Basic Science

Types of Carbohydrates: Monosaccharides and Polysaccharides

len Alfred Ajibola - 25th June, 2021 @ 11:15 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

What are Carbohydrates?

Carbohydrates are classes of food composed of carbon, hydrogen and oxygen (CHO) in the ratio of 1:2:1. They are the body's first choice for generating the energy needed to enable us go about our daily activities.

However, fats and proteins can also act as sources of energy but they aren't the body's first choice. As a matter of fact, fatty foods contain a higher calorie of energy (when compared with an equal amount of carbohydrate food). Meanwhile, carbohydrate and protein diets (of equal quantities) are considered to contain similar amount of calories.

Please read on the concept of food here.

Note: Each gram of carbohydrate provides 4 calories of energy. Interestingly, they are the main source of energy for the muscle and brain cells respectively. Understand that other cells outside the brain and muscles can effectively use fats and proteins as alternative sources of energy if the need arises.


Types of carbohydrates?

All carbohydrates are sugars

When we eat rice, yam, table sugar or even glucose, we are essentially eating carbohydrates or sugars. These sugars can be put into four types or classes or categories. They are:

  1. Polysaccharides

  2. Monosaccharides

  3. Disaccharides

  4. Oligosaccharides

Please read on disaccharides and oligosaccharides here.

Below are explanations on polysaccharides and monosaccharides respectively.

  • Polysaccharides

Polysaccharides are complex sugars. They are generally grouped into 4 types. These are:

  1. Starch
  2. Glycogen
  3. Chitin
  4. Cellulose

  • Food containing starch are widely eaten forms of carbohydrates. They include rice, cassava, yam, potatoes, maize, millet and other forms of cereals. Generally, they are the type of polysaccharides we typically eat (in their cooked form) whenever we enjoy a carbohydrate meal.
  • Glycogen is derived from glucose. In simple terms, cooked starch eaten by humans are broken down into glucose which are eventually absorbed into the blood stream and conveyed to the liver. Here, glucose is converted into glycogen (by the joining of many glucose molecules through various glycosidic linkages). The formed glycogen is stored in the liver for a later use when the blood becomes short of glucose at meal intervals.
  • Chitin is a major component of insect and anthropod's skeleton. It functions to protect their internal organs, while also supporting the organisms where they are present.
    Please read more on chitin as a skeletal material here.
  • Cellulose is a major component of a plant's cell wall, (which is often called a cellulose cell wall). Infact, this is what distinguishes a plant cell from an animal cell. Cellulose can't be digested when eaten by humans; hence they function as roughages.
    You can read on the differences between plants and crops here.

Polysaccharides have got a general formula and that's 'Cx(H2O)y'. In this formula, 'x' is always a large number between 200 and 2500. This is however dependent on the repeating monosaccharides.

The image below shows the polysaccharide (starch) formed from many repeating glucose molecules. Glucose is a monosaccharide in this instance.
Starch formed from repeating glucose molecules - Len Academy

You can read on molecular mass and molar mass with their calculations here.

From the general formula above, we can infer that polysaccharides are large molecules composed of repeating units of another type of sugar called monosaccharides or simple sugars.


  • Monosaccharides

Also called simple sugars, they are the end products (or final broken down products) of polysaccharides. They consist of one sugar unit and thus cannot be further broken down.

Consider the narrative below:

  • After we had eaten a starchy food (polysaccharide), various enzymes produced by our bodily cells break down the ingested starch (which is always eaten in its cooked form). The enzymes first digest (breakdown) the starchy food into a double sugar (called disaccharide), then finally into monosaccharides (mainly glucose). This breakdown process of ingested food is termed digestion.

The monosaccharide (glucose) is eventually absorbed into the blood stream (through tiny villi from the small intestine). Eventually, they are conveyed by the blood to various bodily cells where they are utilized for energy production in the mitochondria.

Please read on the basic characteristics of life here.

Understand that glucose is the major monosaccharides utilized in the generation of energy or Adenosine TriPhosphate (ATP) in the cell's power house (mitochondria).

The process of generating ATP in the mitochondria of cells is usually accomplished with the utilization of oxygen; hence the overall process is termed aerobic respiration

Note: Respiration can also occur in the absence of oxygen; and this is termed anaerobic respiration.

Monosaccharides generally have a chemical formula of 'C6H12O6'. This is shown in the image below, with each containing 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms respectively.
Monosaccharides - Glucose, Galactose and Fructose - Len Academy

Glucose, fructose and galactose are the three major types of monosaccharides.

Functionally, fructose is involved in the body's metabolism while galactose has shown to be useful for the normal functioning of erythrocytes or red blood cells.
Please read more on red blood cells and hemoglobin here.

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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