Science Topic 5: Cell & Organelle Functions Flashcards
Cell Theory
All living things are made of cells. The cell is the basic unit of life. All cells come from other cells.
Cytoplasm
Jelly-like substance inside the cell. Holds organelles and is where many chemical reactions happen.
Vesicles
Small sacs that transport or store materials inside the cell or to/from the cell membrane.
Cell Wall
Rigid outer layer found in plant cells, fungi, and bacteria. Provides support and protection.
Prokaryote
Simple, single-celled organisms (e.g., bacteria). No nucleus or membrane-bound organelles.
Cytoskeleton
Network of protein fibers. Provides cell shape, structure, and helps with movement.
Centrioles
Cylinder-shaped structures in animal cells. Help organize cell division by forming spindle fibers.
Cellulose
Tough carbohydrate in plant cell walls. Provides structure and strength.
Archaebacteria
Ancient prokaryotic organisms that live in extreme environments (e.g., hot springs).
Microtubules
Hollow protein tubes in the cytoskeleton. Help with cell shape, transport, and cell division.
Cilia
Short, hair-like structures on the cell surface. Move fluids or the cell itself.
Endoplasmic Reticulum (ER)
Network of membranes that helps with protein and lipid synthesis. Rough ER makes proteins. Smooth ER makes lipids.
Eubacteria
Common bacteria with a cell wall made of peptidoglycan. Found in various environments.
Microfilaments
Thin protein fibers (actin) in the cytoskeleton. Involved in cell movement and shape.
Flagella
Long, whip-like tails that help cells move (e.g., in bacteria and sperm).
Smooth ER / Rough ER
Smooth ER: Makes lipids, detoxifies, stores calcium. Rough ER: Makes proteins (due to ribosomes).
Eukaryote
Organisms with cells that have a nucleus and membrane-bound organelles (e.g., plants, animals).
Lysosome
Small organelles that digest waste and old cell parts. Contain enzymes for breaking down materials.
Mitochondria
Powerhouse of the cell. Converts food into energy (ATP).
Motor Proteins / Kinesins
Proteins that move along microtubules. Transport materials or help with cell movement.
Plasma Membrane
Outer membrane of the cell. Controls what enters and leaves the cell.
Peroxisome
Organelles that break down toxic substances (like hydrogen peroxide).
Chloroplast
Found in plant cells. Converts sunlight into energy (photosynthesis).
Endosymbiotic Theory
Theory that some organelles (e.g., mitochondria, chloroplasts) originated from free-living bacteria.
Organelle
Specialized structures within a cell that perform specific functions (e.g., nucleus, mitochondria).
Golgi Apparatus
Processes and packages proteins and lipids for transport out of the cell.
Ribosome
Small structures that make proteins. Found in the cytoplasm or on the rough ER.
Nucleus
Control center of the cell. Contains DNA and regulates gene expression.
Cell Junctions
Structures that connect cells to each other and help tissues function together.
Plasmodesmata
Channels in plant cell walls that allow communication and transport between cells.
Nuclear Envelope
Double membrane surrounding the nucleus. Controls what enters and exits the nucleus.
Vacuole / Central Vacuole
Storage sacs. Central Vacuole in plant cells stores water, nutrients, and waste.
Nucleolus
Structure inside the nucleus that makes ribosomes.
Chromatin
DNA and proteins in the nucleus. Condenses into chromosomes during cell division.
Chromosome
Organized structure of DNA that carries genetic information.
DNA
The genetic material that carries instructions for growth, function, and reproduction.
