Small Molecules
Problem Set - Small Molecules (Campbell Chapters 2 and 3)
1. What are the SPONCH elements and what is common among these elements that make them suitable for life? State the four most frequently occurring of the SPONCH elements. Which of the SPONCH elements is found in each of the large biomolecules (carbohydrates, proteins, lipids, nucleic acids).
The SPONCH elements are Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon and Hydrogen. These are the five key elements that compose living things. The four most frequently occurring of the SPONCH elements are, carbon, hydrogen, nitrogen and oxygen. Carbon is found in each of the large biomolecules.
2. Outline the difference between an atom and an ion.
An atom has the same amount of protons as electrons, so it is neutral in charge. It is a single particle of a chemical event. When an atom gains or loses an electron it becomes an ion. Ions are charged, while atoms are uncharged. An ion has either a positive or negative charge because there are unequal numbers of electrons and protons. A positive ion is called a cation, while a negative ion is called an anion.
3. Define electronegativity and explain what it has to do with the behavior of outer-shell electrons.
Electronegativity is the attraction of a given atom for the electrons of a covalent bond. The more electronegative an atom, the more strongly it attracts shared electrons.
4. What is a polar molecule? What is the nature of a hydrogen bond?
A polar molecule is a molecule (such as water) with an uneven distribution of charges in different regions of the molecule. A hydrogen bond is a weak type of force that forms a special type of dipole-dipole attraction, which occurs when a hydrogen atom bonded to a strongly electronegative atom exists in the area of another electronegative atom with a lone pair of electrons. These bonds are weaker than true covalent and ionic bonds.
5. Draw an electron dot
1. What are the SPONCH elements and what is common among these elements that make them suitable for life? State the four most frequently occurring of the SPONCH elements. Which of the SPONCH elements is found in each of the large biomolecules (carbohydrates, proteins, lipids, nucleic acids).
The SPONCH elements are Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon and Hydrogen. These are the five key elements that compose living things. The four most frequently occurring of the SPONCH elements are, carbon, hydrogen, nitrogen and oxygen. Carbon is found in each of the large biomolecules.
2. Outline the difference between an atom and an ion.
An atom has the same amount of protons as electrons, so it is neutral in charge. It is a single particle of a chemical event. When an atom gains or loses an electron it becomes an ion. Ions are charged, while atoms are uncharged. An ion has either a positive or negative charge because there are unequal numbers of electrons and protons. A positive ion is called a cation, while a negative ion is called an anion.
3. Define electronegativity and explain what it has to do with the behavior of outer-shell electrons.
Electronegativity is the attraction of a given atom for the electrons of a covalent bond. The more electronegative an atom, the more strongly it attracts shared electrons.
4. What is a polar molecule? What is the nature of a hydrogen bond?
A polar molecule is a molecule (such as water) with an uneven distribution of charges in different regions of the molecule. A hydrogen bond is a weak type of force that forms a special type of dipole-dipole attraction, which occurs when a hydrogen atom bonded to a strongly electronegative atom exists in the area of another electronegative atom with a lone pair of electrons. These bonds are weaker than true covalent and ionic bonds.
5. Draw an electron dot