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

Which two elements are always found in all amino acids?

Hydrogen and calcium

Sulfur and phosphorus

Carbon and nitrogen

Oxygen and magnesium

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Verified step by step guidance

Step 1: Begin by understanding the structure of amino acids. Amino acids are the building blocks of proteins and have a general structure consisting of a central carbon atom (called the alpha carbon), an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group).

Step 2: Identify the key elements present in the amino acid structure. The amino group contains nitrogen (N), the carboxyl group contains carbon (C) and oxygen (O), and the central alpha carbon is bonded to a hydrogen atom and the side chain.

Step 3: Recognize that while the side chain (R group) can vary and may contain additional elements like sulfur or phosphorus, the core structure of all amino acids always includes carbon (C) and nitrogen (N).

Step 4: Eliminate incorrect options based on the core structure. For example, hydrogen and calcium are not consistently present in all amino acids, nor are sulfur and phosphorus. Oxygen is part of the carboxyl group but magnesium is not a component of amino acids.

Step 5: Conclude that the two elements always found in all amino acids are carbon (C) and nitrogen (N), as they are integral to the amino group and the central structure of the molecule.