Eukaryotic Cell Structure and Function

Eukaryotic Microorganisms

Key members of ecosystems and human pathogens.

Protists

Diverse group of eukaryotic microorganisms.

Fungi

Eukaryotes with cell walls made of chitin.

Ostreococcus tauri

Smallest free-living alga at 0.8 μm.

Plasma Membrane

Lipid bilayer surrounding eukaryotic cells.

Glycocalyx

Carbohydrate-rich layer on cell surface.

Cell Wall

Rigid structure in fungi and some protists.

Plasmalemma

Cell membrane of protists.

Pellicle

Protective layer providing shape in protists.

Ectoplasm

Outer gelatinous region of cytoplasm.

Endoplasm

Inner fluid region of cytoplasm.

Cytoskeleton

Network of filaments providing cell structure.

Microfilaments

Actin filaments involved in cell movement.

Intermediate Filaments

Structural elements linking cells and organelles.

Microtubules

Cylindrical structures aiding in transport and support.

Endoplasmic Reticulum (ER)

Network of membranes for protein and lipid synthesis.

Rough ER

ER with ribosomes for protein synthesis.

Smooth ER

ER without ribosomes, synthesizes lipids.

Golgi Apparatus

Organelle for modifying and packaging proteins.

Endocytosis

Process of bringing materials into the cell.

Phagocytosis

Engulfing particles using cell surface protrusions.

Autophagy

Digestion of cytoplasmic components without endocytosis.

Lysosomes

Digestive organelles containing hydrolytic enzymes.

Secretory Pathways

Routes for moving materials to cell exterior.

Nucleus

Membrane-bound structure housing genetic material.

Nuclear Envelope

Double membrane surrounding the nucleus.

Nucleolus

Ribosome synthesis site within the nucleus.

Eukaryotic Ribosomes

80S ribosomes involved in protein synthesis.

Mitochondria

•“Powerhouses” of most eukaryotic cells

•Site of tricarboxylic acid cycle activity

•Site where ATP is generated

•About the same size as bacterial cells

•Reproduce by binary fission as do bacterial cells

Chloroplasts

Organelles for photosynthesis in plants and algae.

Cilia

Short, hair-like structures for cell movement.

Flagella

Long, whip-like structures for cell propulsion.

Axoneme

Core structure of cilia and flagella.

Basal Body

Structure directing synthesis of cilia and flagella.