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Biology

A Level

What are the main components and properties of a plasma membrane?

A plasma membrane is composed mainly of an unordered phospholipid bilayer (double layer) embedded with membrane proteins which forms a thin flexible sheet. This gives the...

Answered by Katie D. • Biology tutor

23158 Views

Describe the effects of cigarette smoke on the airway.

Cigarette smoke contains a number of harmful chemicals such as Tar, Carbon monoxide and Nicotine.

Tar settles on the lining of the airway and alveoli, increasing the diffusion distance for the gase...

Answered by Kristen D. • Biology tutor

5465 Views

What are Enzymes and how do they work?

What is an Enzyme?
Enzymes have an essential role in the reactions in the body from respiration to digestion. Enzymes are globular proteins with a specific tertiary shape.

Answered by Katie D. • Biology tutor

21615 Views

What is the structure of proteins?

Most proteins have 3 or 4 levels of structure which include the primary, secondary and tertiary structure, with many also having a Quaternary structure. Firstly, the primary structure is the unique sequen...

Answered by Katie D. • Biology tutor

5194 Views

How does a cell produce energy?

The process through which cells convert organic molecules into energy is called “respiration”. This process occurs in every cell of every organism and is vital to its survival.

Usually, respiration...

Answered by Francesco G. • Biology tutor

26376 Views