101: Lec 14

What makes up the endomembrane system?

Nucleus, ER, golgi, lysosomes

Describe the layers of the nuclear envelope

2 layers, inner and outer. Each is a phospholipid bilayer.

What is at the fused parts of the nuclear envelopes?

Nuclear pores, that allow movement of molecules into/out of the nucleus

Where is rRNA made?

Nucleolus

What is the outer nuclear membrane continuous with?

The membrane of the endoplasmic reticulum

Define the ER

An interconnected network of membrane-enclosed compartments that radiate out from the nucleus

What is the main function of the smooth ER?

Making lipids

What do the SER and RER both make?

Phospholipids for membrane

What are the receiving and releasing ends of golgi apparatus?

Receive at cis face, release at trans face

What enzymes does the golgi contain and where have these been manufactured?

Contains hydrolytic enzymes which have been made in the ER and modified in the golgi

What are the 2 functions of the lysosome?

Digestion of food and facilitate autophagy

What are the functions of the cytoskeleton?

What are the 3 cytoskeletal components?

Microtubules, Microfilaments, Intermediate filaments

What is a common function of the 3 cytoskeletal structures?

Help maintain cell shape

What 2 processes do micro/actin filaments facilitate?

Uptake of food into cell by creating pseudopods and movement of cell

What is the function of intermediate filaments?

Anchoring organelles within the cell

Does cilia or flagellae have a motor?

Flagellae

Do cilia and flagellae have microtubules inside them?

Yes

How do animals cells support themselves (like a structure or something)?

Produce components that form the ECM

What does the ECM contain?

Fibronectin, collagen, proteoglycans

What does fibronectin allow cells to do?

Attach to ECM components so the cell is anchored in the correct position

What are integrins and what are they for?

Transmembrane proteins that can detect changes in ECM components and convey a signal to the inside of the cell to initiate a response

Do saturated or unsaturated fats increase fluidity?

Unsaturated

At what temperatures does cholesterol increase fluidity and how?

Colder temperatures, by preventing phospholipids from packing closely together