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carbohydrate

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Secondary Information

Definition

Carbohydrates are one of the three main nutrients that your body needs for energy. They are made up of carbon, hydrogen, and oxygen atoms, and their chemical formula is Cx(H2O)y.

Simple carbohydrates are the simplest form of carbohydrates and are broken down quickly by the body. They include sugars such as glucose, fructose, and lactose.

Complex carbohydrates are larger molecules that take longer for the body to break down. They include starches and fibre.

Fibre is a type of complex carbohydrate that cannot be broken down by the body. It is important for gut health and helps to keep you feeling full.

The body needs carbohydrates for energy. When you eat carbohydrates, they are broken down into glucose, which is the body's main source of energy. Glucose is used by the cells in your body to power your muscles, organs, and other tissues.

It is important to get enough carbohydrates in your diet. The recommended daily intake of carbohydrates for adults is 45-65% of total calories. However, this may vary depending on your age, activity level, and health goals.

Here are some examples of foods that are high in carbohydrates:

  • Simple carbohydrates: fruit, candy, soda, white bread, white rice
  • Complex carbohydrates: whole grains, vegetables, legumes, nuts, seeds

How can the word be used?

The body breaks down carbohydrates into glucose, which is the body's main source of energy.

carbohydrate

Different forms of the word

Noun: Carbohydrate.

Adjective: Carbohydrate.

Verb: To carbohydrate.

Plural: Carbohydrates.

Etymology

The word "carbohydrate" comes from the combination of two Greek words: "carbo", meaning "coal" and "hydrate", meaning "water". This is because carbohydrates are made up of carbon, hydrogen, and oxygen, and they contain the same ratio of hydrogen to oxygen as water.

Question

What foods are good sources of carbohydrate?

AQA Science Exam Question and Answer

Question:

A student performs a Benedict's test on a solution of glucose. The solution turns a brick-red colour.

(a) What does this result indicate about the presence of reducing sugars in the solution?

(b) Explain why the Benedict's test is a qualitative test.

Answer:

(a) The brick-red colour indicates that the solution contains reducing sugars. Reducing sugars are sugars that can donate electrons to other molecules. In the Benedict's test, the reducing sugars react with Benedict's reagent to form a brick-red precipitate of copper(I) oxide.

(b) The Benedict's test is a qualitative test because it does not give a quantitative value for the amount of reducing sugar present in the solution. The intensity of the brick-red colour can be used to give a rough estimate of the concentration of reducing sugar, but this is not very accurate.

Here are some additional points that could be included in the answer:

The Benedict's test is a specific test for reducing sugars. It does not react with non-reducing sugars, such as sucrose.

The Benedict's test is a sensitive test for reducing sugars. Even very small amounts of reducing sugar can cause the solution to turn a brick-red colour.

The Benedict's test is a relatively simple test to perform. It can be carried out in a school laboratory with relatively inexpensive equipment.