CHAPTER 7 — INSIDE THE CELL

Prokaryotic Cell Similarities

Both have plasma membrane, cytoplasm, ribosomes, DNA

Prokaryotic Nucleus

No nucleus (nucleoid)

Eukaryotic Nucleus

True membrane-bound nucleus

Prokaryotic Organelles

No membrane-bound organelles

Eukaryotic Organelles

Many membrane-bound organelles

Prokaryotic Size

Smaller (1-10 μm)

Eukaryotic Size

Larger (5-100 μm)

Prokaryotic DNA

Circular DNA

Eukaryotic DNA

Linear DNA

Prokaryotic Examples

Bacteria and Archaea

Eukaryotic Examples

Animals, plants, fungi

Nucleus Function

Stores DNA; site of transcription

Ribosome Function

Protein synthesis

Rough ER Function

Makes proteins for export

Smooth ER Function

Makes lipids; detoxification

Golgi Function

Modifies, sorts, and ships proteins

Mitochondria Function

ATP production

Lysosome Function

Digestion of macromolecules

Cytoskeleton Components

Actin, intermediate filaments, microtubules

Actin Function

Muscle movement and cell movement

Intermediate Filaments Function

Form nuclear lamina; provide structure

Microtubules Function

Move chromosomes; form spindle fibers

How Molecules Enter Nucleus

Through nuclear pore complexes

Nuclear Localization Signal (NLS)

"Zip code" that sends proteins into nucleus

What Happens When Protein Gets NLS

It is transported into the nucleus

ER Signal Function

Targets ribosomes to rough ER so proteins enter ER

ER Processing Purpose

Protein folding, glycosylation, and shipping

Three Lysosome Pathways

Receptor-mediated endocytosis, phagocytosis, autophagy

Endosymbiosis Evidence (Mitochondria)

Double membrane; own DNA; own ribosomes; reproduce independently

Endosymbiosis Evidence (Chloroplasts)

Double membrane; own DNA; own ribosomes; reproduce independently