2.2 endomembrane system

name the non membrane bound organelles

• cell membrane

• cell wall

• ribosomes

• cytoplasm

• cytoskeleton

• centriole and spindle fibers

• flagella and cilia 

what is the cell membrane?

• phospholipid bilayer that surrounds the entire cell

• regulates what comes into and out of the cell and protects the cell interior from the extracellular space

what is the cell wall?

• rigid structure made of complex carbohydrates found in plants, fungi and bacteria

• provides structure to cells, as well as acting as a “permeability barrier for some substances to the internal environment.

what are ribosomes?

• found in all living organisms

  • composed of protein and ribosomal RNA (rRNA)

  • Ribosomes “read” messenger RNA (mRNA) to synthesize proteins

• can be found

  • attached to rough ER

  • free floating in the cytoplasm

what is cytoplasm?

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

• helps both Pro and Eu maintain cell shaoe

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

what is the cytoskeleton?

• helps maintain shape of animal cells

• parts of cytoskeleton help vesciles get transported around the cell

• 3 parts: actin, microtubules, actin filaments

explain centriole and spindle fibers

• centrioles make spindle fibers during mitosis and meiosis

• spindle fibers help pull chromosomes apart during mitosis and meiosis

• fun fact: centrioles form the flagellar tail of sperm cells!

what is flagella and cilia?

• both flagella and cilia help move cells around

• flagella are LONGER and move like a propeller

• cilia are much shorter and move in a back and forth-beating motion

name membrane bound organelles

• nucleus

• nucleolus 

• smooth er

• rough er

• golgi

• peroxisomes and lysosomes 

• vacuole

• mitochondrion

• chloroplast

what is the nucleus?

• surrounded by a double nuclear membrane that houses and protects DNA from denaturation

• also the site of transcription which is when DNA is transcribed into mRNA

what is the nucleolus?

• site of ribosome synthesis in the cell

• also responsible for synthesis of ribosomal RNA (rRNA)

what s smooth ER?

• responsible for lipid/hormone synthesis and detoxification of cell waste

• synthesized lipids polymers and hormones get sent to the golgi apparatus

what is rough ER?

• slightly folded (high SA) organelle that is continuous (connected) with the nucleus and has ribosomes attached

• responsible for packaging proteins and sending them to the golgi apparatus

what is the golgi apparatus?

• similar to a post office for the cell

• responsible for

  • helping folded and modify proteins

  • packaging proteins/lipids into vesicles

  • sending these vesicles to their intended intra or extracellular destination

explain protein secretion from the cell

• REGVC (REGular Video Chat)

what are peroxisomes?

• responsible for lipid hydrolysis and also using catalase (an 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

what are lysosomes?

• Lipid bubble full of hydrolytic enzymes that break down cell waste and denatured proteins into their monomers

• Also involved in apoptosis (programmed cell death- if infected by disease or too self, will self destruct)

what is vacuole?

• responsible for storing and releasing fluids/biomolecules

  • also store cellular waste products they can be broken down

• Vacuoles in plants are very, very large and help maintain plant cell shape/turgor pressure

  • storage of water

• Vacuoles in animals are usually very small

what is mitochondrion?

• has 2 membranes, which allows for compartmentalization of diff chemical rxns.

  • outer mitochondrial membrane 

    • smooth, not folded

  • inner mitochondrial membrane

    • folding at inner membrane increase SA to allow for more/faster AT production

• responsible for some of the processes that make ATP

  • citric acid cycle (in matrix)

  • oxidative phosphorylation (on the inner membrane)

what is chloroplast?

• has 2 membranes, which allows for compartmentalization of different chemical reactions

• internal anatomy is arranged in stacks of thylakoids membranes called grana

• multiple thylakoids increases SA so more rxns can occur