week 2 +3 Flashcards
What is the pH scale
the potential of hydrogen
0-14
what do buffer systems do
absorb excess hydrogen or hydroxide ions
prevent radical change in fluid pH
carbonic acid as weak acid
bicarbonate ion as a weak base
how are macromolecules assembled
dehydration synthesis
carbs
what is a half life
time taken for half the radioactive atom to decay into a more stable form
use for radioasotopes
radioactive iodine for thyroid disease
what is a caoin
positive ion
what is an anion
negative ion
where is ionic bonding found
teeth and bones to give strength to important structural tissues
what does an exergonic reaction do
release energy
what does an endergonic reaction
absorb energy
what is activation energy
the amount of collision energy needed to break a chemical bond
what is polarity
uneven sharing of valence electrons
what is a mixture
the properties
combination of elements or compounds
no chemical bonds
physically blended
what are the 3 types of mixtures
solutions
colloids
suspenstions
what is a solution
solutes evenly distributed
Usually transparent as solute particles are small
what is a suspension
Evenly settles out
e.g blood
blood cells eventually settle out of the suspension and drift to the bottom of the tube
what is a colloid
Larger particles
Particles scatter light
e.g milk with large milk proteins
what do salts do when dissolved in water
dissociate into cations and anions
what is the plasma membrane
selective flexible outer barrier
integral membrane proteins
what are gylocpreoteins
carbohydrate heads that extend into the extracelluar fluid
form extensive sugary coat known as the glyocalyx
integral proteins
what are the function
ion channels
carriers
peripheral membrane proteins
what are these proteins
Not firmly embedded
Attached to lipids or integral proteins
Support + anchor integral proteins
what are the types of transport
2 types
active and passive
what are the passive processes
simple diffusion
facilitated diffusion
osmosis
what is the difference between simple and faciliated difussion
simple = non polar hydrophobic molecules
facilitated diffusion = solutes too polar or highly charged
what are aquaporins
Play a critical role in controlling water component of cells
In the eye aquaporins are responsible to produce tear film and aqueous humor
Mutation of aquaporins have been linked to the formation of cataract
what is tonicity
a measure of the solutions ability to change the volume of cells by altering their water content
define isotonic
concentration of solutes on either side of the membrane are the same
define hypotonic
Solution with a lower conc of solutes than cytosol inside the cell
what is hypertonic
Higher conc of solutes than inside the cell
define osmolarity
total solute conc of a solution
where is glycogen stored
liver and skeletal muscle
what percentage of the body mass is lipids
18-25 %
C H O
what are the 3 types of steroids
cholestrol
estrogen and testosterone
cortisol
what is the use of cholestrol
Maintain cell membrane’s structure
what is the use of estrogen and testosterone
regulating sexual functions
what is the use of cortisol
maintaining blood sugar levels
what % of body mass is proteins
12-18 %
C H O N
structure + function
fibrous protein
isoluble
collogen elastin keratin dystrophin
strucute + function
globular protein
soluble
metabolic functions
enzymes antibodies haemaglobin
what is a cataract
Protein = crystallin in the crystalline lens
Loss of lens transparency
DNA
what are the purines
adenine and guanine
DNA
what are the pyramidines
thymine and cytosine
3 types of RNA
Messenger RNA
Ribosomal RNA
Transfer RNA
