Signal Transduction, ECM and Mitochondria Flashcards
What’s the ECM (Extracellular Matrix)
- Insoluble meshwork composed of proteins and polysaccharides
- For structural support and informational cues
What is the ECM in plants?
-Cell wall
-Mainly composed of cellulose
- Maintain shape, turgor pressure and prevents pathogens from reaching the cell membrane
What are the components of the plant cell wall [3]:
1) Outermost middle lamella
2) Primary cell wall
3) Secondary cell wall
What is the middle lamella?
- Synthesized first
- gluelike carbohydrate
- main mechanism by which plant cells adhere to each other
What’s the primary cell wall?
-Formed second
- Consists mainly of cellulose
- Thin and flexible
What is the secondary cell wall?
-Final thing to be built & not in all plants
- Made of cellulose and lignin
- permits woody plants to grow >300ft
Whats the ECM in animals?
-Generally found in connective tissue
- Consists of large fibrous proteins
Purposes of connective tissue [2]:
1) Physically connects body parts
2) Physically supports other body parts
Role of membrane proteins in signal transduction:
Converting extracellular signals to intracellular signals
What is a ligand
Small molecule that binds to a receptor
Three stages to signal transduction
1) Binding of ligand to receptor
2) Transduction via second messengers
3) Cellular response
Functions of the ECM [4]:
1) Cell adherence
2) Communication between cells
3) Cell shape, support and integrity
4) Barrier, filters out particles
Proteoglycans
proteins with chains of polysaccharides
What is meant by a membrane’s transition temperature?
is the temperature at which a lipid bilayer transitions from a gel-like solid state (where lipids are tightly packed and less fluid) to a more fluid state (where lipids have greater movement and flexibility)
How will the transition temperature of a membrane be affected if the amount of unsaturated lipids is increased?
Increasing the amount of unsaturated lipids will lower the transition temperature.
What property of transmembrane domains allows them to remain embedded in a lipid bilayer?
Transmembrane domains typically consist of hydrophobic amino acids, which interact favorably with the hydrophobic core of the lipid bilayer.
Thinking about the Na+/K+ pump, how many ATP molecules are required to transport 10 K+ ions into a cell?
The Na+/K+ pump transports 2 K+ ions into the cell for every 1 ATP molecule used. To transport 10 K+ ions, the pump would require 5 ATP molecules.
