Lecture 6 Flashcards
What are the key things that a cell does?
Manufacture cellular materials (i.e proteins, nucleic acids)
Obtain raw materials
Generate energy
Remove wastes
What do organelles allow for?
Special conditions for specific processes
Keep incompatible processes apart
Allow for high concentrations of substances
Form concentration graidents
Package for transport or export
What is the definition of a membrane?
A semi-permeable barrier to control movement of substances.
What are the order of structures in the membrane?
Hydrophilic phosphate groups
Fatty acids (hydrophobic)
Hydrophilic phosphate groups
What is the purpose of Cholesterol within the membrane?
To affect the fluidity of the membrane.
What happens to the fluidity of the membrane at moderate temperatures?
Reduction of fluidity
What happens to the fluidity of the membrane at low temperatures?
Increases of fluidity
What does saturated fatty acids mean? What does this mean for packing?
It means that there are all single bonds within the molecules. This means that they are able to pack more closely.
What types of molecules are permeable in passive transport?
Lipid soluble molecules.
What types of molecules are not permeable in passive transport?
Water soluble molecules and charged molecules
What types of molecules do facilitated diffusion move?
Hydrophilic molecules
What are the two types of active transport?
Indirect and Direct
What is indirect active transport?
The use of energy to create a gradient so that the ion or molecule of interest is transporter indirectly.
What is direct active transport?
The energy that is needed is used to change the membrane protein shape in order to transport the ion/molecule across.
What does it mean when membrane proteins give the cell its’ character?
It means that the varying the amount and types of membrane proteins cells have make them uniques to one another.
