A description of the structure and function of some of the organelles

1. Ch 4: The Organelles of
Eukaryotic Cells

2. To aid in your note taking
 Key concepts are underlined
 Vocabulary terms are in green

3. Objectives
1. Identify the parts (in order) and job of
the endomembrane system

4. Why does a cell need all these parts?
 A cell is like a tiny factory that
produces proteins

5. Nucleus
 Contains the
cells DNA
 DNA codes
for proteins
 Controls
most of the
cells
functions

6.  DNA in the form of chromatin – DNA +
proteins

7.  Inside the nucleus is the nucleolus
 Made of RNA + proteins
 Functions in making ribosomes for the cell

8.  The nucleus is surrounded by a membrane
called the nuclear envelope (or nuclear
membrane)
 Small pores (called nuclear pores) in the envelope
allow materials to move in and out of the nucleus

11. Quick check
Identify all components of the nucleus

12. Quick check
Explain: do all cells have a nucleus?

13. Quick check
Use a model: where is this
model is the nucleus?
How can you tell?

15. Ribosomes  Very, very
tiny
 The place
where the
DNA code is
read and
the proteins
are put
together
RNA

16. Ribosomes in a cell

17.  Free ribosomes
 Floating in the cytoplasm
 They make proteins the cell needs
 Bound ribosomes
 Attached to the ER
 They make proteins to be shipped out of the cell

19. Rough Endoplasmic Reticulum
 Sheets of
membrane
covered in
ribosomes

21.  Rough ER
membrane is
connected to the
nuclear
membrane

22.  Proteins that will be shipped out of the cell
are made by ribosomes on the rough ER
 Cells that produce a lot of proteins for export
will have more rough ER

24.  Proteins are sent to the Golgi body in vesicles
that pinch off of the rough ER

25. Quick Check
 It can be difficult to
Distinguish between ER and
Golgi in a cell diagram. Identify at least 2 ways
you can tell the difference between these 2 cell
structures.

26. Quick Think
Suppose you observe a cell with a BUNCH of
bound ribosomes. What could you deduce
from this observation?

27. Quick Think
The nuclear pores of the nuclear envelope allow
molecules into and out of the nucleus. What
are some specific molecules that would need
to get into and out of the nucleus?