (as adults).

Please read more on nutrients here.

Below is a summary of monosaccharides (single sugars) that make up disaccharides (double sugars).

Maltose = Glucose + Glucose

Lactose = Glucose + Galactose

Sucrose = Glucose + Fructose
Disaccharides - Sucrose, Lactose and Maltose - Len Academy

Other examples of disaccharides include trehalulose and isomaltulose


  • Oligosaccharides

The term oligosaccharide has its origin in Greek language. In this regard, 'oligo' means 'few' and saccharide 'sugar'. Juxtaposing both words, oligosaccharide simple imply sugars that comprises of 3 to 10 molecules of monosaccharides.

You can attempt Len Academy questions and answers on various subjects here.

Oligosaccharides will typically occur as a family of molecules. As an instance, raffinoses (RFOs) are a family of oligosaccharides found in plants. They are formed from the combinations of galactose, glucose and fructose respectively.

Functionally, a raffinose serve as transport and storage sugars in plants. Also, they aid seed protection by absorbing it's water internally, thus making them dry, firm and preserved.

Below is an image showing the structural formula of raffinose:
Oligosaccharides - Raffinose - Len Academy

Another eample of an oligosaccharide is the fructo-oligosaccharides (FOSs). They are short chains of fructose molecules present in vegetables. They are often considered as dietary fibres which are naturally soluble.

A third example of a naturally occurring oligosaccharide is galactooligosaccharides (GOSs). They consist of short chains of galactose molecules.

It is worthy of note to state that the human milk contains an oligosaccharide called human milk oligosaccharides (HMOs). The HMOs are derived from short chains lactose molecules.

Histologically, oligosaccharides are typically present as glycans around the cells. In this instance, they perform a role in determining the blood types of humans. Also, they aid in cell adhesions.

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Amazing facts in Basic Science

According to scientific research, if the first tear drop comes from the right eye, it’s tears of joy. If it comes from the left eye, then it is as a result of pain

Dentistry is the oldest profession in the world. This is considered true because a research conducted by the University of Bologna, Italy on a 14,000-year-old skull found that one rotten tooth in the jaw had been deliberately scoured and scraped with a dental tool

Scientific research has it that the human nose can distinguish more than a trillion different odors

Tiger fur and skin - Len Academy

Tigers have striped fur. So also is their skin

Red-Billed Quelea - Len Academy

The most common wild bird in the world is native to Africa, and it's the red-billed quelea with a population estimated to be around 1.5 billion

Of all animals, mosquitoes hold the record of killing most humans annually. They are responsible for the deaths of 725,000 - 1,000,000 persons yearly

Antibiotics fights and kills bacteria. However, they do nothing to a virus

All insects have six legs. However, dragonfly has six legs but can't walk

The chin is defined as the protruding part of the face below the mouth, formed by the apex of the lower lip. It is shown below:

Chin - Len Academy

Interestingly, humans are the only animals with chin

Cranberries - Len Academy

Ripe cranberries will bounce like a ball. For this reason, they are nicknamed 'bounceberries'. They will also float in water

Notable points in Basic Science

We have six classes of food. These are:

  1. Carbohydrates

  2. Proteins

  3. Fats and Oils

  4. Vitamins

  5. Mineral Salts

  6. Water

In humans, roughages are not classified as one of the classes of food. This is so because they aren't digested. Instead, roughages facilitate the movement of bowels in the large intestine (colon); and for this reason, they can become useful in treating constipation.

Food refers to anything that is ingested by living organisms, giving them nutrients and thus enabling them to stay alive.

As an instance, 99% of a panda's diet is bamboo. In this case, bamboo is considered as food to a panda since it provides a source of nutrient and keeps it alive. This is shown in the image below:

Panda eating bamboo - Len Academy

Please read more on food here

The only process in nature that actively enriches our atmosphere with oxygen is photosynthesis. Every other process like respiration, burning and combustion takes away oxygen from it. In addition, they introduce carbon(IV)oxide (CO2) into the atmosphere.

Photosynthesis is also the only process that takes away carbon(IV)oxide (CO2) from the atmosphere.

Photosynthesis is defined as a process by which green plants manufacture food by utilizing carbon(IV)oxide and water in the presence of sunlight.

Oxygen is given off as a by-product of photosynthesis. In regards to this, it is recommended that each person plants a tree.

Matter is composed of particles which can be:

  1. Tightly packed together (as seen in solids).

  2. Loosely packed together (as seen in liquids).

  3. Completely separated (as seen in gases).

The movement of the particles of matter is a function of the overall kinetic energy present in them. You can think of kinetic energy as energy in motion.

An increase in the particles' vibrational, rotational or translational motion will imply an increase in temperature while a decrease in the particles motion (vibrational, rotational and translational) will mean a decrease in temperature. Based on this knowledge, we can therefore define temperature as the measure of the average kinetic energy possessed by the particles of matter.

You can read on the concept of matter here

Intelligence Quotient (IQ) is a score derived from a set of standardized tests developed to measure a person's cognitive abilities in relation to their age group.

IQ may also be defined as the ratio of mental age (MA) to chronological age (CA) multiplied by 100.

Below are some formulas pertaining Intelligence Quotient:

  • IQ = MA x 100 ÷ CA

  • MA = Mental age

  • CA = Chronological age

  • IQ above 100 = Brilliance

  • IQ that equals 100 = Average

  • IQ below 100 = Below Average