Biochemistry Basics Quiz

Biochemistry Basics

• Biochemistry is the study of chemical processes within and relating to living organisms.
• It focuses on the structure, function, and interactions of biomolecules like proteins, carbohydrates, lipids, and nucleic acids.
• Central to biochemistry is the understanding of metabolic pathways, which are series of enzyme-catalyzed reactions that build and break down molecules.

Biomolecules

• Proteins: Composed of amino acids; crucial for structural support, catalysis (enzymes), transport, and signaling.
  • Amino acid structure: Contains an amino group, carboxyl group, side chain (R group).
  • Protein structure: Primary, secondary (alpha-helices, beta-sheets), tertiary, quaternary.
• Carbohydrates: Provide energy and structural support.
  • Simple sugars (monosaccharides): e.g., glucose, fructose.
  • Disaccharides: e.g., sucrose, lactose.
  • Polysaccharides: e.g., starch, glycogen, cellulose.
• Lipids: Diverse group of hydrophobic molecules, including fats, phospholipids, and steroids.
  • Fats: Energy storage, insulation.
  • Phospholipids: Major components of cell membranes.
  • Steroids: e.g., cholesterol, hormones.
• Nucleic acids: DNA and RNA; carry genetic information.
  • DNA: Double helix structure, carries genetic code.
  • RNA: Single-stranded, crucial in protein synthesis.

Metabolism

• Catabolism: Breakdown of complex molecules into simpler ones, releasing energy.
• Anabolism: Building of complex molecules from simpler ones, requiring energy.
• Cellular respiration: Key catabolic pathway, using glucose to produce ATP (energy currency).
• Glycolysis: Initial step in respiration, breaking down glucose.
• Krebs cycle (Citric Acid Cycle): Further breakdown of intermediates.
• Oxidative phosphorylation: Major ATP production via electron transport chain.
• Photosynthesis: Anabolic process, converting light energy into chemical energy (glucose).

Enzymes

• Biological catalysts, speeding up reactions without being consumed.
• Active site: Region where the substrate binds.
• Factors affecting enzyme activity: Temperature, pH, substrate concentration.
• Enzyme specificity: Enzymes typically bind to specific substrates.
• Enzyme inhibition: Competitive and non-competitive inhibition.

Protein Structure and Function

• Primary structure: Sequence of amino acids.
• Secondary structure: Alpha-helices and beta-sheets.
• Tertiary structure: Three-dimensional folding of the polypeptide chain.
• Quaternary structure: Multiple polypeptide chains interacting.
• Protein folding: Crucial for function.
• Protein denaturation: Loss of structure and function due to external factors (heat, pH).

Nucleic Acids Structure

• DNA structure: Double helix with base pairing (A-T, G-C).
• RNA structure: Single-stranded, can fold into diverse shapes.
• DNA replication: Copying of DNA.
• Transcription: Synthesis of RNA from DNA.
• Translation: Synthesis of proteins from mRNA.
• Gene expression: Regulation of gene activity.

Cell Signaling

• Communication between cells and within cells.
• Signaling pathways: Networks of proteins involved in transmitting signals.
• Receptors: Proteins that bind signaling molecules.
• Second messengers: Molecules involved in relaying signals within the cell.

Key Concepts

• Thermodynamics: Energy transformations in biological systems.
• Laws of thermodynamics: Energy conservation and entropy increase.
• Gibbs free energy: Measures spontaneity of reactions.