Biological Chemistry: Cellular Respiration and Metabolic Pathways

Chemical Composition of Living Beings

Metabolic Pathways

• Series of chemical reactions that occur within a cell to convert energy and nutrients
• Two main types:
  • Catabolic pathways: break down molecules to release energy
  • Anabolic pathways: build molecules to store energy
• Examples: glycolysis, citric acid cycle, pentose phosphate pathway

Cellular Respiration

• Process by which cells generate energy from glucose
• Three stages:
  1. Glycolysis: glucose broken down into pyruvate in the cytoplasm
  2. Citric Acid Cycle (Krebs Cycle): pyruvate converted into ATP, NADH, and FADH2 in the mitochondria
  3. Oxidative Phosphorylation: energy from NADH and FADH2 used to generate ATP in the mitochondria
• ATP (adenosine triphosphate) is the primary energy currency of the cell

Molecular Biology

• Study of the structure and function of biological molecules
• Key molecules:
  • DNA (deoxyribonucleic acid): contains genetic information
  • RNA (ribonucleic acid): involved in protein synthesis and gene regulation
  • Proteins: perform a wide range of functions in the cell
• Central Dogma: DNA → RNA → Protein

Proteins

• Large, complex biomolecules composed of amino acids
• Functions:
  • Enzymes: catalyze chemical reactions
  • Structural: provide structure and support for cells and tissues
  • Transport: transport molecules and ions across cell membranes
  • Regulatory: involved in cell signaling and gene regulation
• Primary, secondary, tertiary, and quaternary structure of proteins

Biochemistry

• Study of the chemical processes that occur within living organisms
• Key areas of focus:
  • Metabolism: study of chemical reactions that occur within cells
  • Enzymology: study of enzymes and their role in catalyzing chemical reactions
  • Nutrition: study of the chemical components of food and their role in maintaining health
• Biochemical reactions: oxidation, reduction, hydrolysis, condensation, etc.

Chemical Composition of Living Beings

Metabolic Pathways

• Metabolic pathways are series of chemical reactions that occur within a cell to convert energy and nutrients
• There are two main types of metabolic pathways: catabolic and anabolic
• Catabolic pathways break down molecules to release energy
• Anabolic pathways build molecules to store energy
• Examples of metabolic pathways include glycolysis, citric acid cycle, and pentose phosphate pathway

Cellular Respiration

• Cellular respiration is the process by which cells generate energy from glucose
• The process of cellular respiration has three stages: glycolysis, citric acid cycle, and oxidative phosphorylation
• Glycolysis is the first stage of cellular respiration, where glucose is broken down into pyruvate in the cytoplasm
• The citric acid cycle (Krebs Cycle) is the second stage, where pyruvate is converted into ATP, NADH, and FADH2 in the mitochondria
• Oxidative phosphorylation is the third stage, where energy from NADH and FADH2 is used to generate ATP in the mitochondria
• ATP (adenosine triphosphate) is the primary energy currency of the cell

Molecular Biology

• Molecular biology is the study of the structure and function of biological molecules
• DNA (deoxyribonucleic acid) contains genetic information
• RNA (ribonucleic acid) is involved in protein synthesis and gene regulation
• Proteins perform a wide range of functions in the cell
• The Central Dogma is the process by which genetic information is passed from DNA to RNA to proteins

Proteins

• Proteins are large, complex biomolecules composed of amino acids
• Proteins can function as enzymes, catalyzing chemical reactions
• Proteins can also have structural roles, providing structure and support for cells and tissues
• Proteins can transport molecules and ions across cell membranes
• Proteins can also be involved in cell signaling and gene regulation
• The primary structure of a protein is the sequence of its amino acids
• The secondary structure of a protein is the arrangement of its amino acids in space
• The tertiary structure of a protein is the 3D shape of the entire protein
• The quaternary structure of a protein is the arrangement of multiple polypeptide chains

Biochemistry

• Biochemistry is the study of the chemical processes that occur within living organisms
• Metabolism is the study of the chemical reactions that occur within cells
• Enzymology is the study of enzymes and their role in catalyzing chemical reactions
• Nutrition is the study of the chemical components of food and their role in maintaining health
• Biochemical reactions include oxidation, reduction, hydrolysis, condensation, and others