Reaction Velocity: Key Concepts

• Answers to the questions are summarized below

Reaction Velocity

• It is defined as the rate at which reactants are converted into products in a chemical reaction

Enthalpy vs Entropy

• Enthalpy is the heat content of a system at constant pressure
• Entropy is the measure of the disorder or randomness of a system

Factors Influencing Reaction Velocity

• Temperature, higher temperatures usually increase reaction rates by providing more energy
• Catalysts, they speed up reactions by lowering the activation energy required

Activation Energy

• It is the minimum energy required to start a chemical reaction
• Catalysts lower activation energy needed, accelerating the reaction

Ionization Constant of Water & Bases

• The ionization constant of water (Kw) relates to the concentration of hydrogen and hydroxide ions
• Bases affect the concentration of hydroxide ions, influencing Kw

Spontaneous Reaction & Gibbs Free Energy

• A spontaneous reaction occurs without external energy input
• Gibbs Free Energy (ΔG) determines spontaneity: negative ΔG indicates a spontaneous reaction

Decomposition of Ni(CO)4

• Given ΔG°r = 0, ΔH° = +189.9 kJ/mol, and ΔS° = +500.5 J/mol
• The temperature at equilibrium can be calculated using ΔG = ΔH - TΔS

Protein Formation

• Proteins are formed from amino acid monomers linked by peptide bonds
• Nucleic acids are not directly involved in forming the primary structure of a protein
• Nucleic acids contain the genetic code that dictates the amino acid sequence

Sulfur-Containing Amino Acids

• Cysteine and methionine contain sulfur
• They contribute to protein structure through disulfide bonds and hydrophobic interactions

Tertiary Protein Structure

• Formed by interactions between the R-groups of amino acids
• Interactions include hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges

Function of a Cofactor

• A cofactor assists enzymes in catalyzing reactions
• It can be a metal ion or an organic molecule (coenzyme)

Polysaccharide Structure

• Polysaccharides are carbohydrates made of many monosaccharides linked by glycosidic bonds
• Examples: starch, cellulose, and glycogen

Enzyme Function

• Enzymes are biological catalysts that speed up chemical reactions by lowering activation energy

Functions of Lipids

• Lipids store energy and provide insulation and structural components of cell membranes

Structural Differences Between Proteins and Lipids

• Proteins are made of amino acids, lipids consist of fatty acids and glycerol
• Proteins have diverse structures (primary, secondary, tertiary, quaternary), lipids have simpler structures
• Proteins contain nitrogen, lipids do not
• Proteins perform various functions, lipids mainly store energy and form membranes

Nucleic Acid Function

• Nucleic acids (DNA and RNA) store and transmit genetic information
• They contain carbon, hydrogen, oxygen, nitrogen, and phosphorus

Nucleotide Polymerization

• Nucleotides polymerize through phosphodiester bonds to form nucleic acids

Amino Acid Structure and Classification

• Amino acids have an amino group, a carboxyl group, and a unique R-group
• Amino acids are classified as nonpolar, polar, acidic, or basic based on their R-groups
• Examples: alanine (nonpolar), serine (polar), aspartic acid (acidic), lysine (basic)

Protein Functions

• Catalysis, transport, structure, immune defense, and movement

Enzyme Function

• Act as biological catalysts to accelerate chemical reactions

Principal Function of Carbohydrates

• Provide energy

Polysaccharides

• Starch: energy storage in plants, cellulose: structural component of plant cell walls

Enzyme Inhibition

• Enzymes can be inhibited by competitive inhibitors (bind to active site)
• Noncompetitive inhibitors (bind elsewhere affecting enzyme shape)

Polysaccharide Linkage

• Glycosidic bonds

Triglyceride vs. Fatty Acid Structure

• Triglycerides consist of a glycerol molecule esterified with three fatty acids
• Fatty acids are long hydrocarbon chains with a carboxyl group at one end

Nucleic Acid Monomer Structure

• Nucleotides consist of a sugar, a phosphate group, and a nitrogenous base

DNA & Genetic Code Relation

• DNA contains the genetic code in the sequence of its bases, which determines protein synthesis

Secondary Protein Structure

• Formed by hydrogen bonds between amino acids, resulting in alpha helices and beta sheets

Locking Key Model

• Enzymes have a specific active site that fits a specific substrate

Chemical Structure of Carbohydrates

• Composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1, forming monosaccharides and polysaccharides

Disaccharides

• Sucrose (glucose + fructose), lactose (glucose + galactose), maltose (glucose + glucose)

R-Group Interactions in Proteins

• Hydrogen bonds, hydrophobic interactions, ionic bonds, and disulfide bridges

Nucleic Acid Functions

• Store and transmit genetic information, involved in protein synthesis

Fatty Acids Structure

• A hydrocarbon chain with a carboxyl group, can be saturated or unsaturated

Lipid Functions

• Store energy, insulate, form cell membranes, hormone signaling

DNA Structure

• Double helix, complementary base pairing (A-T, G-C), deoxyribose-phosphate backbone