Organelles

PROKARYOTIC CELLS

• Features: 

• 1. Prokaryotic cells do not contain a nucleus or any membrane bound organelles.

• 2. They are always single-celled organisms.

• 3. Very simple structure – cell wall and membrane surrounding cytoplasm.

• 4. Divide by binary fission

• Examples: Bacteria

EUKARYOTIC CELLS

Features:

• 1. Eukaryotic cells contain a nucleus and many membrane-bound organelles.

• 2. Organelle –

  • A structure that performs a specific job inside the cell (think “cell organ”)

• 3. Can be single-celled or multicellular organisms.  

  • Ex. Algae (single) or plants (multi)

• 4. Divide by mitosis

• Examples: Algae, Plants, Animals

Plant Cell:

• Plant Cells have:

  • A square or rectangular shape

  • A cell wall made of cellulose on the outside of the cell

  • A large vacuole for storing water

  • A chloroplast that converts light into sugar for the plant

Animal Cell:

• Animal Cells have:

  • A circular or oval shape

  • No cell wall

  • Can have cilia or flagella for movement if needed

  • Small vacuoles that store water or waste

  • Have centrioles help during cell division

Cytoplasm

• Cells: In all cells

  • Prokaryotic and eukaryotic

• Description: Jelly-like substance inside cells

• Function: holds all cell organelles in place

Mitochondria

• Cells: plant and animal cells (All eukaryotic)

• Description: Large, oval organelles with a double membrane.

• Function:  provide energy for the cell by converting large organic molecules to energy in the process of cellular respiration.

Cell Membrane

• Cell: In both prokaryotic and eukaryotic cells.

• Description: Film surrounding cell

• Function: Controls what enters and exits the cell.

Endoplasmic Reticulum (ER)

• Cell: All eukaryotic

• Description: Series of membranes. Rough ER has ribosomes attached, Smooth ER does not.

• Function: Smooth ER: transport lipids and Rough ER: transport proteins  

  Nucleus

• Cell: Only in eukaryotic cells

• Description: Contains genetic information – DNA

• Function: Control center or “brain,” of cell

• Nuclear envelope (membrane) – membrane that surrounds the nucleus.

• Nucleolus 

  • Description: Dark spot at center of Nucleus 

  • Function:  responsible for making ribosomes.

Golgi Body

• Cells: In all eukaryotic cells (plants & animals)

• Description: Series of flat, membrane-bound sacs

• Function:

  • process the proteins made by the ribosomes

  • package them in vesicles to be secreted out of the cell.

Ribosomes

• Cell: All (Eukaryotic and Prokaryotic)

• Function: Make proteins for the cell. 

• Description: 

  • Eukaryotic cells: float freely or are attached to the endoplasmic reticulum

  • Prokaryotic cells: float freely in cytoplasm

Chloroplasts

• Cells: Only in plant cells (and algae)

• Description: Large, green organelles with a single membrane.

• Function: responsible for making sugar via photosynthesis.

Cell Wall

• Cell: Plant (all fungi and bacteria, algae)

• Description: Rigid wall that surrounds the cell membrane.  

• Function: protects the cells and gives it shape.

Lysosomes

• Cells: In all eukaryotic cells (plants & animals)

• Description: Small, round organelles with a single membrane

• They are digestive organelles.  

• Function: Break down molecules and eliminate waste products.  (“Suicide sac,”)

Vacuoles

• Cells: In all eukaryotic cells (plants & animals)

• Description: 

  • They are also responsible for giving plant cells shape. 

  • Animal cells may have 1 or 2 small vacuoles. 

• Function: Large organelles used for storing water and waste products.  

Centrioles

• Cells: In animal cells

• Description: Small, round organelles used in mitosis

• Function: Creation of spindle fibers to help pull chromosomes apart during mitosis

Vesicles

• Cells: In all eukaryotic cells (plants & animals)

• Description: Parts of the ER and Golgi pinched off

• Located in the cytoplasm 

• Function: Storage bag for proteins

Cytoskeleton

• Cell: In all eukaryotic cells (plants & animals)

• Description: Made of proteins

  • Microfilaments

  • Microtubules

  • Intermediate filaments

• Connects cytoplasm with cell membrane

• Function: Provides structural support and movement

Cilia

• Cells: Animal

• Description: short hair-like projections outside cell

• Function: Movement

Flagella

• Cells: Animal

• Description: long whip like structure outside the cell.  

• Function: Movement