Topic 1A - Biological Molecules Flashcards
What is a monomer
Small subunit which can be combined with other small sub units to create a larger molecule.
What is a condensation reaction?
A reaction which joins two molecules together with the formation of a chemical bond. It releases a water molecule.
What are the two types of glucose?
Alpha glucose and beta glucose
What bond forms between two monosaccharides?
Glycosidic bond
Give two examples of monomers?
Monosaccharides
,Amino acids
,Nucleotides
What type of reaction involves the breakage of the chemical bond between two monomers using water?
Hydrolysis reaction
What is the name of the bond that forms between two monosaccharides?
Glycosidic bond
What monosaccharides make up the disaccharides:
maltose?
sucrose?
lactose?
a) glucose + glucose
b) glucose + fructose
c)glucose + galactose
What monomers makes up polysaccharides?
Monosaccharides
Describe the Benedict’s test
Add Benedict’s reagent to a sample and heat in a water bath that’s been brought to a boil.
If the test positive colour change will go from BLUE to either GREEN, AMBER, OR BRICK RED.
How do you test for non-reducing sugars
Add a new sample of the test solution to the sample, add dilute HCl, heat in a water bath that has been brought to a boil
Neutralise it by adding sodium hydrogencarbonate
Carry out the Benedict’s test
What are 3 characteristics of amylose
- long
- unbranched
- chain of alpha glucose
- compact (good storage molecule)
What are 3 characteristics of amylopectin
- long
- branched
- chain of alpha glucose
- lots of side branches, these break down for quick release of glucose
What are 3 characteristics of glycogen
- polysaccharide of alpha glucose
- has lots of side branches (allows glucose to be released quickly)
- compact molecule (good for storage)
What are 3 characteristics of cellulose
- polysaccharide of beta glucose
- form straight cellulose chains
- cellulose chains are linked together by hydrogen bonds to form strong fibres called micro fibrils
- prove structural support to the cells walls
Describe the iodine test for starch
Add iodine dissolved in potassium iodide solution to the sample
If colour changes from orangey brown - blue black, then iodine is present
What are the 4 components of triglycerides
1 glycerol (hydrophilic)
3 fatty acids (hydrophobic)
What’s the difference between a saturated and an unsaturated fatty acid
An unsaturated fatty acid has a carbon carbon double bond , which causes the chains to kink.
What’s the structure of a phospholipid
1 phosphate
1 glycerol
2 fatty acids
Describe what triglycerides are
- Mainly used as energy storage molecules
- Good for this as they have long hydrocarbon tails which contain lots of chemical energy
- A load of energy is released when they are broken down
- they are insoluble in water so they dont affect the water potential of the cell and cause the cell to swell
What bond forms between a fatty acid and a glycerol
An ester bond
What is the phospholipid bilayer
Phospholipids make up the phospholipid bilayer of the cell membrane
Their heads are hydrophillic and their tails are hydrophobic, leading to the head facing outwards toward the water and the tails facing inwards away from water
The centre of the bilayer is hydrophobic, so water soluble substances cant easily pass through - the membrane acts as a barrier to those substances
What is the emulsion test for lipids
Shake the test substance with ethanol for about a minute, then pour the solution into water
Any lipid will show up as a milky emulsion
The more lipid there is, the more noticeable the milky colour will be
What’s the monomer for proteins
Amino acids
What are the 4 components which form an amino acid
Variable group (R group)
Amine group
Carboxyl group
Hydrogen
What is the primary structure of a protein
Basic sequence of amino acid that join together to form a polypeptide chain
What is the secondary structure
Hydrogen bonds form
Makes the chain automatically coil into a alpha helix or fold into beta pleated sheets
what is the tertiary structure
More bonds form between the different parts of the chain
Hydrogen, ionic bonds and disulphide bridges form
Creates the 3D structure
What is the quaternary structure
When peptide chains join pother peptide chains and form polypeptides. Held together by several bonds
How does an enzyme speed up reactions
Lowers the activation energy by two ways:
being attached to the enzyme holds them close together, reducing any repulsion between the molecules so they can bond more easily
if the enzyme is catalysing a breakdown reaction, fitting into the active site puts a strain on bonds in the substrate, so the substrate molecule breaks up more easily
Describe the lock and key method
This is where the substrate fits into the enzyme the same way a key fits into a lock
The enzyme active site is complimentary to the substrate
Describe the induced fit model
This model states that the substrate not only has to be the right shape to the active site, it has to make the active site change shape aswell
As the substrate binds the active site changes shape slightly to form the enzyme substrate complex
What are the 4 factors that affect the rate of enzyme activity
Temperature, pH, substrate concentration, enzyme concentration
How does a competitive inhibitor work
It will have a similar shape to the substrate
They compete with the substrate for the active site
No reaction will occur
How does a non-competitive inhibitor work
Non-competitive inhibitor fits onto the enzyme on the allosteric region away from the active site
Causes the active site to change shape so the substrate can no longer fit into the active site
