Question 1

What are the main types of biological molecules studied in Edexcel A Levels Biology B?

Accepted Answer

In Edexcel A Levels Biology B, the main types of biological molecules include carbohydrates, proteins, lipids, and nucleic acids. These molecules are essential for various biological functions, including energy storage, structural support, and genetic information transmission.

Question 2

How do enzymes function as biological catalysts in living organisms?

Accepted Answer

Enzymes are proteins that act as biological catalysts, speeding up chemical reactions in living organisms without being consumed in the process. They work by lowering the activation energy required for reactions, allowing them to occur more efficiently. Enzymes are highly specific, meaning each enzyme only catalyzes a specific reaction or set of reactions.

Question 3

What role do carbohydrates play in biological systems according to the Edexcel A Levels curriculum?

Accepted Answer

Carbohydrates serve several critical roles in biological systems. They are a primary source of energy, with glucose being a key energy molecule. Carbohydrates also provide structural support in cell walls of plants (cellulose) and are involved in cell recognition and signaling processes.

Question 4

Why are lipids important in cellular structures and functions?

Accepted Answer

Lipids are crucial for forming cellular membranes, such as the phospholipid bilayer, which provides a barrier and structural integrity to cells. They also serve as long-term energy storage molecules and play roles in signaling pathways and insulation in organisms.

Question 5

How do nucleic acids contribute to genetic information storage and transmission?

Accepted Answer

Nucleic acids, including DNA and RNA, are vital for storing and transmitting genetic information. DNA holds the instructions for building proteins, which are essential for all cellular functions. RNA is involved in translating these instructions during protein synthesis. These processes are fundamental to heredity and the functioning of all living organisms.

Biological molecules

Biological molecules — frequently asked questions

Biological molecules

Biological molecules — frequently asked questions