Chapter 3 and 5: Eukaryotes

Cell Membrane

Exterior of cell made of phospholipids and proteins

Cytoplasm

Everything between the nucleus and cell membrane; the organelles, cytosol, and inclusions.

Organelles

Compartments within the cell with specific functions.

Cytosol

Fluid component of cytoplasm, mostly water but with salts, gases, nutrients, etc.

Nucleus

Large organelle with double membrane nuclear envelope

• Nuclear pores

• Genetic Material

  • Linear Chromosomes

Nuclear membrane/envelope

Exterior of nucleus, similar to cell membrane, has nuclear pores (large openings)

Chromatin

Unwound DNA found during all stages of cell cycle BUT mitosis.

Nucleolus

Makes rRNA and assemble ribosomes.

Ribosomes

SYNTHESIZES proteins; free _____ in cytosol, bound ____ on Rough ER.

• Composed of rRNA and proteins.

• Larger than prokaryotic ribosomes (80s)

Rough ER

Has ribosomes on exterior, PROCESSES (or modifies) proteins and sends to Golgi Apparatus.

• Continuous with nuclear envelope.

Golgi Apparatus

PACKAGES proteins in vesicles for secretion, storage, or to become cell membrane.

• Cisternae

  • Stack of flattened sacs

• Modifies, stores, and packages proteins.

• Formation of secretory vesicles

Vesicle

Spherical organelle made of phospholipids and protein, stores molecules.

Lysosome

Digests LARGE molecules, organelles, and cells (bacteria) with enzymes.

• Filled with digestive enzymes formed by Golgi

• Digest foreign substances.

• Autophagy

Peroxisome

Digests SMALL molecules to detoxify the cell and break down fats.

• Contain oxidative enzymes

• Metabolic breakdown of amino acids and fatty acids

• Oxidizes toxic substances

  • Catalase

Smooth ER

Synthesizes lipids and detoxifies the cell.

• Closed tubular network without ribosomes

• Functions in nutrient processing, synthesis, and storage of lipids, detoxification

Mitochondria

Make ATP

• Double-membraned

  • Cristae

    • Hold the enzymes and electron carriers of aerobic respiration

• Divide independently of cell

• Contain circular, ds DNA and 70S ribosomes

Centrosome

Made of 2 centrioles; constructs microtubules which are large cytoskeleton proteins that move organelles, chromosomes during mitosis, cilia, and flagella.

Cilla; microvilli; flagella

Move substances across surface of cell; increase surface are of cell; move entire cell

Chloropasts

Sites of photosynthesis

• Found in algae and plant cells

• Contain circular, ds DNA and 70S ribosomes.

• Double-membraned

  • Outer membrane and inner membrane

  • Internal membrane structures called thylakoids, stacked into grana

Cytoskeleton

Flexible framework of proteins: microfilaments, intermediate filaments, and microtubules form a network throughout the cytoplasm.

• Involved in the movement of cytoplasm, amoeboid movement, transport, anchoring organelles, and structural support.

Microfilaments Dynamic Nature

• Amoeboid movement

• Cytoplasmic streaming

• Contractile ring formation during cytokinesis

• Muscle contraction in animals

Intermediate Filaments

one of a diverse group of cytoskeletal fibers that act as cables within the cell and anchor the nucleus, comprise the nuclear lamina, or contribute to the formation of desmosomes

Microtubules

Hollow, tube-like structures that help maintain the shape of cells and facilitate movement.

Cell Wall

Ridged - provides structural support and shape

• Fungi

• Algae

Fungi Cell Wall

Thick inner layer of polysaccharide fibers composed of chitin or cellulose and a thin layer of mixed glycans.

Algae Cell Wall

Varies in chemical comp.

• Substances commonly found include cellulose, pectin, mannans, silicon dioxide, and calcium carbonate

Cytoplasmic (Cell) membrane

• Typical bilayer of phospholipids and proteins.

• Sterols confer stability

• Selectively permeable barrier in transport

• Membrane-bound organelles in eukaryotes

Eukaryotic Plasma Membrane

Composed of a lipid bilayer with many embedded or associated proteins. It contains cholesterol for the maintenance of membrane, as well as glycoproteins and glycolipids that are important in the recognition other cells or pathogens.

Extra cellular matrix

Non-living complex mix of fibrous proteins and polysaccharides that is secreted by cells.

Functions:

• Supports and anchors cells

• Separate tissues

• Functions in cell signaling

Flagella

Long and single

Cilia

• Unique to eukaryotes

• Short and more numerous

• Feeding and filtering

Genome characteristics

• Multiple chromosomes

• Linear

• Haploid or diploid

• Contains histones

Eukaryotic Microbes

Fungi, Algae, Protozoa, Parasitic Worms