Eukaryotic Cell Structures (Page 98)

Nucleus Picture

Nucleus Picture

Nucleus Structure

Surrounded by an envelope (double membrane) that is perforated with pores and continuous with the endoplasmic reticulum.

Nucleus Function

Houses chromosomes, which are made of chromatin (DNA and proteins); contains a structure that creates ribosomal sub-units

Ribosome Picture

Ribosome Structure

Two sub-units made of RNA and proteins; can be free in the cytosol or bound to ER

Ribosome Function

Protein Synthesis

Smooth Endoplasmic Reticulum Picture

Endoplasmic Reticulum Structure

Extensive network of membrane bound tubes and sacs, membrane that separates lumen from cytosol; continuous with nuclear envelope

Smooth Endoplasmic Reticulum Function

Synthesis of lipids, metabolism of carbohydrates, Ca2+ storage, detoxification of drugs and poisons

Rough Endoplasmic Reticulum Picture

Rough Endoplasmic Reticulum Function

Aids in synthesis of secretory and other proteins from bound ribosomes; adds carbohydrates to proteins to make glycoproteins; produces new membranes

Golgi apparatus Picture

Golgi apparatus Structure

Stacks of flattened membranous sacs; has polarity

Golgi apparatus Function

Modification of proteins, carbohydrates on proteins, and phospholipids. Synthesis of many polysaccharides and sorting of products, which are then released in vesicles.

Lysosome, Peroxisome, or Vesicle Picture

Lysosome Structure

Membranous sacs of hydrolytic enzymes (found in animal cells)

Lysosome Function

Breakdown of ingested substances, cell macromolecules, and damaged organelles for recycling

Vacuole Picture

Vacuole Structure

Large membrane-bound vesicle

Vacuole Function

Digestion, storage, waste disposal, water balance, plant cell growth and protection

Mitochondria Picture

Mitochondria Structure

Bounded by double membrane; inner membrane has infoldings (christae)

Mitochondria Function

Cellular respiration

Chloroplast

Chloroplast Structure

Typically two membranes around fluid stroma, which contains thylakoids stacked into grana (in cells of photosynthetic eukaryotes, including plants)

Chloroplast Function

Photosynthesis

Peroxisome Picture

Peroxisome Structure

Specialized metabolic compartment bounded by a single membrane

Peroxisome Function

Contains enzymes that transfer hydrogen atoms from certain molecules to oxygen, producing hydrogen peroxide (H2O2) as a by-product; H2O2 is converted to water by another enzyme

Alternate Nucleus Function

Alternate: Stores the genetic material

Alternate Ribosome Function

Alternate: Arranges and links amino acids to form polypeptides

Alternate Lysosome Function

Alternate: Hydrolysis of materials

Alternate Vacuole Structure

Alternate: Plant cells often contain a single large one of these

Alternate Mitochondrion Function

Alternate: Breaks down food to release energy and make ATP

Alternate Chloroplast Function

Alternate: Uses sunlight to combine carbon dioxide and water to make sugar!