A Tour of the Cell Unit 2 Chapter 6

Introduction Videos Inner Life of The Cell The Cell High School Biology Inner Life of the Cell (Full Version Narrated)

All cells Have: A plasma membrane (cell membrane) Cytosol (cytoplasm) Chromosomes Ribosomes

Prokaryote Eukaryote No nucleus DNA in nucleoid No organelles Small size Primitive Bacteria & Archaea Has nucleus Membrane-bound organelles larger in size More complex Plant, animal, fungi, protist

Nucleus Contains DNA nuclear envelope: double membrane that surrounds nucleus Continuous with the rough ER Studded with pores Nuclear pores: holes in nuclear envelope Chromatin: complex of DNA + proteins; makes up chromosomes Nucleolus: region where ribosomal subunits are formed

Nucleus Contains DNA Function: control center of cell Surrounded by double membrane (nuclear envelope) Continuous with the rough ER Nuclear pores: control what enters/leaves nucleus Chromatin: complex of DNA + proteins; makes up chromosomes Nucleolus: region where ribosomal subunits are formed

Ribosome Protein synthesis Made of rRNA and protein Constructed in nucleolus Location Free (cytosol) Bound (rough ER)

Endomembrane System Includes: Nuclear envelope Endoplasmic reticulum Golgi apparatus Lysosome Vesicles Vacuoles Plasma membrane

Endoplasmic Reticulum Two parts: Rough ER: Contains ribosomes Continuous with outer nuclear membrane Protein synthesis Smooth ER: Synthesis of lipids (phospholipids, steroids) Carbohydrate metabolism (in liver glycogen to glucose) Detoxifies drugs and poisons (liver enzymes) Storage of Ca ions (muscle contractions)

Golgi Apparatus Parts Functions: Cis Face: products come in Trans Face: products leave Functions: Manufactures certain macromolecules Targets products for various parts of the cell Sorts products for secretion

Lysosomes Sac of hydrolytic enzymes Functions: Diseases: Intracellular digestion (phagocytosis) Recycle cell’s own organic material (autophagy) Programmed cell destruction (apoptosis) Diseases: Pompe’s disease: missing carbohydrase that breaks down glycogen. damages liver Tay-sachs disease: missing lipase causes lipid accumulation in brain

Vacuoles Three Types: Food vacuole Contractile vacuole Central vacuole phagocytosis, fuse with lysosomes Contractile vacuole in freshwater protists, pump excess H2O out of cell Central vacuole Cell sap: main repository of inorganic ions (K,Cl) Cell growth as vacuole absorbs water

Peroxisomes digestive enzyme sacs in both animals & plants breakdown fatty acids to sugars detoxifies alcohol & other poisons produce peroxide (H2O2) oxidases H2 + O2  H2O2 Breakdown of peroxide by catalase 2H2O2  2H 2O +O2