UNIT 2 NOTES:ORGANELLES

(1) Nucleus• Stores DNA / Chromosomes

• Covered in Nuclear Envelope

• Nucleolus makes ribosomes

• “Controls” cell

(2) Endoplasmic Reticulum• Lipid production + assembly

• Protein assembly

• Lipid + Protein export

(3) Ribosome• Protein production

• Works with DNA andRNA

(4) Golgi Body / Apparatus• Modify, Sort & Package Proteins

• Take materials made in endoplasmic reticulum Package to be shipped to other areas of the cell, or to be secreted out of the cell!

(5) Mitochondrion• Convert chemical energy stored in food,

into ATP.

• Undergo Cellular Respiration.

(6) Chloroplast• Convert light energy from the sun,

into stored energy in food.

• Undergo photosynthesis.

(7) Lysosome• Filled with enzymes (Lysozyme) that

digest/break down lipids, carbs, proteins and other molecules into smaller forms.

• Digest “useless” cell parts.

(8) Peroxisome• Contain catalase (enzyme)

• Break down hydrogen peroxide.–H.Peroxide is produced during lipid

metabolism.

(9) Centriole / Centrosome• Centrioles are unique to animal cells.• Centrioles organize DNA during replication

+ division.

• Centrosomes produce microtubules like centrioles.• Centrosomes also help w/division in plant

cells.

(10) Vacuole• Storage sac for materials like water,

salts, proteins and carbohydrates.

• Plants use them to maintain structure.

(11) Cell Membrane• Outer covering on all cells.

• Made of a phospholipid bilayer.

• Controls what enters + leaves the cell.

(12) Cell Wall• More structured outer covering on

some cells.

• Often made of cellulose.

• Provides additional structure + rigidity to cells.

PLANT VS.

ANIMAL CELLS

Animal Cells Only Both Plant Cells

Only•Centrioles

•Only the Cell Membrane on the outside

•Only Mitochondria

•Little tiny vacuoles

•Peroxisomes

•Eukaryotic Cells

•Nucleus

•Ribosomes

•ER

•Golgi Body

•Lysosomes

•Centrosomes

•Cell Wall around the Cell Membrane

•Chloroplasts AND Mitochondria

•Enormous Vacuoles

Endosymbiotic Theory

(1) Endosymbiotic Theory• Modern eukaryotic cells evolved from free-living

prokaryotic cells living symbiotically with larger unicellular organisms.

• Symbiotically??– The cells lived and worked together because they

benefited from the relationship.

(2) Summarizing the Theory• Chloroplasts + Mitochondria were once free-living

bacterial cells (prokaryotes).• The chloroplasts + mitochondria benefited from

living with larger prokaryotes.• The larger prokaryotes took the chloroplasts +

mitochondria inside their cell.

• TA-DA! The Modern Day Eukaryotic Cell

(3) Evidence for the Theory• Chloroplasts, Mitochondria, ….–Have their own fully developed cell membranes.–Have their own copy of DNA.–Can replicate themselves, all on their own.–They have their own ribosomes.–They produce their own proteins.–They can exist/survive on their own w/o a larger

cell.

(4) Other Examples Like This…• Bobtailed Squid + Glowing Bacteria• Aphids + Digestive Bacteria• Spotted Salamander + Algae