A&P1- Module 2: Cells and Chemistry

Free Ribosome

Function:

Polyribosomes represent sites of cytoplasmic protein synthesis

Location:

Cytoplasm

Golgi apparatus

Function:

• Transport vesicles, containing newly synthesized proteins from RER, fuse with cis-face

• Modifies, packages, and sorts newly synthesized proteins

• Modified proteins packaged at trans-face into vesicles that become: lysosomes (contain hydrolytic enzymes), secretory vesicles (undergo exocytosis), or vesicles that add new plasma membrane

Location:

• Cytoplasm

Mitochondrion

Function:

• "Powerhouse" of cell (most cells contain numerous mitochondria)

• Synthesizes adenosine triphosphate (ATP), which provides chemical energy for cellular respiration (through oxidative phosphorylation)

Location:

• Cytoplasm

Nucleolus

Function:

• Ribosomal RNA synthesis and ribosome assembly

Location:

• Nucleus

Nucleus

Function:

• DNA replication

• DNA transcription into mRNA

• Ribosomal RNA synthesis and ribosome subunit assembly (in nucleolus

Plasma Membrane

Function:

• Encloses cell contents

• Communication (receptors)

• Intercellular connections

• Regulates movement of materials into and out of cell

Location:

• Cell surface

Rough Endoplasmic Reticulum

Function:

• Synthesizes protein for secretion, insertion into plasma membrane, and lysosomal enzymes and other proteins packaged in vesicles

Location:

• Cytoplasm (perinuclear)

• Between nucleus and Golgi apparatus

Smooth Endoplasmic Reticulum

Function:

• Synthesizes lipids (especially membrane phospholipids)

• Detoxifies drugs and alcohol

• Metabolizes carbohydrates

• Stores calcium (i.e., in sarcoplasmic reticulum)

Location:

• Cytoplasm