Tour of the Cell (1) 2007-2008
Types of cells Prokaryote bacteria cells - no organelles - organelles Eukaryote animal cells Eukaryote plant cells
Cell Size
Why organelles? Specialized structures - specialized functions Containers - partition cell into compartments - create different local environments (separate ph s, or concentration of materials) - distinct and incompatible functions Membranes as sites for chemical reactions - unique combinations of lipids and proteins - embedded enzymes and reaction centers
Cells gotta work to live! What jobs do cells have to do? 1. make proteins proteins control every cell function 2. make energy for daily life for growth 3. make more cells growth repair renewal
Proteins do all the work! DNA proteins cells organism Repeat after me Proteins do all the work!
Cells functions Building proteins - read DNA instructions - build proteins - process proteins folding modifying removing amino acids adding other molecules address and transport proteins
Building Proteins Organelles involved nucleus ribosomes endoplasmic reticulum (ER) Golgi apparatus vesicles nucleus ribosome ER The Protein Assembly Line Golgi apparatus vesicles
Nucleus contains most of cell s DNA Function - protects DNA Structure - nuclear envelope double membrane membrane fused in spots to create pores which allow large macromolecules to pass through nuclear pores nuclear pore nucleolus nuclear envelope
1 nuclear membrane DNA production of mrna from DNA in nucleus Nucleus mrna mrna travels from nucleus to ribosome in cytoplasm through nuclear pore 2 nuclear pore mrna small ribosomal subunit large ribosomal subunit cytoplasm
Nucleolus large subunit small subunit Function ribosome ribosome production build ribosome subunits from rrna and proteins exit through nuclear pores to cytoplasm and combine to form functional ribosomes nucleolus
Ribosomes Function - protein production Structure - rrna and protein large subunit small subunit - 2 subunits combine 0.08µm Ribosomes Rough ER Smooth ER
Types of Ribosomes Free ribosomes - suspended in cytosol - synthesize proteins that function in cytosol Bound ribosomes - attached to endoplasmic reticulum - synthesize proteins for export or for membranes membrane proteins
Endoplasmic Reticulum (ER) little net within the cytoplasm Functions - processes proteins - manufactures membranes - synthesis and hydrolysis of many compounds Structure - membrane connected to nuclear envelope and extends throughout cell
Types of ER rough smooth
Smooth ER functions Many metabolic processes synthesis - synthesize lipids (oils, phospholipids, steroids and sex hormones) hydrolysis - hydrolyze glycogen into glucose (in liver) - detoxify drugs and poisons (alcohol and barbiturates) by adding OH groups, making them more soluble and easier to flush from the body
Rough ER functions produce proteins for export out of cell - secretory proteins are glycoproteins - packaged into transport vesicles for export produce membrane for the cell - builds new membrance - membrane buds off and goes to parts of cell that needs membrane Which cells have lot of rough ER?
Synthesizing proteins cisternal space polypeptide signal sequence mrna ribosome ribosome membrane of endoplasmic reticulum cytoplasm
Golgi Apparatus Structure - consists of flattened sacs (cisternae) with a cis and trans side Function - finishes, sorts, tags and ships cell products - ships products in vesicles secretory vesicles transport vesicles
Golgi Apparatus
Vesicle transport protein vesicle budding from rough ER migrating transport vesicle fusion of vesicle with Golgi apparatus ribosome
Making proteins nucleus nuclear pore cell membrane rough ER protein secreted ribosome vesicle proteins smooth ER cytoplasm transport vesicle Golgi apparatus
nucleus DNA endoplasmic reticulum protein on its way! TO: RNA vesicle TO: ribosomes TO: vesicle Making Proteins Regents Biology protein Golgi apparatus TO: finished protein