Macromolecules Overview Quiz

Macromolecules

• Macromolecules are large organic molecules, primarily carbon-based, forming all living organisms.
• Examples include carbohydrates, lipids, proteins, and nucleic acids.
• Macromolecules are typically polymers assembled from monomers.
• Monomers are small, basic subunits; polymers are large, complex structures composed of monomers.
• Carbohydrates: Primary function is short-term energy storage, also involved in structure, transport, and signaling. Found in sugars and starches; 4 calories/gram.
• Lipids: Primary function is long-term energy storage, also provide insulation, protection, and structural components like phospholipids (cell membranes). Found in fats, oils, phospholipids, and steroids; 9 calories/gram. Phospholipids have a hydrophilic head and hydrophobic tails, forming a bilayer in cell membranes.
• Proteins: Diverse functions (enzymes, hormones, structural components, transport, antibodies, movement, receptors); the most structurally and functionally diverse macromolecule. 4 levels of protein structure (primary, secondary, tertiary, and quaternary); function is determined by its shape. Source of energy in the food we eat.
• Nucleic acids (DNA and RNA): Informational molecules storing and transmitting genetic information required to make proteins. Monomers = nucleotides. Never broken down as an energy source.

Enzymes and Biochemical Reactions

• Enzymes are primarily proteins that accelerate biochemical reactions by lowering activation energy.

• They act as catalysts; not consumed in the reaction and can be reused.

• Enzymes bind to reactants (substrates), aiding in bond breaking/forming, liberating a product.

• Factors affecting reaction rate: temperature, pH, substrate concentration, and catalysts (enzymes).

• Competitive inhibitors slow reactions.

• Key types of chemical reactions include:

  • Endothermic reactions absorb energy (e.g., photosynthesis).
  • Exothermic reactions release energy (e.g., cellular respiration).
  • Metabolic reactions are enzyme-controlled.

Cell Theory and Organelle Structures and Functions

• Cell theory:
  • All living things are made of cells.
  • Cells are the basic units of life.
  • All cells come from pre-existing cells.
• Two cell types: prokaryotic and eukaryotic.
• Unicellular organisms consist of a single cell; multicellular organisms are composed of many cells that form tissues, organs, and organ systems.

Cell Transport

• Two main categories: passive and active transport.

• Passive transport requires no energy input, moving substances down concentration gradients (high to low concentration). E.g. Simple diffusion, facilitated diffusion, osmosis.

• Active transport requires energy (ATP) to move materials against concentration gradients (low to high concentration). Examples include molecular pumps, endocytosis, and exocytosis.

• Simple diffusion: Molecules move from high to low concentration across the membrane until equilibrium is reached. Examples include oxygen and carbon dioxide.

• Facilitated diffusion: Transport proteins aid in molecule movement across the membrane, which are too large to diffuse freely.

• Osmosis: Water movement across cell membranes to equalize water concentration.

  • Hypertonic solution: Higher solute concentration; water moves out of the cell.
  • Hypotonic solution: Lower solute concentration; water moves into the cell.
  • Isotonic solution: Equal solute concentration; no net water movement.

• Molecular pumps: Protein channels that use energy to move molecules against their gradient. Examples include sodium-potassium pumps.

• Endocytosis: Bulk transport of substances into the cell using vesicles. Examples include phagocytosis and pinocytosis.

• Exocytosis: Bulk transport of substances out of the cell using vesicles. Examples include hormone release and neurotransmitter release.

ATP

• Adenosine triphosphate (ATP): A molecule that stores energy for cellular processes.
• ATP structure: Adenine, ribose sugar, and three phosphate groups.
• ATP —> ADP + P + energy (exothermic).
• ADP + P + energy —> ATP (endothermic).

Energy Flow

• Producers (autotrophs): Capture energy from non-living sources (e.g. sunlight) and convert it.
• Consumers (heterotrophs): Obtain their energy by consuming other organisms; herbivores, carnivores, omnivores, detritivores

Photosynthesis and Cellular Respiration

• Photosynthesis: Conversion of light energy into chemical energy (sugars).
• Cellular respiration: Breakdown of sugars to release usable energy (ATP).
• Know the chemical formulas for each
• Know the location of these reactions (chloroplasts and mitochondria). The Electron Transport Chain is a key step in both photosynthesis and cellular respiration, though different names are used in the context of each process.

Cell Cycle

• Cell cycle: Repeated pattern of growth, DNA duplication, and cell division.
• Three main phases:
  • Interphase (growth): G1, S (synthesis), & G2 phases; DNA replication occurs in S.
  • Mitosis (division): Prophase, metaphase, anaphase, telophase.
  • Cytokinesis (cytoplasm separation).

Test your knowledge on macromolecules, the large organic molecules that form all living organisms. This quiz covers the four main types: carbohydrates, lipids, proteins, and nucleic acids. Learn about their structure, functions, and importance in biological systems.