General Biology I - Biomolecules

General Biology I - Biomolecules

• Biomolecules are synthesized by living things. They are molecules with carbon and sustain life. Geological processes cannot create them, but they can move through geological processes.
• Macromolecules are large biological molecules. All living things are composed of carbohydrates, lipids, proteins, and nucleic acids.
• Monomers are the building blocks of biomolecules, single units. Amino acids are monomers of polypeptides (proteins)
• Polymers are complex biomolecules formed from many monomers. Starch is a polymer of glucose.
• Carbohydrates are a major energy source. Examples include bread, pasta, fruit, and vegetables. Monomer is monosaccharide (e.g., glucose).
• Lipids store long-term energy, form cell membranes, and contribute to insulation. Examples include butter or olive oil. Monomers include fatty acids and glycerol.
• Proteins have diverse functions including structure, movement, and defense. Examples include beans, meat, nuts, and eggs. Monomer is amino acid.
• Nucleic acids contain genetic information. DNA and RNA are examples. Monomer is a nucleotide.
• Dehydration/condensation reactions create polymers by removing water molecules. Conversely, hydrolysis breaks down polymers into monomers using water.

General Biology I - Carbohydrates

• Monosaccharides are simple sugars (e.g., glucose, fructose, galactose).
• Disaccharides are formed from two monosaccharides (e.g., sucrose, maltose, lactose)
• Polysaccharides are long chains of monosaccharides (e.g., starch, glycogen, cellulose).
• Cellulose provides structure for plant cell walls, while starch and glycogen are storage forms of glucose.

General Biology I - Lipids

• Lipids are hydrophobic and include triglycerides (fats and oils), phospholipids, and steroids.
• Triglycerides are composed of glycerol and three fatty acids and serve as a major energy storage form.
• Phospholipids are key components of cell membranes, with a hydrophilic head and hydrophobic tails.
• Steroids have diverse functions including hormones and cholesterol.

General Biology I - Proteins

• Proteins are polymers of amino acids.
• There are 20 different amino acids, 11 of which are nonessential and 9 are essential.
• Proteins have diverse functions including structure, movement, defense, catalysis (as enzymes), signaling, and transport.

General Biology I - Nucleic Acids

• Nucleic acids (DNA and RNA) are polymers of nucleotides.
• Each nucleotide has three parts: a phosphate group, a sugar (deoxyribose in DNA or ribose in RNA), and a nitrogenous base.
• The nitrogenous bases are adenine, thymine (in DNA), uracil (in RNA), cytosine, and guanine.

General Biology I - Energy Transformation

• Cells transform energy from one form to another. Photosynthesis converts light energy into chemical energy in the form of glucose, while cellular respiration releases energy from glucose.
• Cellular respiration is a process of releasing energy from glucose that occurs in three stages: glycolysis, the Krebs cycle, and the electron transport chain.

General Biology I - Photosynthesis

• Photosynthesis converts carbon dioxide and water into glucose and oxygen using light energy.
• Key pigments like chlorophyll are crucial in the process.
• Photosynthesis occurs in two parts: light-dependent reactions and light-independent reactions (Calvin cycle).

General Biology I - Cellular Respiration

• Cellular respiration is the process of breaking down glucose to release energy in the form of ATP.
• Three stages of cellular respiration:
• Glycolysis, which takes place in the cytoplasm of a cell.
• Krebs cycle (also called the Citric Acid cycle).
• Electron transport chain (ETC), which takes place in the mitochondria.
• The Krebs cycle and ETC require oxygen.