A network through the cell
The ER begins at the nucleus and spreads outward.
Roads in a city
A city has roads that join every district. A cell also needs routes to make and carry things from place to place.
Where do you think the endoplasmic reticulum starts?
What this lesson covers
The idea
The endoplasmic reticulum (ER) is a network spreading through the cytoplasm, continuous with the outer nuclear membrane, that synthesises and transports proteins, lipids and some hormones.
Roads in a city
A city has roads that join every district. A cell also needs routes to make and carry things from place to place.
Where do you think the endoplasmic reticulum starts?
- Joined to the outer membrane of the nucleus
- At the cell wall
- It floats separately from everything
Trace the ER
Slide to trace the ER outward. Then choose what it makes.
The endoplasmic reticulum
The endoplasmic reticulum (ER) is a large organelle that spreads like a network through the cytoplasm. It is continuous with the outer membrane of the nuclear envelope. It plays a key role in the synthesis and transport of proteins, fats (lipids) and some hormones, in some specialised cells.
The structure of the ER varies with its function. There are two types: rough and smooth.
- Fact | Detail
- Shape | a network spread through the cytoplasm
- Starts at | the outer nuclear membrane (continuous)
- Makes and transports | proteins, fats (lipids), some hormones
Notes
The ER is a network through the cytoplasm, continuous with the outer nuclear membrane. It makes and transports proteins, fats and some hormones.
Check yourself
The ER is continuous with the…
The ER spreads through the cell like…
Which is made and transported by the ER?
What does “continuous with the nuclear membrane” mean?
- outer membrane of the nuclear envelope — correct. Yes.
- cell wall. The wall is outside the membrane.
- vacuole. The vacuole is separate.
- a network — correct. Yes.
- a single ball. It spreads through the cytoplasm.
- a hard shell. It is a network inside the cell.
- Proteins, fats and some hormones — correct. Yes.
- Only water. The ER deals with proteins, lipids and some hormones.
- Sunlight. The ER does not make sunlight.
- The ER and the outer nuclear membrane are joined, with no gap — correct. Yes.
- They are far apart. Continuous means joined.
- They are the same size. It means they are joined.