Biology Macromolecules Quiz

Macromolecules

• Carbohydrates are composed of carbon, hydrogen, and oxygen.
• They are a primary energy source and structural component.
• Types include monosaccharides (simple sugars), disaccharides (two sugars), and polysaccharides (many sugars).
• Examples: glucose, sucrose, starch, and cellulose.
• Lipids are hydrophobic molecules primarily composed of carbon and hydrogen.
• They include fats, oils, phospholipids, and steroids.
• Functions include energy storage, cell membrane components, and hormone production.
• Proteins are complex polymers formed from amino acids.
• Crucial for structural support, enzymatic activity, transport, and defense.
• Different protein structures (primary, secondary, tertiary, quaternary) determine function.
• Nucleic acids include DNA and RNA, encoding genetic information.
• DNA stores genetic information, RNA plays a role in protein synthesis.
• Nucleic acids consist of nucleotides with a nitrogenous base, sugar, and phosphate group.

Cell Structure and Function

• The plasma membrane is the cell's outer boundary, a phospholipid bilayer with embedded proteins.
• It regulates substance passage (selectively permeable).
• Cytoplasm fills the cell, containing organelles and cytosol (fluid portion).
• The nucleus is the control center, housing DNA organized into chromosomes.
• It's surrounded by a nuclear envelope with pores for transport.
• DNA replication and RNA synthesis occur within the nucleus.
• Mitochondria are the "powerhouses" of the cell, sites of cellular respiration producing ATP (energy).
• Mitochondria contain their own DNA.
• Ribosomes synthesize proteins, found in the cytoplasm and on the rough endoplasmic reticulum.
• The endoplasmic reticulum (ER) is a network of membranes.
• Rough ER, studded with ribosomes, is involved in protein synthesis and modification.
• Smooth ER synthesizes lipids and detoxifies substances.
• The Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or internal cell use.
• Lysosomes contain digestive enzymes, breaking down waste and cellular debris.
• Vacuoles are storage sacs, especially prominent in plant cells, often filled with water.
• The cytoskeleton is a network of protein fibers (microtubules, microfilaments, intermediate filaments).
• It provides structural support, facilitates cell movement, and plays a role in intracellular transport.
• The cell wall is a rigid outer layer in plant cells providing structural support and protection.

Cellular Energetics

• ATP (Adenosine Triphosphate) is the cell's primary energy currency, storing energy in phosphate bonds.
• Hydrolysis of ATP releases energy for cellular processes.
• Cellular respiration breaks down glucose to produce ATP.
• It involves glycolysis, the Krebs cycle, and the electron transport chain.
• Photosynthesis is the process where plants and certain organisms use sunlight to synthesize sugars from carbon dioxide and water.
• It occurs in chloroplasts.
• Fermentation is an anaerobic process producing ATP in the absence of oxygen.
• Includes lactic acid and alcoholic fermentation.

Cell Division

• Mitosis results in two genetically identical daughter cells, used for growth, repair, and asexual reproduction.
• It includes prophase, metaphase, anaphase, and telophase.
• Meiosis produces four genetically unique haploid daughter cells, crucial for sexual reproduction.
• It involves two rounds of division (Meiosis I and Meiosis II).
• Crossing over during prophase I increases genetic diversity.
• The cell cycle is the ordered sequence of events from cell formation to division.
• It includes interphase (G1, S, G2) and the mitotic (M) phase.
• Regulation of cell division ensures appropriate rates and only when necessary.
• Mutations in regulatory proteins can lead to uncontrolled cell division (cancer).