Revisison Handout ** Flashcards
Put these forms of bonding in order of strength fro, strongest to weakest?
Covalent bonds
H-bonds
Van der waals forces
List 5 characteristic of living things?
- High degree of complexity
- Use of energy to maintain structure
- Co-ordination
- Sense and response
- Precise self-replication
Put the following structures into size order from lowest to highest ?
1-animal cell
2-bacteria cell
3-nucleus
4-animal ribosomes
5- bacterial ribosomes
There are many ways of speeding up a chemical reaction. For example, higher temperatures and higher concentration of reactants. Why are these two methods not employed in biological systems?
High temperatures - stability of macromolecules is limited
Higher concentration of reactants - costly as more valuable starting material is needed
What two main methods are employed and state two reasons why these are more suited to employment in biological systems ?
Change in reaction by coupling to a fast one
Lower activation barrier by catalysis
Less energy is required, they can occur at body temp.
Besides carbon, name 6 other elements essential to life state which are required in bulk?
BULK
Carbon Hydrogen Oxygen Phosphate Sulphur
potassium K+,,,Sodium NA+,,, Calcium ca++ ARE metal ions
What are the trace elements?
Magnesium mg++
Zinc zn++
Iron fe++
Copper cu
Iodine I
Mag,zinc and iron play important roles in metabolism
Which two trace elements are required in greatest quantity? And why?
Calcium and sulfur
Calcium - is used in bones which are significant components of total body mass also used in ion channels as an electrolyte
Sulfur - is used in amino acid sequences as disulfide bridges giving many proteins their tertiary structure
Water is a good solvent for many biological molecules. It is as close to a universal solvent we can get in biology. However it is not a good solvent for everything,
List 3 things that water is a good solvent for and not good for?
Good
Amino acids
Small alcohols
Carbohydrates
Bad
Non polar gases
Aromatic molecules
Explain hydrogen bonding of water?
Hydrogen bonding occurs when an atom of hydrogen is attracted strong forces of two atoms instead of one acting as a bond between them
Typically hydrogen bonding occurs where the positively charged hydrogen atom lies between negatively charged oxygen and or nitrogen atoms
Hydrogens are vital for life, give examples why?
Source of unique properties of water
- high specific hear capacity
- high cohesion
- high adhesion
Exists in all three states of matter at normal temp
Forms a less dense structure as a solid than liquid (ice floats)
Water is also vital in?
Structure and function of proteins,DNA, polysaccharide,
Binding of sub straights to enzymes
Binding of hormones to receptors
Matching mRNA and tRNA
The hydrophobic effect makes some molecules poorly soluble in water. Explain this effect?
Bulk water has little order has high entropy (not ordered)
Water near a hydrophobic solute is highly ordered (low entropy)
Low entropy is thermodynamically unfavourable
What are the mathematical equations for PKa and ph?
PH=log10[H+]
PKa=log10ka
What would you look for to identify following R groups in aliphatic side chain?
Aliphatic side chain has a long chain of amino acids
What Would you look for to identify the following R groups in basic side chain?
Basic side chain will have positively charged base proton acceptors (+)
What would you look for to identify the following R groups in amino acids acidic side chain?
Acidic side chain - negative charge acids are proton donors
What would you look for to identify the following R groups in amino acids Hydrophobic side chain?
Hydrophobic side chains are long chains with no groups
What would you look for to identify the following R-groups in amino acids hydrogen bonding R group?
Will have an OH
Explain the primary structure?
Amino acid chain with peptide bonds or covalant bonds that are strong and hard to break
No bonding of R groups N and C join in this structure
Denaturing happens here
Explain the secondary structure?
Alpha helix forms organised regular structure ( alpha helixes and beta pleated sheets) in a protein held together by hydrogen bonds NOT Rgroups
Bonding between what’s left of amine and carboxylic acid groups in amino acids
Bonding always between oxygen and nitrogen
Explain the Tertiary structure ?
Tertiary structure is made by Rgroup interactions giving the tertiary structure could be all other type of bonding weaker intramolecullar forces broken easier i.e.
Ionic
Hydrophobic
Polar interactions
Disulphide bonds
Name a fibrous protein and a globular protein?
Collagen = fibrous
Haemoglobin - globular
Explain lock and key?
Active site is the same perfect fit to sub straight, no change in enzyme during binding to sub straight.
Explain induced fit?
Active site changes for a better fit when released it returns to original shape
Enzyme keeps the sub strait under strain
How would you recognise diffusion?
Molecules moving from high to low concentration between phospholipids
Simple diffusion of oxygen + CO2 higher to lower diffusion
How would you recognise facilitated diffusion ?
Molecules moving from high concentration through a protein
It is being helped by proteins on either side
How would you recognise active transport ?
Molecules moving from a low to high concentration thro a protein
The fatty acid oleochemicals acid which is also known as CIS -9-Octadecenoic acid or Z-Octadec-9-enoic acid
What dose the CIS or Z mean in terms of the structure of this fatty acid?
Largest R groups on the same side or equivalent
