Chapter 3 - The Cell Flashcards
(21 cards)
Cytoplasm
material between plasma membrane and the nucleus
Cytosol
largely water with dissolved protein, salts, sugars, and other solutes
Cytoplasmic organelles
metabolic machinery of the cell
Mitochondria
Double membrane structure with shelf like cristae
Provide most of the cell’s ATP via aerobic cellular respiration
Contain their own DNA and RNA
Endoplasmic Reticulum
Interconnected tubes and parallel membranes enclosing cisternae
Continuous with the nuclear membrane
Two varieties – rough ER and smooth ER
Golgi Apparatus
Stacked and flattened membranous sacs
Functions in modification, concentration, and packaging of proteins
Lysosomes
Spherical membranous bags containing digestive enzymes
Digest ingested bacteria, viruses, and toxins
Degrade nonfunctional organelles
Peroxisomes
Membranous sacs containing a variety of enzymes
Detoxify harmful or toxic substances
Very numerous in liver and kidney cells
Oxidases and catalases neutralize dangerous free radicals
Free radicals – highly reactive chemicals with unpaired electrons (i.e., O2–)
Look like lysosomes but are self replicating, no Golgi apparatus needed.
Ribosomes
Granules containing protein and rRNA
Site of protein synthesis
Free ribosomes synthesize soluble proteins
Membrane-bound ribosomes synthesize proteins to be incorporated into membranes
Endomembrane System
System of organelles that function to:
Produce, store, and export biological molecules
Degrade potentially harmful substances
System includes:
Nuclear envelope, smooth and rough ER, lysosomes, vacuoles, transport vesicles, Golgi apparatus, and the plasma membrane
Microfilaments
Dynamic strands of the protein actin
Attached to the cytoplasmic side of the plasma membrane
Braces and strengthens the cell surface
Attach to CAMs (cell adhesion molecules), function in cell division, ameboid motion, endocytosis and exocytosis,
Intermediate Filaments
Tough, insoluble proteins
Diameter between that of MF and MT (that’s why they are called Intermediate Filaments)
Look like ropes with high tensile strength
Most stable and permanent
Form internal structure, ie, keratin in epithelials
Microtubules
Dynamic, hollow tubes made of the spherical protein tubulin
Determine the overall shape of the cell and distribution of organelles
Organelles, lysosomes and secretory granules move along the MT by motor proteins
Centrioles
Small barrel-shaped organelles located in the centrosome near the nucleus
Pinwheel array of nine triplets of microtubules
Organize mitotic spindle during mitosis
Form the base of cilia and flagella
Cilia
Whiplike, motile cellular extensions on exposed surfaces of certain cells
Move substances in one direction across cell surfaces
Flagella
Sperm
Nuclear Envelope
Selectively permeable double membrane barrier containing pores
Outer membrane is continuous with the rough ER and is studded with ribosomes
Inner membrane is lined with the nuclear lamina, which maintains the shape of the nucleus
Pore complex regulates transport of large molecules into and out of the nucleus
Nucleoli
Dark-staining spherical bodies within the nucleus
Site of ribosome production
Chromatin
Threadlike strands of DNA and histones
Arranged in fundamental units called nucleosomes
Form condensed, barlike bodies of chromosomes when the nucleus starts to divide
Cell Cycle
Interphase Growth (G1), synthesis (S), growth (G2) Mitotic phase Prophase Metaphase Anaphase Telophase Cytokinesis Biology is the only science in which multiplication means the same thing as division.
Protein Synthesis
DNA serves as master blueprint for protein synthesis
Genes are segments of DNA carrying instructions for a polypeptide chain
