Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

3. Amino Acids

Amino Acid Groups

Biochemistry

3. Amino Acids

Amino Acid Groups

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Multiple Choice

How many different types of standard amino acids are encoded by the genetic code as shown on a typical codon chart?

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Verified step by step guidance

Understand the genetic code: The genetic code is a set of rules by which nucleotide sequences in mRNA are translated into amino acid sequences during protein synthesis. Each codon (a sequence of three nucleotides) corresponds to a specific amino acid or a stop signal.

Review the codon chart: A typical codon chart shows all 64 possible codons (4 nucleotides raised to the power of 3, since there are 4 bases: A, U, G, C). These codons encode amino acids or serve as stop signals.

Identify the standard amino acids: The genetic code encodes 20 standard amino acids, which are the building blocks of proteins. These amino acids are encoded by specific codons, and some amino acids are encoded by multiple codons (a phenomenon called codon redundancy or degeneracy).

Consider special cases: In addition to the 20 standard amino acids, there are rare cases where the genetic code can encode selenocysteine (Sec) or pyrrolysine (Pyl), which are considered non-standard amino acids. These are encoded by specific codons under special circumstances, but they are not part of the standard set.

Conclude the answer: Based on the codon chart and the standard genetic code, the number of standard amino acids encoded is 20. This is the correct answer to the question.