Organelles

Cell Specialization

Each cell type is specialized to have a specific job in multicellular organisms.

Cell Specialization is controlled by DNA (gene expression).

• Different cell types use (express) different genes to become different.

A cell’s structure (such as shape and contents) determines its function.

In multicellular organisms, cells organize into tissues, organs, and organ systems.

A specific structure is important for each kind of cell as they each have different jobs and their structure matches their job.

Organelles inside each cell are needed to perform various functions for the cell to be efficient (to be able to do multiple things at once).

Three basic parts of All Cells

The three basic parts of all cells are

• plasma membrane

• cytoplasm

• DNA - kept in a specific place

  • Nucleus (eukaryotes)

  • Nucleoid Region (prokaryotes)

Plasma Membrane

also called - cell membrane

made of a phospholipid

• bilayer with proteins inserted in it

Encloses/Surrounds the cell

Selectively Permeable

• only allows certain things in or out

Cytoplasm

A watery semi-fluid (cytosol) area containing organelles

Fills the space between the plasma membrane and nucleus (if there is one)

Cytoplasm is the cytosol AND the organelles

DNA (Genetic information)

DNA exists bound with proteins to form chromosomes

Genes control cellular activities by controlling protein synthesis

Two general cell types

Represent two domains of life

• Prokaryotes

  • prokaryotic cells

• Eukaryotes

  • eukaryotic cells

• Word root karyo

  • means nucleus

Prokaryotic cell structure

No nucleus

• has nucleoid structure instead

• “Pro”

  • pre/before

• “Karyo”

  • nucleus

Simple structure

• NO membrane-enclosed organelles (does have some without membranes)

Most common example: Bacteria Parts of the Prokaryotic Cell

• DNA

  • in nucleoid region

• Cytoplasm

• Plasma membrane

• Ribosomes

• Cell Wall

  • outside of membrane

• Capsul

  • outside of cell wall

Eukaryotic cell structure

Has a nucleus

• “Eu”

  • true

• “Karyo”

  • nucleus

More complex structure

• Has membrane-enclosed organelles (and some without)

Examples: Animals and Plants

Organelles

• a structure that performs a specific function for a cell

  • made of macromolecules

Plasma Membrane (also known as Cell Membrane)

• Function

  • Protect the cell

  • Allows nutrients and other helpful substances into the cell

  • Lets waste products out

• Found in

  • animal cells

  • plant cells

Nucleus

• Function

  • Where genetic information is held

  • Cell’s control center

• Found in

  • animal cells

  • plant cells

Nucleolus

• Function

  • produces and assembles the cell’s ribosomes

  • ribosomal DNA is transcribed here

• Found in

  • animal cells

  • plant cells

Cytoplasm

• Function

  • holds the components of the cell together

  • protects them from danger

• Found in

  • animal cells

  • plant cells

Mitochondria

• Function

  • transform the chemical energy of foods into a form (ATP)

  • ATP can be used for cellular work

    • Mitochondria synthesize energy for the cell, known as ATP

• Found in

  • animal cells

  • plant cells

Rough Endoplasmic Reticulum (RER)

• Function

  • produces proteins for the cell

  • transports them around the cell

• Found in

  • animal cells

  • plant cells

Smooth Endoplasmic Reticulum (SER)

• Function

  • store, transport, and detox things in a cell

  • synthesizes carbs, lipids, and steroid hormones

  • detoxifies toxins and drugs and stores it for later

• Found in

  • animal cells

  • plant cells

Ribosome

• Function

  • synthesizes proteins in a cell

• Found in

  • animal cells

  • plant cells

Golgi Apparatus (Golgi Body)

• Function

  • transporting, modifying, and packaging proteins and lipids into vesicles for delivery to targeted destinations

• Found in

  • animal cells

  • plant cells

Cytoskeleton

• Function

  • helps cells maintain their shape and internal organization

  • provides mechanical support that enables cells to carry out essential functions like division (creation of new cells) and movement

• Found in

  • animal cells

  • plant cells

Lysosome

• Function

  • helps cells in digestion and breaking down waste

  • contains proteins and enzymes within a membrane

• Found in

  • animal cells

Transport Vesicle

• Function

  • help most materials such as proteins and other molecules from one place in the cell to another

• Found in

  • animal cells

  • plant cells

Flagella & Cilia

• Function

  • flagella

    • helps to move an organism from one place to another

    • detect temperature and pH changes

  • Cilia

    • move the cell and move fluids past the cell

• Found in

  • animal cells

Centrioles

• Function

  • arrange chromosomes during mitosis (cell division)

• Found in

  • animal cells

Large Central Vacole

• Function

  • stores water

  • maintains its cell’s turgor pressure

    • pressure exerted by fluid in a cell that presses the cell membrane against the cell wall

• Found in

  • plant cells

Small Vacuole

• Function

  • sequesters waste products

  • hold food/nutrients

• Found in

  • animal cells

Chloroplasts

• Function

  • during photosynthesis processes which oxygen releases

  • make sugar/glucose

  • make active compounds

    • lipids, nucleotides, amino acids, and more

• Found in

  • plant cells

Cell Wall

• Function

  • provides support and structure to the cell

  • surrounds the cell membrane

  • protects the cell from the outside environment

• Found in

  • plant cells

  • probacteria