The cell nucleus ● All living cells contain a nucleus; some animal cells, like muscle cells, may have two. ● The nucleus is the ‘brain’ of the cell.

1. The cell nucleus
● All living cells contain a nucleus; some animal cells, like muscle cells, may
have
two.
● The nucleus is the ‘brain’ of the cell.
● Functions of the nucleus:
● controls how and which proteins and enzymes are made
● when the cell will divide.

2. Endoplasmic reticulum
• ● The endoplasmic reticulum is closely linked to the nucleus:
• ● smooth endoplasmic reticulum (SER) – a network of membranous
tubes
• ● rough endoplasmic reticulum (RER) – a network of tubes with
ribosomes
• attached.

3. Functions of the endoplasmic reticulum:
• ● Connects the cell membrane and nucleus membrane.
• ● SER and RER connect to the cell membrane to transport
substances.
• ● RER and ribosomes make proteins for transport.

4. •Structure
• Double nuclear membrane
• Function
• Encloses and protects chromatin network