Reading Guide 6

Nuclear envelope

Double membrane that forms the boundary between the nuclear contents and the cytoplasm; pores

Prokaryotic cells

- No nucleus - No membrane bound organelles

Three main parts of a eukaryotic cell

- Nucleus - Plasma/Cell membrane - Cytoplasm

Eukaryotes and Prokaryotes similarities

- Ribosomes - Cytoplasm - Chromosomes/DNA - Plasma cell membrane

Free ribosomes

- Site if protein synthesis - Suspended in the cytosol - Produces proteins for use within the cell

Bounded ribosomes

- Site of protein synthesis - Attached to the outside of the endoplasmic reticulum - Produces proteins for use outside of the cell or in the cell membrane

Purpose of the endomembrane system

- Synthesizes and transports proteins - Synthesizes lipids - Stores calcium - Detoxifies poisons

Smooth Endoplasmic Reticulum (Smooth ER)

- Synthesizes lipids (including phospholipids and steroids) - Lacks attached ribosomes - Metabolizes carbohydrates - Detoxifies drugs and poisons - Stores calcium ions

Eukaryotic cells

- True nucleus - Nuclear envelope - Membrane bound organelles - Cytosol

Chromatin

Consists of DNA and protein; condenses to form chromosomes

Nucleus

Control center of the cell; contains nucleolus and chromatin

Cell membrane

Controls what goes in and out of the cell, boundary/barrier of the cell

Cytoplasm

Region between nucleus and cell membrane; consists of cytosol