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protein

Definition

Proteins are large molecules made up of amino acids. Amino acids are linked together in long chains, and the order of the amino acids determines the structure and function of the protein. Proteins are found in all living things, and they play a vital role in many different processes, including:

  • Growth and repair
  • Metabolism
  • Immunity
  • Transport
  • Enzyme function

Proteins are essential for good health, and it is important to get enough protein in your diet. The recommended daily intake of protein for adults is 0.8 grams per kilogram of body weight. This means that a 70-kilogram adult should eat about 56 grams of protein per day.

There are many different sources of protein, including meat, fish, poultry, eggs, dairy products, beans, and nuts. It is important to eat a variety of protein-rich foods each day to get the nutrients your body needs.

How can the word be used?

Protein is found in many foods, such as meat, fish, eggs, and dairy products.

protein

Different forms of the word

Noun: a large molecule consisting of one or more chains of amino acids and forming part of all living cells.

Adjective: relating to protein.

Etymology

The word "protein" comes from the Greek word "proteios", which means "primary" or "of first rank".

The first recorded use of the word "protein" in English was in 1838.

Question

What foods are good sources of protein?

AQA Science Exam Question and Answer

Question:

Define a protein and discuss its significance in living organisms. Explain the role of proteins in various biological functions and provide examples of their diverse functions in cells and tissues.

Answer:

A protein is a complex organic molecule composed of amino acids, linked together in a specific sequence. Proteins are vital components of living organisms, playing essential roles in various biological functions.

Proteins are incredibly diverse and serve numerous functions within cells and tissues. Enzymes, a type of protein, act as biological catalysts, speeding up chemical reactions necessary for metabolism. Haemoglobin, another protein, transports oxygen in the blood, enabling cells to perform respiration. Antibodies are proteins that play a critical role in the immune system by recognising and neutralising foreign substances.

Structural proteins like collagen provide support and strength to tissues, while contractile proteins facilitate muscle movement. Hormones are signalling proteins that regulate various physiological processes, such as insulin controlling blood sugar levels. Proteins also participate in cell communication, DNA replication, and regulation of gene expression.