Into to biochemistry Flashcards
When are covalent bonds formed?
when unpaired electrons are shared
what is the strongest bond in biomolecules?
covalent bonds
what is an ionic bond?
attraction of opposite charges
what is a hydrophobic interaction?
interaction of non-polar susbstances in the presence of polar substances
what are van der waals interactions?
interaction of electrons of non-polar substances
what is electronegativity?
the attractive force that an atomic nucleus exerts on electrons within a bond
what is phosphorylation?
addition of phosphoryl group
what is dephorphorylation?
removal of a phosphoryl group
what is acylation?
addition of acyl group
what is carboxylation?
addition of a carboxyl group
what is esterification?
occurs between acid and alcohol group producing n ester bond
what is released during esterification?
water
what is a condensation reaction?
where water is removed and molecules are polymerized
what is hydrolysis reaction?
water is added and molecules depolymerize
what happens during redox reactions?
electrons are transferred from one molecule to another
what is oxidation?
loss of electrons
what is reduction?
gain of electrons
what are the functions of biomolecules?
information storage
structural
energy production
energy storage
carbohydrates
communication
what are the 4 major classes of biomolecules?
peptides and proteins
lipids
nucleic acid
carbohydrates
what is glucose called?
monosaccharide
what are 2 glucose joined together or glucose joined with fructose called?
disaccharide
what is cellulose and glycogen called?
polysaccharide
what is the first law of thermodynamics?
energy is neither created nor destroyed - total energy before an dafter is the same
what is the second law of thermodynamics?
when energy is converted from one form to another, some enegry becomes unavailable to do work - no energy transformation is 100% efficient
in what form is energy released during thermodynamics?
carbon dioxide
what happens to the energy released in thermodynamics?
becomes disordered
what do thermodynamic reactions involve change in?
enthalpy and entropy
what is the formula for aclculating change in free energy?
energy of products - energy of reactants
what type of reaction scan occur spontaneously?
exergonic reactions
what is an exergonic reaction?
total free energy of products is less than total free energy of reactants
what is the value of the free energy change in an exergonic reaction?
negative
what type of reaction cannot occur spontaneously?
endergonic reactions
what is an endergonic reaction?
total free energy of products is more than the total free energy of reactants
what do endergonic reactions require?
the input of energy
what is the value of the free energy change in an endergonic reaction?
positive
what is the formula for metabolism?
catabolism + anabolism
what is metabolism?
a;; the reactions taking place in the body
what is catabolism?
the breaking down of larger complex molecules into smaller ones and releasing energy
what is anabolism?
synthesis of large complex molecules out of smaller ones - energy consuming
what is glycolysis?
initial breakdown of glucose for generation of ATP
what is glucogenesis in the anabolic pathway?
the maling of new glucose from non-carbohydrate precursors - costs energy
what are 4 properties of water?
polar
bent
ion
dipole
what type of substances dissolve in water?
ionic and polar substances
what is water described as being?
hydrophilic
what does water tend to exclude?
hydrocarbons
what are hydrocarbons described as being?
non-polar and hydrophobic
what type of bond dooccurs between hydrogen and a more elevctronegative atom?
a polarized bond
what is a hydrogen bond?
hydrogen interacting with unshared electrons from another electronegative atom
what shape do bonds in biomolecules tend to be?
linear
what type of molecules are described as being both hydrophilic and hydrophobic?
amphipathic molecules
what is the structure of amphipathic molecules?
polar head at one end and non-polar tail at the other end
what do amphipathic molecules form in water?
micelles
what is an example of a micelle?
sodium palmitate
what are the 4 classifcations of amino acids?
non-polar
polar
acidic
basic
what do peptide bonds do?
join amino acids
what are peptide bonds produced by?
condensation reactions
what are peptide bonds produced by?
condensation reactions
what are peptide bonds involved in?
the folding of proteins
what are some characteristics of peptide bonds?
partial double bond
planar
strong and rigid
what do acids do?
donate proteins
wat is the strength of an acid dependent on?
how readily is donates a proton
what is the strength of an acid measure by?
dissociation constant Ka
what are bases?
proton acceptors
what is pH a measurement of?
the amount of protons in a solution
what is the Henderson-Hasselbalch equation used for?
calculating the properties of buffer solutions
what is a buffer?
a solution used to control pH of a reaction mixture
when is pH = pKa?
when the concentration of acid is equal to the concentration of the conjugate base
when is pH = pKa?
when the concentration of acid is equal to the concentration of the conjugate base
what can act as buffers?
proteins
what can a change in pH cause?
change in ionisation which changed its structure and function
what is the primary structure of a protein?
the sequence of amino acid which forms a polypeptide chain
what is the secondary structure of a protein?
localised conformation of the polypeptide backbone
how is the secondary structure held together?
hydrogen bonds
what are the 3 types of secondary structures?
alpha helix
beta sheet 1 - parallel or anti-paralel
beta sheet 2 - beta pleated sheets
what is the tertiary structure?
3D structure of entire polypeptide - including all side chains
how are tertiary structures stabalised?
covalent disulphide bonds
electrostatic interactions
hydrophobic interactions
hydrogen bonds
what are 2 examples of tertiary proteins?
fibrous proteins and globular proteins
how cam protein structures be disrupted/denatured?
heat
extremes of pH
detergents
thiol agents and reducing agents
what are quarternary structures?
spartial arrangement of polypeptide chains in a protein with multiple subunits