Cell Structure - Ccma
- What is the function of cilia on human cells?
- Move fluid or mucus across the cell surface. Short, hair-like projections beat in coordinated waves to propel substances over epithelial surfaces.
- What is the function of flagella in human biology (sperm cells)?
- Provide cell motility (propulsion). Long, whip-like structures use ATP to generate swimming motion in cells like spermatozoa.
- What is the function of vacuoles in human (animal) cells?
- Small storage compartments for water, ions, or wastes. In animal cells, they maintain osmotic balance and store nutrients or metabolic byproducts.
- Identify the main function of microtubules in the cytoskeleton.
- Intracellular transport and chromosome separation in mitosis. Hollow tubes of tubulin form tracks for motor proteins and organize chromosomes during division.
- What is the primary function of the cytoskeleton in human cells?
- Provides structure, enables movement, and supports transport. Network of filaments maintains shape, facilitates intracellular transport, and enables cell division.
- Which cell structure is the site where most ATP is generated in aerobic cells?
- Mitochondria. Inner membrane cristae house electron transport chain for efficient energy production.
- What is the primary function of vesicles in a cell?
- Transport and store materials within the cell or to the membrane. Membrane-bound sacs shuttle molecules between organelles or to the exterior via exocytosis.
- Which organelle modifies and packages proteins into secretory vesicles?
- Golgi apparatus. Stacked cisternae perform post-translational modifications and sort products for secretion.
- What is the primary function of centrosomes and centrioles?
- Organize microtubules and form the mitotic spindle. Centrioles within serve as microtubule-organizing centers, crucial for spindle formation in cell division.
- Which cell structure is responsible for selective permeability and cell signaling?
- Plasma (cell) membrane. Phospholipid bilayer with receptors enables controlled exchange and communication with environment.
- What is the primary function of smooth endoplasmic reticulum (SER)?
- Lipid synthesis, detoxification, and calcium storage. Lacks ribosomes, specializing in synthesizing lipids and steroids while regulating calcium levels.
- What is the function of lysosomes in human cells?
- Intracellular digestion and recycling of cellular components. Filled with hydrolytic enzymes, they degrade waste and engulfed materials via autophagy or phagocytosis.
- Which organelle contains hydrolytic enzymes for breakdown of macromolecules?
- Lysosome. Acidic interior activates enzymes that digest proteins, lipids, and carbohydrates.
- What is the primary function of the Golgi apparatus?
- Modifies, sorts, and packages proteins and lipids for transport. Receives products from ER, adds modifications like glycosylation, and directs them to destinations.
- Identify the function of ribosomes in human cells.
- Protein synthesis (translation of mRNA into polypeptides). Composed of rRNA and proteins, they decode mRNA to assemble amino acids into proteins.
- Identify the main function of intermediate filaments.
- Provide tensile strength and stabilize cell structure. Resistant to mechanical stress, they anchor organelles and maintain tissue integrity.
- What is the function of the nucleolus inside the nucleus?
- Synthesizes rRNA and assembles ribosomal subunits. Concentrated in rRNA production, it facilitates ribosome biogenesis essential for protein synthesis.
- What is the main function of the nucleus in a eukaryotic cell?
- Stores DNA and directs cellular activities via gene expression. As the control center, it houses genetic material that regulates protein synthesis and cell functions.
- What is the primary function of the plasma (cell) membrane in human cells?
- Selectively controls movement of substances into and out of the cell. Acts as a barrier with embedded proteins that regulate transport, maintaining cellular homeostasis.
- Which cell structure is the site where DNA is transcribed into mRNA?
- Nucleus. Chromatin within unwinds to allow RNA polymerase to transcribe genes into messenger RNA.
- What is the primary function of mitochondria in human cells?
- Produces ATP through aerobic cellular respiration. Contains enzymes for oxidative phosphorylation, converting nutrients into energy currency.
- What is the primary function of rough endoplasmic reticulum (RER)?
- Synthesizes and processes proteins for secretion or membranes. Studded with ribosomes, it folds and modifies nascent proteins destined for export or insertion.
- Identify the main function of microfilaments (actin filaments).
- Cell shape changes, motility, and cytokinesis. Made of actin, they contract to drive muscle movement, cell crawling, and cytoplasmic division.
- What is the function of peroxisomes in human cells?
- Break down fatty acids and detoxify hydrogen peroxide. Enzymes within catalyze oxidation reactions to metabolize lipids and neutralize harmful peroxides.
- What is the primary function of cytoplasm in a human cell?
- Suspends organelles and is the site of many metabolic reactions. Composed of cytosol, it provides a medium for biochemical processes and organelle support.