Ch. 7 Lecture Notes Flashcards
What is a membrane mainly composed of?
phospholipid bilayer
What happens to bilayers in water?
self assembling in water
Two things Phospholipids are permeable to.
Hydrophobic molecules
Small molecules (including water
Two things phospholipids are impermeable to
Large molecules
ions
What two ways are the phospholipids held in the membrane?
- Their hydrophobic and hydrophilic nature
- Attachment to cytoskeleton
5 Functions of the membrane proteins
1.Emzymes
2. Carry signals
3. Transport
4. Cell recognition
5. Attach membrane to cytoskeleton
What is a way of Passive transport
Diffusion
_____ across a membrane - only occurs
from an area of high to an area of low
concentration.
Does not require energy from the cell
Diffusion
What does the rate of transport during diffusion depend on?
- Temperature
2.Concentration gradient
3.The ability to pass through the membrane
How do materials not permeable to phospholipids pass through proteins?
Facilitated diffusion
How does water pass through the membrane?
Facilitated diffusion
What prevents the passage of water across most biological membranes?
Cholesterols
What allows for the diffusion of water
Osmosis
Water move from an area of:
a) high to low solute
b) low to high solute
b
Term used to describe same salt concentration
Isotonic
Term used to describe a solution with a lower salt concentration
Hypotonic
Term used to describe a solution with a higher salt concentration
Hypertonic
Organisms with cell walls can use what, to give them structure and movement?
Water pressure
What type of transport requires energy
Active transport
What type of energy does active transport require?
Potential
What are the 4 forms of energy important to living things
- Heat
2.Kinetic
3.Potential
4.Light
3 Uses of Energy released from chemical reactions (from bonds)
1.Change the shape of proteins
2.Move molecules
3.Create new bonds
Compound consisting of Adenine, Ribose and a phosphate group
Adenosine Triphosphate
(ATP)
What is released when ATP becomes ADP
Phosphate + Energy
What is added to turn ADP into ATP
Phosphate + Energy
Two types of active transport
1.Transport against a concentration gradient
2.Transport of impermeable substances
How are the two types of active transport accomplished
Membrane bound proteins
What acts as a short term energy storage and transport unit?
ATP
Two processes used to bring large molecules into and out of the cell
Endocytosis and Exocytosis
Cells in exocytosis have what surrounding them?
Golgi bodies
