Definition of monomer
Small units from which larger molecules are made
Definition of polymer
Lots of monomers joined together
3 Examples of monomer
Monosaccharides
Amino acids
Nucleotides
What is condensation
Joining 2 molecules releases water
What is hydrolysis
Breaking 2 molecules apart by adding water
4 examples of monosaccharides
Alpha glucose
Beta glucose
Galactose
Fructose
Difference between beta glucose and alpha glucose
Alpha
Hydrogen above
Beta
Hydrogen below
Name 3 Disaccharides
Lactose
Maltose
Sucrose
What makes
Lactose
Maltose
Sucrose
Lactose= glucose+galactose
Maltose= alpha glucose x2
Sucrose = glucose + fructose
What is the bond made between saccharides
Glycosidic bond
Name 3 polysaccharides
Starch
Glycogen
Cellulose
Starch
Monomer?
Structure?
Relate to function?
Alpha glucose
Highly branched/ helix
Storage of glucose in plants
Compact takes up less storage
Insoluble- doesn’t affect water potential
Glycogen
Monomer
Structure
Relates to function
Alpha glucose
Highly branched
Storage of glucose in body
Compact takes up less space
Insoluble
Cellulose
Monomer
Structure
Relates to function
Beta glucose
Straight, unbranched chains
Provides rigidity to plant cells
Strength because of hydrogen bonds holding the fibrils together
Biochemical test
Reducing sugar
Add Benedict reagent
Positive test if turns Orange / brown
Biochemical test
Test for non-reducing sugars
Add HCl - hydrolysis it
Add sodium hydrogencarbonate- to neutralise
Add Benedict reagent
Positive if turns orange / brown
Biochemical test
Test for starch
Add iodine
Make blue-black
What is in a phospholipid?
x2 fatty acids
x1 glycerol
x1 phosphate group
What is in a triglyceride ?
x3 fatty acids
x1 glyceride
Polar or non-polar
Phospholipid?
Triglyceride?
Polar
Non-polar
Roles of lipids
- source of energy
- waterproofing
- insulation
- protection
Phospholipid structure properties
What they can form
Hydrophilic head-to water
Hydrophobic tail- away water
Form phospholipid bilayer
For cell recognition
Triglyceride properties
- high ratio of H-C so a lot of energy
- insoluble doesn’t affect water potential
- high ratio of H-O when oxidised makes water
Biochemical test
Test for lipids
Emulsion test
Add ethanol
Add water
Cloudy-white colour = positive result
What does saturated mean ?
No double bonds
What does unsaturated mean ?
Double bonds present
Structure of a amino acid
H H OH \ | / N- C - C / | \\ H R O
Which part of the structure is the amino group?
H \ N / H
Which part of the group is carboxyl group ?
OH / C \\ O
What is the polymer of a protein called
Polypeptide
What is the bond between amino acids
Peptide bond
Explain primary structure
Polypeptide chains
If one amino acid changes so will the whole function
Explain secondary structure
Hydrogen bonds are formed
= 3D shape
E.g. A alpha helix or beta pleated sheet
Explain tertiary structure
Interaction of E groups =more hydrogen bonds =disulphide bridges = covalent bonds =ionic bonds
Becomes more twisted
Explain Quartenary structure
Add prosthetic groups
More chains
Explain globular proteins
Common
Soluble
Spherical
Carry out metabolic function
E.g. Antibodies and enzymes
Explain fibrous proteins
Long chains Run parallel Joined by cross bridges In soluble Linked with hydrogen bonds and disulphide bridges
E.g. Collagen , keratin
Biochemical test
Protein
Add biuret reagent
Changed to purple/ lilac colour
What type of protein and level of structure are enzymes?
Globular protein
Tertiary structure
Explain lock and key model
Active site complimentary to substrate
Bind together makes an enzyme- substrate complex
What does the lock and key model not explain
The flexible structure of enzymes
How activation energy is lowered
Explain the induced fit model
Active site and substrate are not fully complimentary
Bind together to make enzyme substrate complex
Active site changes shape slightly which puts strain on substrate
Lowers the activation energy
What is the effect of pH on enzymes
Enzymes have an optimum pH
Changes in pH distorts enzyme
What is the effect of substrate concentration on enzymes
As concentration increases there are more successful collisions eventually becomes a plateau because enzymes are a limiting factor
What is a competitive inhibitor
Have molecular structure similar to substrate therefore can occupy the active site
Explain non-competitive inhibitors
Attach themselves to anything but active site.
This denatures the enzyme by changing its shape and this means can longer be used
What is a nucleotide
A monomer of DNA
Structure of deoxyribose
Phosphate groups
\
Pentose sugar -nitrogenous baseball
Structure of DNA
Double helix Antiparallel Form phosphodiester bonds Hydrogen bonds between bases Complimentary pairs
What are the complimentary base pairs
Adenine and thymine
Cytosine and guanine
How many hydrogen bonds between
Adenine and thymine
Cytosine and guanine
2 hydrogen bonds
3 hydrogen bonds
What type of molecule is water
Dipolar
What are 4 properties of water
High specific heat capacity
Latent heat of vaporisation
Cohesion and surface tension
Important to organisms
Explain the high specific heat capacity of water
Had a high specific heat capacity
Stops sudden changes in environment which is good for aquatic environment.
Explain latent heat of vaporisation for water
When water evaporates it takes energy with it providing a cooling effect
So there will be little loss of water and can still stay cool
Explain cohesion and surface tension in water
Allows thin columns of water to be pulled up towards leaves through xylem vessel
Explain waters importance to organisms
Used in metabolism
- hydrolysis and condensation reactions
As a solvent
- dissolve a lot of substances
4 requirements for semi- conservative replication
- Free DNA
- Strands of DNA acts as templates
- Need DNA polymerase
- Need chemical energy
Explain what happens in DNA replication
1) DNA helicase breaks hydrogen bonds so two strands separate
2) now there are 2 strands
3) polynucleotide acts as template to free nucleotide which bind to specific base pairs
4) nucleotides joined together by condensation reaction by enzyme DNA polymerase
5) two new DNA molecules
What is the evidence that supports semi-conservative replication
Centrifuge shows a band of DNA
1st generation - both n-14 and n-15
2d generation - some n14 +n15 and some only N14
Structure of ATP
🔴-🔴-🔴
\
Pentose sugar -◾️
Show the hydrolysis and condensation of ATP
ATP+H2O=ADP+Pi+E
Adenine triphosphate + water = adenine diphosphate+inorganic phosphate + energy
What enzyme is used in the ATP reaction hydrolysis
ATP hydrolase
What happens when ATP is hydrolysed
Provides an immediate release of energy
The energy can’t be stored
What happens in ATP reaction condensation
ATP synthase
5 roles of ATP
- Metabolic processes to build up molecules
- movement energy for muscle contractions
- active transport energy to change shape of proteins
- secretion needed to form lysosomes
- activation of molecules lowers activation energy