Cell Parts & Organelles

1. Cell Wall A) function: physical protection & structural support B) Structure: wall surrounding cell Has holes like windows in a wall C) Macromol. = cellulose

2. Cell Membrane Phospholipids A) function: controls what enters and leaves cell B) Structure: flexible lining just inside cell wall C) Macromol. Phospholipids Proteins

3. Nucleus A) Structure: 1) Nuclear envelope = double layer of membrane around nucleus 2) Nuclear pores = holes in envelope 3) Chromosomes = DNA inside nucleus 4) Nucleolus = area full of ribosome parts

B) Function: Store DNA & direct cell C) Macromol. Phospholipids, proteins Nucleic acids

4.Cytoplasm A) function: every thing that happenes between cell membrane and nucleus B) Structure: 1) all organelles between nucleus and cell membrane 2) all fluid that fills cell = hyaloplasm or cytosol C) Macromol. : all

5. Ribosome 1) Connect amino acids in correct order A) function: make proteins 1) Connect amino acids in correct order 2) Follow directions from RNA B) Structure: 2 subunits 1) Protien subunit 2) RNA subunit C) Macromol. : protein & nucleic acid

6 Mitochondrion 1) Oval outer membrane A- Function: Cellular Respiration 1)Uses O2 to burn glucose & give cell energy 2) O2 + glucose  CO2 and energy B- Structure 1) Oval outer membrane 2) Folded inner membrane Folds called cristae C- Macromolecules: Phospholipids, protein, nucleic acids

7. Chloroplasts 2) CO2 + H2O  Glucose + O2 A- Function: Photosynthesis 1) Converts solar Energy into chemical energy 2) CO2 + H2O  Glucose + O2 B- Structure: 1) Oval outer membrane 2) Grana = stacks of disks C- Macromolecules: Phospholipids, protein, nucleic acids

8. Vacuole A- Function: storage & support (plants) B- Structure: membrane full of water and molecules or food C- Macromolecules: phospholipids

9. Lysosome A- Function: digest food/break down old organelles & macromolecules (hydrolysis) B- Structure: membrane bubble full of enzymes C- Macromolecules phospholipids, proteins (enzymes)

10. Golgi Body A- Function: 1) adds/modifies sugars & lipids on proteins 2) makes complex carbohydrates 3) package for secretion B- Structure: 1) flat membrane pockets, cisternae, filled w/ enzymes C- Macromolecules phospholipids, proteins

11. Rough Endoplasmic Reticulum A- Function: Fold & transport proteins, add carbs to glycoproteins B- Structure: 1) Tunnels made of membrane 2) lots of enzymes 3) ribosomes C- Macromol.: phospholipids, proteins

12. Smooth Endoplasmic Reticulum A- Function: Transport & Detoxify poisons/drugs B- Structure: Membrane tunnels full of enzymes C- Macromol.: phospholipids, proteins

13. Cytoskeleton A- Function: 1) internal mechanical support 2) move organelles & vessicles B- Structure: Framework of microtubules and motor proteins http://www.youtube.com/watch?v=7sRZy9PgPvg C- Macromolecules protein

Cytoskeleton elements (animal & plant) 1) Microtubules – largest; hollow tube shape made of tubulin subunits form spindle & hold organelles in place tracks for motor proteins assembled in area called centrosome can be broken Down and then re-assembled

2) microfilaments – thin strands a. 2 chains of actin subunits twisted into helix b. form cell cortex: mesh of microfilaments at cell membrane give animal cells shape c. amoeboid movement d. muscle cell contraction e. endocytosis/exocytosis f. plant cytoplasmic streaming

3) Intermediate filaments….. yep they are medium size add strength (keratin in hair, nails, dead skin) Highly variable - used to ID cell types

Centrosomes Regions of the cell where tubulin subunits are stored and organized into microtubules Most animal centrosomes contain centrioles Centrioles – 9 triplets of microtubules fused into a short cylinder…helps organize microtubule formation Centrioles lacking in fungi and most plants

Motor Proteins Activated by ATP Conformational changes result in motion Most common: myosins, actins, dynins, kinesins Each type has many variations/versions

Kinesins Walk along microtubules dragging cargo vessicles, organelles,etc. http://www.youtube.com/watch?v=lLxlBB9ZBj4

Dynins Walk along microtubules dragging cargo or bending cilia and flagella

Motor proteins push microtubules past each other Kinesin for mitosis Dynein for cilia motion

Myosin pushes microfilaments past each other To move cell cortex To contract muscle

Prokaryotic Cytoskeleton Poorly developed (mitosis not possible) Some lack cytoskeleton All Eukaryotes have nearly identical genes for tubulin and actin = highly conserved

Cell Junctions Tight Junctions – block things from moving through cracks between cells. Adhering Junctions = desmosomes - anchor cell in place by joining it to its neighbor Gap Junctions = communicating junction – cytoplasmic bridges between cell allow cytosol and small molecules to flow between cells Plasmodesmata = cytoplasmic bridges in plants