3.1.2 Enzymes and Digestion Flashcards
What are the three types of disaccharide?
- Maltose
- Sucrose
- Lactose
What is sucrose made of?
Glucose and Fructose
What is Lactose made of?
Glucose and Galactose
What is a condensation reaction?
A reaction which results in a product and a water molecule for each bond made
What is a glycosidic bond?
A bond between sugars caused by a condensation reaction ( with structure C-O-C )
What is Hydrolysis?
The opposite of a condensation reaction. Where a polysaccharide is broken down and the water molecule that was created in condensation joins back in
How to perform the Benedicts Test, or test or reducing sugars.
Add Benedicts reagent to a sample of sugar and heat. If it is a positive result, a brick red precipitate forms.
How do you perform a Benedicts test on non-reducing sugars?
- Add Benedicts reagent and heat. Get negative result.
- Add dilute HCL to separate sample to hydrolyse
- Neutralise by adding Sodium Hydrogen Carbonate
- Repeat Benedicts test and get positive result
How do you test for starch?
Add 2 drops of iodine/potassium iodide to 2 cubic centimetres of test solution. If blue/black, starch is present.
What is maltose made of?
Glucose and glucose
What enzyme breaks down starch?
Amylase
What is starch broken down into?
Maltose
What is maltose broken down by?
Maltase
Where is the only place lactose can be found?
Mammalian milk
Where is Sucrose commonly found?
In the phloem vessels of plants
What type of polysaccharide do alpha glucose monomers bond to create?
Starch
What type of polysaccharide do beta glucose monomers bond to create?
Cellulose
What are the three types of monosaccharide?
- Glucose
- Fructose
- Galactose
What 5 elements are amino acids made of?
Carbon, Nitrogen, Hydrogen, Oxygen and Sulfur (Only in Cytosine)
What is the structure of an amino acid?
A central carbon atom, with the following attached
- a hydrogen atom
- a basic amino group (usually NH2)
- a carboxy-acid group (usually COOH)
- and a variable R group
What is the central atom in an amino acid called?
Alpha carbon
How many different amino acids are there?
20
What are amino acids joined together by?
Peptide bonds
What is on the ends of a poly peptide chain?
A free amino (NH2) on the N-Terminus and a free carboxyl on the C-Terminus
What is the sequence of amino acids in a polypeptide chain dependant on?
The sequences of the bases in DNA
What is Buffer Solution?
A solution of amino acids resistant to change in pH. If excess of H+, they will affiliate with the nitrogen in the amino acids. If excess of OH-, the H from the C-OH group will disassociate and join the OH- to form H2O
What is primary amino acid structure?
The sequence, order and number of the amino acids in the polypeptide chain.
What is the secondary structure of an amino acid?
The most basic level of protein folding. Two most common types are Alpha-helix with parallel hydrogen bonds and Beta-pleated with antiparallel
What is tertiary structure?
Compact globular structure of a folded up polypeptide chain, held together by bonds between R groups of amino acids.
What are the possible types of bonds in tertiary structure?
- Weak hydrogen bonds
- Ionic Bonds
- Sulphur Bridges/disulphide bonds/Covalent S-S bonds.
(Hydrophobic Interaction) - Inward Protein Folding
(Hydrophilic Interaction) - Outward Protein Folding
What is Quaternary Structure?
The arrangement of different polypeptide chains with each other
What roles do globular proteins usually have?
Enzymes, Membrane proteins, receptors, storage proteins, etc.
What role do fibrous proteins usually have?
Structural roles like collagen, keratin and actin.
What is denaturing?
When temp or pH changes enough to cause the hydrogen bonds to break making the protein lose its 3D structure.
What is the test for proteins?
Buret test. Add equal volume of sodium hydroxide to aqueous protein sample. Add aqueous copper sulfate. If protein is present, solution will turn purple/lilac (and gloopy denatured protein collects at the bottom)