Biology: Testing for Glucose and Fats

Study Notes

Testing for Glucose

Benedict’s solution is used to test for glucose presence.
Mixing equal parts of Benedict’s solution and glucose, then heating results in an orange-red precipitate.

Fats

Fats consist of carbon, hydrogen, and oxygen, with less oxygen compared to carbohydrates.
Fats provide more than double the energy per gram compared to carbohydrates.
Functions include energy reserve during low food intake and thermoregulation.
Excess fat consumption can lead to health issues like heart diseases.
Sources of animal fats include butter, lard, meat, cheese, and milk.
Plant-sourced fats are found in margarine, nuts, and cooking oils (peanut, palm, olive).
Healthy fats are present in plant oils and fatty fish like salmon and mackerel.
Animal fats, such as lard and butter, typically contain unhealthy fats and should be consumed in moderation.

Testing for Fats

Ethanol is employed to test for fats in food.
Mixing ethanol with oil creates a clear solution.
Adding water to this mixture produces a white emulsion, indicating fat presence.

Fibre

Fibre, or roughage, is made of cellulose, indigestible by the human body.
It facilitates solid waste elimination and prevents constipation.
Adequate dietary fibre maintains healthy intestinal function.
Rich sources of fibre include fruits, vegetables, brown rice, cereals, and whole wheat bread.

Ruminants

Animals like cows, sheep, and goats can digest cellulose due to stomach bacteria in their four-chambered stomachs.

Vitamins

Vitamins are essential in small quantities for health and growth.
Vitamin deficiencies can lead to diseases such as scurvy (bleeding gums) and rickets (soft bones and stunted growth).

Proteins

Composed of long chains of amino acids that include carbon, hydrogen, oxygen, and nitrogen.
Around 20 different amino acids combine in various ways to create millions of proteins.
Proteins provide energy but primarily function to build cells, tissues, enzymes, and hormones.
Essential for growth and repair of body tissues; deficiencies can lead to kwashiorkor, characterized by muscle wasting and distended abdomen.
Protein-rich foods include meat, eggs, fish, milk, cheese, beans, nuts, and peas.

Testing for Proteins

Biuret solution tests for soluble proteins.
A violet color change occurs when Biuret solution (sodium hydroxide and copper sulfate) is mixed with protein.

Testing for Starch

Iodine solution is used to detect starch.
A blue-black color indicates the presence of starch.

Sugars

Sugars occur naturally in fruits, sugar cane, and milk.
Commonly used in confections like chocolates, candies, cakes, and soft drinks.

Description

Explore the biochemical processes related to glucose testing and the role of fats in energy supply. This quiz covers Benedict’s solution and the characteristics of fats compared to carbohydrates. Test your knowledge on these fundamental concepts in biology!