Vesicles and Vacuoles

Vesicles- membrane- bound sacs found in cells- used to carry many different substances around cells.

Plant cells- large VACUOLE needed to maintain cell stability

• filled with water
• pushes the CYTOPLASM against the cell wall
• TURGID- caused by the water pushing the CYTOPLASM agains the CELL WALL
• Turgidity- helps support the plant

Plant cell walls are:

• Outside of the plant cell plasma membranes
• Plants- made of cellulose- CARBOHYDRATE POLYMER made up of GLUCOSE subunits
• Cellulose- forms a sieve like NETWORK of strands- makes the wall strong
• Held rigid- by PRESSURE of the fluid inside the cell  (turgor pressure)- supports the cell, and effectively the whole plant

• Largest organelle
• When stained- dark patches named CHROMATIN
• Surrounded by a NUCLEUR ENVELOPE
• Has a dense, spherical structure called the NUCLEOLUS inside the nucleus

WHAT IS A NUCLEUR ENVELOPE?

A stucture made of 2 membranes with fluid between them.

Nuclear pores that pass through- relatively large molecules can pass through