Exam 1 Flashcards (Chapters 1-3)

Scientific Method

• Research method with defined steps including experiments and observations.
• Hypotheses do not have to be correct for tests to be valid.

Reasoning Types

• Inductive reasoning: employed in descriptive science for drawing general conclusions.
• Deductive reasoning: used in hypothesis-based science to derive predictions from general principles.

Types of Science

• Basic science: focuses on expanding knowledge through discoveries without immediate practical application.
• Applied science: targets solving real-world problems using scientific principles.

Energy in Ecosystems

• Energy enters ecosystems primarily as light.
• Energy exits ecosystems mainly as heat.

Atomic Theory

• All matter consists of tiny particles called atoms.

Subatomic Particles and Atomic Characteristics

• Subatomic particles include protons, neutrons, and electrons.
• Atomic number refers to the number of protons in an atom.
• Atomic mass is the average mass of all isotopes of an element.

Electron Arrangements

• Electron configuration details the arrangement of electrons in an atom's orbitals.
• Electrons are easiest to remove from the valence shell, the outermost layer of electrons.
• An element’s group number indicates the number of electrons in its valence shell.

Stability and Electron Count

• Stability in elements is achieved with eight valence electrons.

Chemical Bonds

• Covalent bond: formed through the sharing of electrons; stronger than ionic bonds.
• Ionic bond: established via attraction between oppositely charged ions.

Bond Strength

• Covalent bonds are generally stronger than ionic bonds.

Electrostatic Interactions

• Occur between charged particles, where opposites attract.

Polarity and Electronegativity

• Polarity of molecules is determined by electronegativity, which increases as one moves up and to the right on the periodic table.
• Polar molecules possess partial charges and mix well with water (hydrophilic).
• Nonpolar molecules have no partial charges, do not mix with water (hydrophobic).

Ion Types

• Cation: an ion with a positive charge.
• Anion: an ion with a negative charge.

Hydrogen Bonds

• Formed by attraction between a slightly positive hydrogen atom and a slightly negative atom.

Amino Acids and Hydrophilicity

• Hydrophilic amino acids have side chains containing oxygen and hydrogen.
• Hydrophobic amino acids have side chains composed of carbon.

Protein Structures

• Primary structure: sequence of amino acids in a polypeptide.
• Secondary structure: formed by links between amino acids through hydrogen bonds.
• Tertiary structure: three-dimensional shape resulting from interactions between R groups of amino acids.
• Quaternary structure: arrangement of multiple polypeptide chains.

Protein Structure Stabilization

• Tertiary structure is stabilized by salt bridges, hydrogen bonds, disulfide bridges, and hydrophobic interactions.

Denaturation Causes

• Factors include temperature changes, pH alterations, exposure to organic solvents, and mechanical stress.

Fats Classification

• Saturated fats: solid at room temperature and lack double bonds.
• Unsaturated fats: liquid at room temperature and contain double bonds.

Chemical Processes

• Hydrogenation: process that converts unsaturated fats to saturated fats by breaking double bonds.
• Saponification: reaction between fat (acid) and a strong base that produces glycerol and soap (fatty acid salt).

Soap Characteristics

• Soap is amphipathic, possessing both hydrophobic and hydrophilic properties.

Melting Point Comparison

• Unsaturated fats have a lower melting point compared to saturated fats.