eukaryotes & prokaryotes

Eukaryotes

Greek eu = “true”, karyon = “nut or kernel”; have several membrane-bound organelles and a true nucleus; complex structures need longer cell division (18–24 hrs); include algae, fungi, protozoa, plants, and animals.

Eukaryotic Ribosomes

80S.

Eukaryotic Cell Wall

Present in plant and fungal cells only.

Eukaryotic Cell Processes

Animal cells are capable of pinocytosis and phagocytosis.

Parts of a Eukaryotic Cell

1. Nucleus. 2. Nuclear membrane. 3. Nucleolus. 4. Centrioles. 5. Chloroplasts. 6. Cytoskeleton. 7. Endoplasmic reticulum. 8. Golgi apparatus. 9. Lysosome. 10. Mitochondria. 11. Ribosomes. 12. Vacuoles. 13. Cytoplasm/Protoplasm/Cytosol. 14. Cell wall. 15. Plasma membrane.

Nucleus

Spherical; where chromosomes (DNA) are located; stores genetic information.

Nuclear Membrane

Cell structure that surrounds the nucleus.

Nucleolus

Found within nucleus; contains RNA needed for protein synthesis.

Centrioles

Cylindrical pairs near nucleus, composed of 9 tubes + 3 tubules; involved in cell division.

Chloroplasts

Found in plant cells; contains green chlorophyll.

Cytoskeleton

Composed of microtubules; supports cell shape/structure.

Endoplasmic Reticulum

Cell's transport system; Rough ER has ribosomes while Smooth ER has no ribosomes.

Golgi Apparatus

Near nucleus; numerous layers forming a protein-packaging sac.

Lysosome

Sac-like organelles for removal/transport of undigested materials; digests proteins, lipids, and carbohydrates.

Mitochondria

Second largest organelle; double-layered sac with cristae; energy production; recycles proteins/fats/carbs and forms urea.

Ribosomes

Composed of RNA; 25% of cell mass; site of protein synthesis; stationary in ER or mobile in cytoplasm.

Vacuoles

Membrane-bound sacs for storage, digestion, and waste removal.

Cytoplasm/Protoplasm/Cytosol

Fluid matrix inside the cell, outside the nucleus, where organelles are suspended.

Cell Wall

Complex structure defining shape in fungi, algae, and bacteria; controls turgidity.

Plasma Membrane

Outer membrane; controls cellular traffic; proteins surrounded by a phospholipid layer.

Prokaryotes

Greek pro = “before”, karyon = “nut or kernel”; have a primordial nucleus and simpler morphology; best examples are bacteria and archaea.

Prokaryotic Cell Structure

Bounded by plasma membrane; no other membrane-bound organelles; no true nucleus.

Prokaryotic Cell Division

Can divide into two independent cells in as little as 15 minutes.

Prokaryotic Cell Wall

External to cytoplasmic membrane; contains N-acetyl muramic acid (NAM), a peptidoglycan component.

Prokaryotic Ribosomes

70S.

Prokaryotes and Phagocytosis

Unable to phagocytose.

Prokaryotic Cell Parts

Pilus, capsule, cell wall, plasma membrane, nucleoid (DNA), cytoplasm, ribosomes, flagellum.

Prokaryotic vs Eukaryotic Ribosomes

Prokaryotes = 70S; Eukaryotes = 80S. Eukaryotic mitochondria and chloroplasts still carry 70S ribosomes.