Biology Lecture Review: Proteins, Nutrients, Water, and Vitamin C Testing

Flashcards covering protein structure and function, essential nutrients (minerals, vitamins, dietary fibre), water functions, and the DCPIP test for Vitamin C based on the provided notes.

Which chemical elements compose proteins?

Proteins are made of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) atoms. Some proteins also contain sulfur (S) atoms.

What are the basic building blocks of proteins?

Amino acids are the basic building blocks of proteins.

How is a dipeptide formed and how is it broken down?

A dipeptide is formed from the condensation of two amino acids linked by a peptide bond. It can be broken down into amino acids.

How does a polypeptide form a functional protein structure?

A polypeptide coils and folds in a specific way into a 3-dimensional structure. A protein may consist of one or more polypeptides with a unique shape that allows specific functions.

What is the difference between non-essential and essential amino acids?

Non-essential amino acids can be produced by our body, whereas essential amino acids need to be obtained from the diet.

What are the main functions of proteins in the human body?

Proteins are used for growth and repair, to produce enzymes, antibodies, and some hormones, and as an energy source when stored carbohydrates and fats are used up.

How is protein test paper used to detect proteins?

The test end of the protein test paper is dipped into the food sample. If protein is present, the color of the test end changes.

How do minerals and vitamins differ in terms of their chemical classification?

Minerals are inorganic food substances, while vitamins are organic food substances.

Do minerals and vitamins provide energy to the body?

No, they have no energy value, but they are important in building body tissues and regulating many metabolic reactions.

What is insoluble dietary fibre made of, and what is its function?

Insoluble dietary fibre consists mainly of cellulose from plant cell walls. It adds bulk to food to stimulate peristalsis in the intestine.

What is the function of Vitamin A in the human body?

Vitamin A is fat soluble and helps in forming a pigment in the retina.

What is the function of iron, and what deficiency disease is caused by a lack of iron?

Iron forms haemoglobin in red blood cells. A lack of iron leads to the deficiency disease anaemia.

What is the main function of Vitamin C?

Vitamin C is water soluble and helps the growth and repair of connective tissues.

What are the functions of Vitamin D and Calcium in the body?

Vitamin D promotes the absorption of calcium and phosphate ions. Calcium is involved in blood clotting, muscle contraction, nervous system function, and bones development.

What role does water play as a transport medium in the body?

Blood contains about 90% water and carries dissolved nutrients, wastes, and gases around the body.

How does water function as a reactant and a reaction solvent?

As a reactant during photosynthesis, food is produced from water and carbon dioxide. As a solvent, water in cytoplasm allows a lot of chemical reactions to take place.

How does water act as a cooling agent and a supporting agent?

As a cooling agent, the evaporation of sweat takes away heat from the body when body temperature is high. As a supporting agent, water gives shape to eyeballs and keeps seedling cells turgid so they stand upright.

What is the observation when Vitamin C is added to DCPIP solution?

If Vitamin C is present, DCPIP solution changes from blue to colourless. If Vitamin C is absent, DCPIP solution remains blue.

How does the concentration of Vitamin C in a sample affect the number of drops required to decolorize DCPIP solution?

A sample with a higher concentration of Vitamin C requires fewer drops to turn DCPIP solution colourless compared to a sample with a lower concentration.