Cell Structure and Function Quiz

Cell Structure and Function

• Cells are the fundamental units of life, exhibiting diverse sizes and shapes tailored to their functions.
• Prokaryotic cells, lacking a nucleus and membrane-bound organelles, are generally smaller and simpler than eukaryotic cells.
• The plasma membrane controls the passage of substances into and out of the cell.
• Cytoplasm, the semi-fluid substance, surrounds cellular organelles.
• The nucleus houses the cell's DNA, directing cellular activities.
• Ribosomes are the sites of protein synthesis.
• Endoplasmic reticulum (smooth and rough) facilitates the synthesis, processing, and transport of proteins and lipids.
• The Golgi apparatus modifies, sorts, and packages proteins.
• Mitochondria, the powerhouses of the cell, generate ATP via cellular respiration.
• Vacuoles store water, nutrients, and waste products.
• Lysosomes contain enzymes for degrading cellular waste.
• Chloroplasts, found in plant cells, enable photosynthesis.
• Cytoskeleton provides structural support and facilitates cell movement.

Biological Molecules

• Four main classes of biological molecules (carbohydrates, lipids, proteins, nucleic acids) are essential for life.
• Carbohydrates provide energy and structural support.
• Lipids store energy, insulate, and form cell membranes.
• Proteins perform diverse functions including catalysis, transport, and structure.
• Nucleic acids (DNA and RNA) store and transmit genetic information.

Cellular Respiration

• Cellular respiration breaks down glucose to release energy as ATP.
• Key stages include glycolysis, the Krebs cycle, and the electron transport chain.
• Glycolysis occurs in the cytoplasm, producing pyruvate.
• The Krebs cycle occurs in the mitochondria and generates electron carriers (NADH and FADH2).
• The electron transport chain, residing in the inner mitochondrial membrane, generates ATP.
• Aerobic respiration requires oxygen; anaerobic respiration (fermentation) occurs without oxygen.

Photosynthesis

• Photosynthesis converts light energy into chemical energy (glucose) in chloroplasts.
• Photosynthesis takes place within thylakoid membranes within chloroplasts.
• Two main stages are light-dependent reactions (capturing light, producing ATP and NADPH) and light-independent reactions (Calvin cycle, using ATP and NADPH to convert CO2 to glucose).

Cell Division

• Cell division is crucial for growth, repair, and reproduction.
• Mitosis produces two identical diploid daughter cells from a single diploid parent cell.
• Meiosis generates four genetically diverse haploid daughter cells from a single diploid parent cell.
• Mitosis supports growth and repair; meiosis is key to sexual reproduction.

Genetics

• Genes, segments of DNA, code for specific proteins.
• DNA stores genetic information.
• RNA plays a role in protein synthesis.
• Heredity is the transmission of traits from parents to offspring.
• Mutations are DNA sequence changes, leading to variations.

Ecology

• Ecology studies the interactions between organisms and their environment.
• Ecosystems encompass interacting populations and their physical surroundings.
• Biomes are large regions characterized by similar climates and communities.
• Food webs depict the feeding relationships within an ecosystem.
• Energy flows through ecosystems via food chains and food webs.
• Nutrient cycles (e.g., carbon, nitrogen) maintain ecosystem health.

Evolution

• Evolution is the change in heritable traits within biological populations over generations.
• Natural selection favors organisms with beneficial traits for survival and reproduction.
• Adaptation enhances survival and reproduction in a specific environment.
• Common descent suggests all life shares a common ancestor.
• Speciation forms new species.