Membranes Flashcards
What are polymers?
Repeated subunits constructing a molecule
How are biological polymers formed?
By the removal of water (dehydration)
Membrane phospholipids are amphipathic molecules - what does this mean?
Have both hydrophobic and hydrophilic parts
What are the main functions of the cellular membrane?
*Compartmentalise metabolic activity
*The separation and protection of cellular components
*Provide a scaffold for signalling
*A medium for cellular energy generation
As size of ? increases, diffusion….
Slows
What is Exocytosis?
(think EXit)
The secretion of large molecules after a vesicle fuses with the plasma membrane
What is Endocytosis?
(think ENter)
The taking in of large molecules when a vesicle is formed
What can generate a small imbalance in ion concentrations?
Diffusion across semi-permeable membranes
A membrane voltage occurs when….
*Immobile charges are not balanced
*Charge transport (of ions) is not fully balanced
What is the purpose of the Nernst Equation?
It is used to describe the equilibrium between chemical and electrical forces on an ion
What happens during Fluorescence Microscopy?
Light is absorbed by a pigment which excites electrons into a higher energy level.
The electron will drop back down to a lower energy level and release energy as light.
What proteins do Aquoria Victoria jellyfish express?
Green Fluorescent Protein
What is the GFP according to wiki?
A protein which exhibits green fluorescence when exposed to light int the blue UV range
Is the endoplasmic reticulum mobile?
Yes, highly
What is the endoplasmic reticulum made of?
Tubules and sacs and is continuous with the nuclear envelope.
What does the smooth ER do?
*Lipid synthesis
*Carb metabolism
*Calcium ion storage
*Detoxification of drugs and poison
What does the rough ER do?
Aids the synthesis of secretory proteins and others on bound ribosomes
What is the Golgi Apparatus structure?
Stacks of flat membranous sacs
What do the cis and trans faces of the Golgi Apparatus mean?
It has polarity
What function occurs in mitochondrion?
Cellular Respiration
Why is molecule transport so important?
For a controlled interaction between the cell and it’s environment
What is the electrochemical gradient?
The net driving force for the movement of a molecule resulting from the combination of the chemical and electrical gradient
What is energy coupling
Transport is coupled to the hydrolysis of ATP
A quick summary of the sodium potassium pump?
- Transporter binds 3 Na+ from inside the cell
- Phosphorylation occurs
- Transporter releases 3 Na+ to the outside and binds 2 K+ from outside of the cell
- Dephosphorylation occurs
- Transporter releases 2 K+ to the inside
What does the sodium potassium pump generate?
A membrane potential
What is an antiport?
When a driver ion and substrate move in the opposite direction
What is a symport?
When a driver ion and substrate move in the same direction
What is transport coupling/co-transport systems?
The coupling of the downward movement of one ion (the driver) to the upward movement of another solute (substrate)
Ions channels are selective and gated, this means they can…?
Exert a tight control of passage
