L16: Covalent Bonds

• What is vitalism in the context of chemistry and biology?

  Vitalism is the belief that life is distinctly different from principles of chemistry and physics.
• What disproved the concept of vitalism?

  The synthesis of urea in the lab in 1828 disproved vitalism.
• What are the main types of noncovalent interactions?

  Main types include ionic interactions, dipole interactions, dipole-ion interactions, hydrogen bonds, dispersion forces, steric repulsion, and hydrophobic interactions.
• How do covalent and noncovalent bonds function in protein digestion?

  • Protein digestion involves breaking covalent bonds in the stomach.
  • Pepsin is active in the stomach and denatured in the duodenum.
  • Noncovalent bonds control the function of enzymes like pepsin and trypsin.
• What is the role of trypsin in protein digestion?

  • Trypsin is active in the duodenum and produced by the pancreas.
  • It is initially made as inactive trypsinogen to prevent self-digestion.
  • Trypsin cleaves other enzymes to activate them.
• What are the components of an atom?

  An atom consists of electrons, protons, and neutrons.
• What determines the atomic number of an element?

  The atomic number is determined by the number of protons in the nucleus.
• What are isotopes?

  Isotopes are variants of an element that have the same number of protons but different numbers of neutrons.
• Which elements are primarily needed in biology?

  The main elements needed in biology are hydrogen (H), carbon (C), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S).
• How do atoms achieve full electron shells?

  Atoms achieve full shells by sharing electrons with other atoms.
• What is the significance of group and period in the periodic table?

  Groups indicate how many electrons are in the outer shell, while periods indicate when a new shell starts filling up.
• Why are covalent bonds considered directional?

  Covalent bonds are directional because they convey shape and have specific angles between them.
• What are isomers?

  Isomers are molecules that have the same molecular formula but different arrangements of atoms in space.
• What are the two main types of isomers?

  • Structural isomers: Same molecular formula but different arrangement of bonds.
  • Stereoisomers: Same molecular formula and arrangement of bonds but differ in orientation of bonds in space.
• What is the difference between glucose and fructose in terms of functional groups?

  Glucose is an aldehyde, while fructose is a ketone.
• How do the Fischer and Haworth projections differ for glucose?

  • Fischer projection: Vertical bonds behind the plane, horizontal bonds in front.
  • Haworth projection: Bonds pointing down correspond to the right hand in Fischer.
• What are positional isomers?

  Positional isomers have the same molecular formula but differ in the position of a functional group.
• What defines a chiral carbon?

  A chiral carbon has four different groups attached to it.
• What are stereoisomers in biology?

  • Stereoisomers are molecules that differ in the orientation of groups attached to a chiral carbon.
  • They are non-superimposable.
• What role do glycosidic bonds play in carbohydrates?

  Glycosidic bonds connect glucose molecules, forming different optical isomers and polysaccharides.
• What are the properties of glucose polymers?

  • Fast breakdown for energy.
  • Fiber for structure.
  • Amylose and amylopectin break down for energy.
• What are the key concepts summarized in the study material?

  Key concepts include atom structure, covalent bonds, isomers, and sugar chemistry.