Tutorial - Week 12/13 - Revision Flashcards
Complete the building blocks for each molecule
Nucleic acids:
- What are the two types?
- What are they polymers of?
- How are nucleotides linked?
- Polynucleotide chains have a ________ at one end and _________ attached to…?
- Which direction are they read?
What are the differences between DNA and RNA? (list the following for both)
- 3D structure
- Sugar
- Bases
- Type
- Function
Amino acids:
- How many standard amino acids are there?
- What do all amino acids have?
- What are they called at physiological pH? What does it mean?
- They are ____________ meaning they contain properties of both _________ and ________
- Are they chiral molecules? What does this mean?
Draw a standard amino acid structure and label the parts
Polymerisation of amino acids:
- What do amino acids polymerise to form?
- What is released during the formation of a peptide bond? What are the two processes called for formation and breaking of a peptide bond?
- What kind of bonds are peptide bonds?
What is the correct nomenclature for this peptide formed at the bottom?
Dipeptide
What is the peptide bond also known as?
T/F: the bond is often written as a single bond?
How many electrons are shared and between which atoms?
What does this sharing of electrons result in?
What is peptide bond resonance?
shared electrons between C-O and C-N
Resonance effect increases stability of the C-N bond, makes it shorter, and decreases rotation around that bond
List the four levels of protein structure and describe each
List the four chemical interactions that stabilise higher levels of
protein structure
What determines the intramolecular bonds within a protein?
The sequence of amino acids (primary structure)
What are intramolecular bonds important for?
These interactions are important to fold the polypeptide chain into a 3D shape, which is essential
to obtain a functional peptide/protein
Fatty acids are…?
- Normally have an _______ number of carbons (___________)
- What kinds of bonds do they have if they are saturated?
- What kinds of bonds do they have if they are unsaturated?
- Unsaturated fatty acids have double bonds in what kind of conformation?
- Some fatty acids are ___________, but cannot be synthesised by ____________ (e.g.?)
- What are free fatty acids and are they common?
What are TAGs also known as?
What are they?
What are they used for?
What are phosphlipids?
What is their nature regarding water?
What are they and what do they do?
What are they components of?
Monosaccharides (_______ sugars)
- What are the three most common monosaccharides in the human diet?
- The common monosaccharides have what kind of structure?
- What is their basic molecular formula?
- Is there a large diversity of them? Why? Explain
- What do these variations in structure result in?
- Monosaccharides are ________ sugars
Label
How do you obtain disaccharides?
Do disaccharides have a reducing end?
Which end is non-reducing?
Describe what bioenergetics is?
How is energy stored in chemicals?
What is the principle molecule for storing and transferring energy in cells?
In Biochemical reactions:
- What is conserved and moved around the reaction?
- What are moved around to obtain different molecules? Does this change anything for the new molecule?
What is the first law of thermodynamics
Living organisms are…?
open systems constantly exchanging material and energy
Living organisms together with their surroundings constitute the _________
universe
What is the second law of thermodynamics?
Cells require sources of ___________ energy
Gibbs free
Gibbs free energy = ?
the energy available to generate work
Cells can and must use ‘____________’, G
Gibbs free energy
Cells obtain Gibbs free energy from?
nutrients (or sunlight)
Cells transform free energy into ______, or _____________
ATP
other energy-rich compounds (1st Law of thermodynamics)
Cells are __________ systems (i.e. _______________)
isothermal
temperature is constant
The Gibbs free energy function predicts the…?
direction of chemical reactions
The Gibbs free energy function predicts the direction of chemical reactions and the amount of…?
work they can perform at constant temperature
Complete - > A + B = ?
the entropy of individual reactions might not increase, but the overall entropy of the ________ increases
universe
When considering the overall system (the ________), cells release to their environment…?
universe
equal amount of energy as
heat and entropy
Reactions are thermodynamically favourable (ΔG < 0 ) if:
- they release energy in the form of heat (ΔH < 0) and/or,
- they increase the disorder of the system (ΔS >0)
What is the driving force behind biochemical reactions? What does it represent the effect of?
ΔG is the driving force in a biochemical reaction, which represents the effect of ΔH and ΔS and at a fixed temperature
Explain each component
T/F: Most reactions are reversible?
True
The direction of the reaction depends on the…? And the following three points which are?
variation of free energy content between reactant and products, ΔG:
- Concentration of each of the molecules in the reaction
- Experimental conditions (e.g. temperature)
- ΔG’0 of the reaction (this is constant to each reaction
What is the result of each of these?
Label as releases or uses energy and give example
Why is a reaction called spontatneous?
The reaction is called spontaneous because it
can occur without the addition of energy
The reaction tends to occur until the ___________ is reached. At equilibrium, the rates of the forward and reverse reactions are equal
equilibrium
ΔG = 0, the reaction is…?
in equilibrium
Nomenclature:
ΔG = ?
is the measured free energy in the reaction. It depends on
experimental conditions
Nomenclature:
ΔG’0 = ?
Explain 4 points
ΔG, ΔG’0 and equilibrium:
- The reaction tends to occur until…?
- The concentrations of A, B, C & D at equilibrium depend on…/
- the equilibrium is reached
- the equilibrium constant of the reaction, Keq
Keq is a constant, characteristic for each reaction
Define the following from the image
ΔG’0 dependent on?
ΔG’0 is dependent on Keq
Complete where the arrows are
Bioenergetics explain…?
how a thermodynamically unfavourable reaction can be driven by coupling with favourable reactions
Complete and label as thermodynamically favourable and unfavourable
A thermodynamically unfavourable reaction can be driven by…?
coupling with favourable reactions
Reaction 1 is coupled with the hydrolysis of ATP; part of the free energy of ATP hydrolysis is used to…?
phosphorylate glucose
Energy coupling in biochemical reactions make reactions…?
thermodynamically favourable
Which reactions are thermodynamically favourable and unfavourable?
In coupled reactions, the ΔG values are ________
additive
ATP hydrolysis coupled with…?
Reactions is a central feature of metabolism
Another very important feature is…?
electron transfer in oxidation-reduction reactions (Redox reactions)
The flow of electrons in oxidation-reduction reactions is responsible, directly or indirectly, for…?
all work done by living organisms
What does electron transfer drives.
Electron transfer drives reduction potentials and supply’s free energy.
The greater the reduction potential the more __________ the free energy and more ___________ the reaction
negative
favourable