Chapter 15: Protein Transport for Exam 5

all eukaryotic cells

have the same basic set of membrane-enclosed organelles

mitochondrion

ATP production

golgi apparatus

receives and sorts proteins and lipids; can make modifications

receives and sorts lipids and proteins from ER

endoplasm reticulum with membrane-bound ribosomes

synthesis of integral membrane proteins (like transmembrane proteins, etc.)

produces lipids

Ca2+ storage (especially in smooth ER)

endosome

endocytosed material

vesicles that contain variety of material

lysosome

digestive enzymes

peroxisome

breaks down components and can synthesize

oxidative enzymes

evolution of membrane-enclosed organelles

likely began with an expansion of the plasma membrane

internal membranes surround archaeal DNA and aerobic bacterium is fully engulfed

endosymbiont sheds encasing plasma membrane and escapes into cytosol

internal membranes pinch off and form nucleus and elaborate endomembrane system (includes ER, golgi, endosomes, lysosomes)

signal sequences

direct proteins to the correct compartment

proteins are transported into organelles by three mechanisms

gated transport

transmembrane transport

vesicular transport

gated transport

proteins are moved between cytoplasm and nucleus