Biological Molecules Flashcards
(14 cards)
What are carbohydrates?
- Carbohydrates are organic molecules made up of Carbon, Hydrogen and Oxygen where hydrogen and oxygen are in the ratio of 2:1
- Carbohydrates may be divided into two sections, sugars and complex carbohydrates.
- Some examples of single sugars (monosaccharides) are glucose and fructose
- Some examples of double sugars (disaccharides) are glucose are maltose and sucrose.
What are complex carbohydrates ?
Complex carbohydrates are polysaccharides that are made up of many single sugars to form a large molecule
* Some examples of polysaccharides are starch, cellulose, glycogen [to refer to textbook for explanations on examples**]
What are the functions of carbohydrates?
Carbohydrates are needed
- as a substrate for respiration, to provide energy for cell activities
* - to form supporting structures
- to be converted into other organic compounds
* - for the formation of nucleic acids
* - to synthesise lubricants
- to synthesise nectar in some flowers
What are Fats?
Fats are organic molecules made up of Carbon, Hydrogen and Oxygen. The ratio of oxygen to hydrogen is much lower.
* Fats can be broken down into fatty acids and glycerol through the action of an enzyme
Where can you find fats?
- butter, cheese, fatty meat, olives, nuts, peas, beans, seeds of castor oil and palm oil
- meat of most fishes and white meat have relatively lesser fats.
- salmon and herring have a large amount of fats
What are the functions of fats?
Fats function as
* - a source or long-term storage of energy
* - an insulating material that prevents excessive heat loss
- A solvent for fat soluble vitamins and many other vital substances such as hormones
- an essential part of cells, especially in the cell membrane
* - A way to reduce water loss from the skin surface. Glands in the skin secrete an oily substance
What are Proteins?
Proteins are organic molecules made up of Carbon, Hydrogen, Oxygen and Nitrogen. Sulfur may be present.
* Proteins can be broken down into a polypeptide chain and further into amino acids with the action of an enzyme
Where can we find proteins?
Proteins can be found in animal and plant foods like milk, eggs, seafood, and meat.
Plant foods rich in protein include soya beans, nuts, grains and vegetables such as French beans.
What are the functions of proteins?
proteins are used in the
* - synthesis of new cytoplasm, for growth and repair of worn-out body cells
- synthesis of enzymes and some hormones
* - formation of antibodies to combat diseases (to be further explored in diseases chapter)
How can we identify nutrients present in our food?
We can conduct food tests to identify what organic molecules are in our food
How can we test for reducing sugars?
To test for reducing sugars (glucose, fructose, maltose), we will use the Benedict’s test.
Reducing Sugars present - blue to brick-red
Reducing Sugars absent - remain blue
How can we test for starch?
How can we test for fats?
How can we test for proteins?
