Cell Structure and Function Quiz

Cell Structure and Function

• Cells are the basic units of life, exhibiting diverse shapes and sizes, specialized for various functions.
• All cells share fundamental features: a cell membrane enclosing cytoplasm containing organelles.
• Prokaryotic cells lack a membrane-bound nucleus and other membrane-bound organelles.
• Eukaryotic cells possess a membrane-bound nucleus and various organelles, enabling compartmentalized cellular processes.
• The cell membrane is a selectively permeable barrier controlling substance passage.
• Cytoplasm is the jelly-like substance filling the cell, housing cellular components.
• The nucleus, typically the largest organelle, holds DNA and controls cell activities.
• Ribosomes synthesize proteins, located free in cytoplasm or bound to the endoplasmic reticulum.
• Endoplasmic reticulum (ER) is a membrane network involved in protein and lipid synthesis, modification, and transport.
• Golgi apparatus modifies, sorts, and packages proteins and lipids for secretion or intracellular use.
• Mitochondria are the cell's powerhouses, performing cellular respiration to produce ATP (energy).
• Vacuoles are membrane-bound sacs involved in storage, transport, and waste removal, especially prominent in plant cells.
• The cytoskeleton provides structural support and facilitates intracellular movement.
• Lysosomes are involved in intracellular digestion and recycling of cellular components.
• Plant cells have unique features: a cell wall, chloroplasts (for photosynthesis), and a large central vacuole.

Biological Molecules

• Biological molecules are essential components of all living organisms.
• Four major classes: carbohydrates, lipids, proteins, and nucleic acids.
• Carbohydrates primarily function for energy storage and structural support.
• Lipids, like fats and oils, store energy, insulate, and form cell membranes.
• Proteins exhibit diverse functions: structural, catalytic, transport, and defense.
• Nucleic acids (DNA and RNA) store and transmit genetic information.
• Monomers combine to form polymers, the building blocks of complex molecules such as proteins.
• Enzymes are biological catalysts accelerating reactions without being consumed.

Cell Processes

• Active and passive transport mechanisms regulate molecule movement across cell membranes.
• Diffusion moves molecules from high to low concentration.
• Osmosis is the passive water movement across a selectively permeable membrane from high to low water concentration.
• Active transport moves molecules against their concentration gradient, requiring energy.
• Cellular respiration releases energy from glucose to produce ATP.
• Photosynthesis converts light energy to chemical energy in plants and some microorganisms.
• Cell division (mitosis and meiosis) ensures growth, repair, and reproduction.
• Mitosis produces two identical daughter cells from a single cell.
• Meiosis produces four genetically diverse daughter cells from a single cell.

Genetics

• DNA is the hereditary material carrying genetic information in the form of genes.
• Genes direct the production of proteins that determine traits.
• The genetic code guides DNA sequence translation into amino acid sequences.
• Mutations are alterations in the DNA sequence.
• DNA replication copies DNA.
• Transcription copies DNA into RNA.
• Translation uses RNA to synthesize proteins.
• Heredity patterns and the principles of inheritance underlie trait transmission.

Ecology

• Ecology studies interactions between organisms and their environment.
• Organisms interact with biotic (living) and abiotic (non-living) environmental factors.
• Ecosystems consist of interacting populations of different species with their environment.
• Energy flows through ecosystems.
• Nutrient cycling occurs within ecosystems.
• Biodiversity encompasses genetic, species, and ecosystem variety on Earth.
• Population dynamics investigate factors affecting population size and growth.