Proteins and Enzymes Flashcards
What are the 4 basic categories of amino acids?
Acidic
Basic
Polar
Non-polar
What is the primary protein structure a source of?
Versatiliy in protein structure and function
What is an enzyme co-factor?
A non-protein component needed for activity
In which three main ways do enzymes catalyse reactions?
Increase rates of spontaneous reactions
Lower activation energy of biochemical reactions
Accelerate movement towards reaction equilibria
A large Km signifies what?
A low affinity of the substrate for the enzyme
What type of protein is an enzyme?
Globular protein
Where are co-enzymes usually produced from?
A vitamin
Spontaneous reactions must have what type of delta G value?
A negative one
Enzymes reduce what in a reaction?
The activation energy required
What are the 3 ways that enzymes can reduce activation energy?
Entropy reduction
Desolvation
Induced fit
What does a large Vmax indicate?
Very fast enzyme
What type of Vmax does glucokinase have?
A high Vmax
How can you separate gluco and hexo kinase?
Electrophoresis
How can a competitive inhibitor be stopped?
By diluting the solution with the substrate
Allosteric effectors are examples of what types of inhibitors?
Non-competitive inhibitors
What 3 things make up the amino acid structure?
Amino group
Carboxylic acid group
Side chain
What does an asymmetric central carbon allow the formation of?
Mirror images (enantiomers)
What is the primary structure of a protein classed as?
The sequence of amino acids in a polypeptide chain
What is the secondary structure of a protein described as?
Spatial arrangement of amino acid residues that are near each other in the linear sequence
Where are the H bonds situated in a beta pleated sheet?
Between the amid groups of linear polypeptide chains
Does porin have a beta pleated sheet?
Yes
What is the tertiary structure of a protein described as?
The spatial arrangement of amino acid residues that are far apart in a linear sequence
Where do ionic interactions take place in a protein?
Between 2 close, oppositely charged R groups
Disulphide bridges are between what 2 things in a protein?
Cysteine residues
Where are disulphide bridges common?
Extra-cellular proteins
What protein structure does chymotrypsin have?
Tertiary
What is the quartenary structure of a protein?
Spatial arrangement of individual polypeptide chains in a multi-subunit protein
What remains the same after a protein has been denatured?
The primary structure of a protein
Why does the primary structure of a protein remain the same after protein denaturation?
Denaturation reactions are not strong enough to break the peptide bonds
What is protein structure dependent on?
DNA sequence coding for amino acids
What are glycoproteins composed of?
Protein and carbohydrate
What is an example of a glycoprotein?
Immunoglobulin
Glycosylation is a process that occurs where?
Endoplasmic reticulum
Golgi apparatus
What is the function of a lipoprotein?
Transport water-insoluble fats and cholesterol in the blood
What is a metalloprotein?
Protein molecule with a bound metal ion
Which part of a haemoglobin chain binds the oxygen molecule?
The Haem group at the centre
What type of protein is collagen?
Fibrous protein
What type of protein is a LDL receptor?
Glycoprotein
