Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

18. Amino Acids and Proteins

Summary of Protein Structure

GOB Chemistry

18. Amino Acids and Proteins

Summary of Protein Structure

Previous problemNext problem

6:23 minutes

Problem 81c

Textbook Question

Consider the amino acids lysine, valine, and aspartate in an enzyme. State which of these amino acids have R groups that would:
c. form hydrogen bonds

Verified step by step guidance

Identify the R groups (side chains) of the given amino acids: lysine, valine, and aspartate. Lysine has an amino group (-NH3+) in its side chain, valine has a branched alkyl group, and aspartate has a carboxyl group (-COO−) in its side chain.

Recall the conditions for hydrogen bonding: Hydrogen bonds form between a hydrogen atom covalently bonded to an electronegative atom (like O, N, or F) and another electronegative atom with a lone pair of electrons.

Analyze the R group of lysine. The amino group (-NH3+) in lysine's side chain can participate in hydrogen bonding because nitrogen is electronegative and can interact with hydrogen bond acceptors or donors.

Analyze the R group of valine. The branched alkyl group in valine is nonpolar and lacks electronegative atoms, so it cannot form hydrogen bonds.

Analyze the R group of aspartate. The carboxyl group (-COO−) in aspartate's side chain contains oxygen atoms, which are electronegative and can act as hydrogen bond acceptors, allowing aspartate to form hydrogen bonds.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Amino Acid Structure

Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid consists of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a variable R group (side chain). The R group determines the unique properties of each amino acid, influencing how they interact with each other and with other molecules.

Hydrogen Bonding

Hydrogen bonds are weak attractions that occur between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom. In the context of amino acids, R groups that contain polar functional groups, such as hydroxyl (-OH) or amine (-NH2) groups, can participate in hydrogen bonding, which is crucial for protein structure and function.

Polarity of R Groups

The polarity of an amino acid's R group affects its ability to form hydrogen bonds. Polar R groups, which have uneven distribution of electrical charge, can interact with water and other polar molecules, facilitating hydrogen bond formation. In contrast, nonpolar R groups do not engage in hydrogen bonding, impacting the overall behavior of proteins in biological systems.