Bell Work

• Where does cellular respiration take place in the cell?

• Where does photosynthesis take place in the cell?

Biology – Lecture 43

Cell Storage Facilities

Vacuoles

• Storage Bins (bubbles) in the Cells• Large in plant cells, small in animal cells• Plant cell volume depends on the size of the

vacuole.

Vacuoles

• In a factory, vacuoles would be storage facilities

• store food nutrients or water a cell might need to survive

• store waste products so the rest of the cell is protected from contamination

Vacuole Structure

• membrane that surrounds a mass of fluid

In Plants

• When water is scarce, vacuoles are empty and plants droop.

• When water is plentiful, plants stand tall because of the full vacuole.

• They still look like plants because the cell wall holds them up even with empty vacuoles.

Ribosomes

• Make Proteins (enzymes/support for other cell functions)

• Connect one amino acid at a time and build long chains to make proteins

• In a factory, ribosomes are the construction workers.

Where are Ribosomes

• In the cytoplasm (proteins used in the cell)• In the endoplasmic reticulum (proteins used in

the cell and transported outside the cell)

Making Proteins

• mRNA made in the nucleus is sent to the ribsomes

• two subunits come together and lock onto the mRNA to start making the protein by pulling amino acids off of tRNA floating in the cell.

Endoplasmic Reticulum

• The packaging system of the cell• In a factory, it would be the packing center

The Endoplasmic Reticulum

• Works with the Golgi apparatus, ribososmes, RNA, mRNA, and tRNA.

The Endoplasmic Structure

• Rough ER• Has ribosomes attached to it• Looks bumpy

• Smooth ER• No ribosomes• Looks like tubes

Endoplasmic Reticulum

The Purpose of the ER

• Smooth ER - storage organelle• Stores steroids and ions

The Purpose of the ER

• Rough ER - When protein synthesis is completed by ribosomes they are sent to the Rough ER.

• It pinches off a vesicle. • That vesicle (bubble) can move to the cell

membrane or the Golgi apparatus.

The Process

Golgi Apparatus

• (Golgi complex, Golgi Body)• packaging organelle like the endoplasmic

reticulum (ER)

The Golgi’s Job

• Gathers simple molecules and combines them to make molecules that are more complex

• Big molecules are made into vesicles• builds lysosomes (cell digestion machines)• In plants, creates complex sugars and sends

them off in secretory vesicles.

How are Vesicles Created?

• In the same way the ER does it. • The vesicles are pinched off the membranes

and float through the cell.

Working with the ER

• When a protein is made in the ER, so is a transition vesicle is made.

• Vesicles float to the Golgi.• The Golgi uses what it wants, then releases it

with a secretory vesicle back to the cytoplasm.• The vesicle moves to the cell membrane and

the molecules are released out of the cell.

Golgi Apparatus

Golgi Structure

• A series of membranes shaped like pancakes. • The membrane surrounds an area of fluid

where the complex molecules (proteins, sugars, enzymes) are stored and changed.

• Because the Golgi complex absorbs vesicles from the rough ER, you will also find ribosomes inside.