AP Bio UNIT 2 - Organelle Functions

Rough ER (Endoplasmic Reticulum)

• “Ribosome assembly line”

• contains ribosomes that create proteins meant for exportation throughout the cell

• many folded membranes to make this efficient

Smooth ER (Endoplasmic Reticulum)

• “Factory for lipids”

• Membrane network inside Eukaryotic cells that synthesizes lipids, phospholipids, and steroid hormones

• Stores & releases calcium

• Metabolizes carbohydrates

Centrosomes

• Made of 2 centrioles - organizing center for animal cells - keeps cell division and structure controlled and stable.

Vacuoles (animal cells)

• “Cellular water pump”

• Actively expels excess water from the cell - powered for ATP

  • Specialized for osmosis regulation - necessary for hypotonic environments
    

Mitochondria

• Generates ATP through oxidative phosphorylation - requires glucose and oxygen

  • Supplies energy to the whole cell

Lysomes

• “Garbage disposal” of the cell

• Breaks down debris - recycles for other processes

  • Also destroys invading pathogens

Golgi Apparatus

• “Logistics HQ”

• Packages, modifies, and transports particles within the cell such as proteins and lipids 

• Transports to both in & outside of the cell (wherever particle final destination is)

• Flat stacked membrane sack w/ compartments for functions

Ribosomes

• “Protein factories” of the cell

• Takes genetic info from DNA and translates it into proteins

  • Reads RNA gene info

  • Links amino acids together

  • Folds polypeptide chains into functional protein

Plasma Membrane

• In both plant & animal cells

• Keeps entire structure of animal cells together (bc no cell wall), allowing for all other organelles to carry out their functions.

• Controls what enters & exits the cell

• Allows for necessary cell functions:

  • Homeostasis

  • Metabolism

  • Cell repair

  • Organelle positioning

Nucleus

• Houses DNA & guides cellular functions (reproduction, metabolism, etc.)

• Controls functions thru gene expression

• Creates RNA by replicating DNA

• Creates & transports enzymes

Vacuole (plant cells)

• Stores water, nutrients, & waste

• Maintains turgor pressure from osmosis

• Supports cell expansion by holding water

  • Can change environment in the cell with stored water

Cell Wall (only in plant cells)

• Gives structural support to plant cells & allows plants to withstand internal water pressure

• Semipermeable to molecules

• Has enzymes for transport & secretion

Chloroplasts

• Help synthesize fatty acids, amino acids, & proteins

• Site of photosynthesis

  • Convert light energy to chemical energy as glucose

Nucleolus

• Primarily responsible for ribosome synthesis

• Largest non-membrane-bound organelle

Vesicles

• Cellular transport pods 

• Transport, store, and release substances

• Often move things between the ER, Golgi, and cell membrane

• Will store waste it finds within the cell

Plasmodesmata

• Channels linking plant cells through their cell walls

• Essential for plant function, transporting water, nutrients, hormones, signals to molecules, development, and results to stimuli