PROTEIN SYNTHESIS

PROTEIN SYNTHESIS the process of building peptide chains and proteins from amino acids using information provided by genes in a two-step process of transcription and translation

TRANSCRIPTION process by which information encoded in genes (DNA) is used to make messenger RNA

DEOXYRIBONUCLEIC ACID (DNA) nucleic acid that stores the body’s genetic information; made of a double strand of nucleotide subunits

MESSENGER RIBONUCLEIC ACID (mRNA) the type of RNA that carries the genetic code for a specific protein from the nucleus to the cytoplasm where proteins are made

TRANSLATION process by which mRNA is decoded by ribosomes to synthesize proteins in the correct amino acid sequence

When we eat protein in foods, the body breaks them down into amino acids and then uses the amino acids to produce the particular protein needed. The nearly 22,000 proteins produced in the human body are generated through a two-step process of protein synthesis. In the first step of protein synthesis, known as transcription, segments of deoxyribonucleic acid (DNA) called genes provide the “instructions” for the assembly of amino acids into particular proteins. These instructions are transcribed into messenger ribonucleic acid (mRNA). In the second step of protein synthesis, called translation, ribosomes translate the instructions into proteins. (INFOGRAPHIC 8.3)

INFOGRAPHIC 8.3 Protein Synthesis In cells, sequences of DNA called genes provide the instructions for the synthesis of every protein in our body. This is a two-step process that begins in the nucleus with gene transcription and is completed in the cytoplasm with translation.
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Question 8.3

image What information does mRNA provide during protein translation?

Messenger RNA (mRNA) carries the instructions for building a protein—the specific amino acid sequence necessary for the assembly of a specific protein.

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Once the synthesis of the protein is completed, it has not necessarily taken its final form. The unique nature of each amino acid in the sequence prevents the protein from remaining in a straight line. Interactions between these amino acids in the sequence cause the protein to fold into a three-dimensional shape. The shapes determine the function of the protein. (INFOGRAPHIC 8.4)

INFOGRAPHIC 8.4 Protein Folding The overall shape of a protein molecule determines its function, and how it interacts with other molecules. For proteins to function properly, they must retain their three-dimensional shape.
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Question 8.4

image What provides the information necessary to specify the three-dimensional shape of a protein?

The sequence of the amino acids determines the three-dimensional shape of the protein.