Membranes Flashcards
Polar molecule
Has positive and negative charges
How many micrometers (um) in one meter?
1000000
How many nanometers in one metre
1000000000
How many picometers in one metre
1000000000000
What is bigger: a virus or a bacterium?
Virus
Why are some molecules water soluble?
They are made up of elements of slight positive/ negative charges which attract ions that then become soluble.
What are phospholipids
Fatty acids
What does the length of a hydrocarbon chain affect? (And e.g.s) e.g in phospholipids.
Fluidity; e.g shorter = more fluidity, longer =less fluidity
What does cholesterol do
Provides stability and thickness to membranes. Ie, hotter temperatures mean particles move quicker in the membrane so substances are lost more easily. Cholesterol reduces this.
Describe a phospholipid
Phosphate head- has a charge and therefore is hydrophilic.
The tail doesn’t have a charge so therefore is hydrophobic.
Where are peripheral membrane proteins found
The sirface of a membrane
What are the properties of transmembrane proteins related to water and charges.
They have a charge on the outside which allows water across as it’s hydrophilic. (From the outside).
They are insoluble in water
Name the other two transmembrane proteins beginning with g
Glycoproteins and glycolipids
Transcription and translation proscess
- DNA unwinds and hydrogen bonds break (to allow unwinding)
- Complimentary nucleotide base pairing (A to T, C to G)
- mRNA; all non coding regions removed, one triplet code = one amino acid
Name the 6 types of diffusion
Vesicles (entry= endocytosis, exit = exocytosis).
Lipid diffusion
Co transport
Facilitated diffusion
Active transport
Osmosis
5 factors that affect diffusion
Temperature
Surface area
Concentration
Number of proteins
Particle size
Facilitated diffusion definition
Diffusion down a concentration gradient with the help of a channel/ carrier protein
Why is lipid diffusion different from active transport? (3) ON,Y HALF EXPLANATIONS)
Across phospholipids
Polar molecules (lipids)
Down a concentration gradient
Solute
Substance that can dissolve in another substance (solvent).
Solvent
Substance that the solute dissolves in
Soluble
Substance that can dissolve; has double bonds
Osmosis
The passive movement of water molecules across a partially permeable membrane from an area of high concentration to low.
Water potential (negative); def + what it’s measured in.
Measure of potential of a solution to absorb more water molecules.
Kilopascals, kPa, (looks like the religious candle symbol thing)
Hypertonic
Plasmolysis
Hypotonic
Cytolysks
Isotonic
No net movement
