AP Biology Cell Organelles

Cell Membrane

• Phospholipid bilayer that surrounds cell

• Regulates what comes in and out of the cell

• Protects cell interior

Cell Wall

• Rigid structure made of complex carbohydrates (not found in humans)

• Provides structure to cells and acts as a “permeability barrier for some substances to the internal environment”

Ribosomes

• Found in all living organisms (Common Ancestry)

• Composed of protein and Ribosomal RNA (rRNA)

• Creates proteins by reading messenger RNA (mRNA)

• Can be found… 

  • Attached to Rough ER

  • Free-floating in the cytoplasm

Cytoplasm

• Liquid made of water, salt, and other dissolved nutrients in the cell

• Maintains cell shape of both pro and eukaryotic cells

• Site of many metabolic chemical reactions because it is water based

Cytoskeleton

• Maintains the shape of animal cells

• Parts helps vesicles get transported around the cell

• 3 Parts: Actin, Microtubules, Actin Filaments

Centrioles

Makes spindle fibers during mitosis and meiosis

Spindle Fibers

Helps pull chromosomes apart during mitosis and meiosis

Flagella

Longer and moves like a propeller (Helps move cells around)

Cilia

Shorter and move in a back and forth-beating motion (Helps move cells around)

Nucleus

• Surrounded by double nuclear membrane that stores and protects DNA from denaturation

• Site of transcription (DNA is transcribed into mRNA)

Nucleolus

• Site of ribosome synthesis in the cell

• Creates ribosomal RNA (rRNA)

• Stores DNA

Smooth Endoplasmic Reticulum

• Responsible for lipid/hormone synthesis and detoxification of cell wastes

• Synthesized lipid polymers and hormones get sent to the golgi apparatus

Rough Endoplasmic Reticulum

• Highly folded organelle that is neighboring the nucleus and has ribosomes attached 

• Packages proteins and sends them to the Golgi Apparatus

• Divides the cell into sections

• Has membrane-bound ribosomes that make proteins that leave cell

Golgi Apparatus

• Folds and chemically modifies proteins

• Packages proteins/lipids into vesicles

• Sends these vesicles to their intended intra or extracellular destination

Pathway for Protein Secretion of the Cell

Ribosomes on the Rough ER synthesizes proteins and import them into the Rough ER and helps fold the proteins and tags them for shipment to the Golgi Apparatus. Golgi Apparatus packages proteins into vesicles and are transported to the cell membrane. Vesicles fuse with the cell membrane and allow for secretion of the protein into the extracellular space

Peroxisome

• Responsible for lipid hydrolysis and using catalase (enzyme) to break down hydrogen peroxide (toxic to the cell)

• Lipids are broken down into fatty acid monomers, which are sent to the mitochondrion to help generate ATP

Lysosome

• Lipid bubble containing hydrolytic enzymes (neutral pH) that break down cell waste and denatured proteins into their monomers

• Involved in apoptosis (Programmed cell death)

Vacuole

• Responsible for storing and releasing fluids/biomolecules

  • Store cellular waste products until they can be broken down

• Plants: Very large and helps maintain plant cell shape/turgor pressure

  • Storage of water

• Animals: Very small

Mitochondrion

• Double membrane which allows for compartmentalization of different chemical reactions

  • Outer Mitochondrial Membrane: Smooth, not folded

  • Inner Mitochondrial Membrane: Folding increases surface area to allow for more/faster ATP production

• Has own DNA

• Responsible for some of the processes that synthesizes ATP

  • Citric Acid Cycle (Matrix)

  • Oxidative Phosphorylation (Inner Membrane)

• Uses pyruvic acid to break bonds which releases energy and stores ATP

Chloroplast

• Has double outer membrane which allows for compartmentalization of different chemical reactions

• Internal anatomy is arranged in stacks of thylakoid membranes called grana

• Multiple thylakoids increases surface area so more reactions can occur

• Found in photosynthetic algae and plants

Characteristics of Prokaryotes

• Bacteria and Archaea

• Single Celled Only

• No Nucleus 

• No Membrane Bound Organelles

• Smaller and Simpler Cells

• Oldest Cells

Characteristics of Eukaryotes

• Plants, Animals, Protists, Fungi

• Single celled Or Multicellular

• Have a nucleus

• Have Membrane Bound Organelles

• Larger and more complex cells

• Evolved from Prokaryotic Cells

Shared Characteristics of Prokaryotes and Eukaryotes

• Genetic Material (DNA/RNA)

• Cell Membrane

• Ribosomes

• Cell Walls and Flagella (Only in Some)

• Both Use Cellular Respiration to Make ATP Energy

Non-Membrane Bound Organelles

• Organelles that do not have their own membrane inside of the cell

• Examples: Ribosomes, Cell Membrane, Cell Wall, Cytoplasm

Membrane Bound Organelles

• Organelles that have their own membrane inside of the cell

• Examples: Nucleus, Vacuole, Mitochondria, Chloroplast, Golgi, ER

Where is DNA located in a prokaryote?

Nucleotid

Where is DNA located in a eukaryote?

Nucleus

Free Ribosomes

Makes proteins that stay in the cell

Glycoprotein

• Carbohydrate attached to a protein

• Allows cross linking of cells which gives the tissues strength

Endosymbiosis Theory (Mitochondria and Chloroplast)

• Multiple the same way as bacteria

• Contain own DNA and ribosomes

• Have inner (Contains proteins and lipids) and outer membrane