Biochemistry Flashcards
6 recall points of enzymes
Definitions, Names and activation energy, Graphs, Rate, Clinical, Measurements
What is a cofactor (Enzymes)
the non-protein component needed for the reaction e.g. magnesium
What is a coenzyme (Enzymes)
the heat-stable substance that can aid enzyme reactions e.g. FAD from riboflavin
What is a isoenzyme (Enzymes)
an enzymes that catalyse the same reaction but vary in structure and other biochemical properties
Ways in which enzymes lower the activation energy
Entropy reduction
Desolvation
induced fit
What is Vmax and Km?
Vmax = The reaction rate when all enzymes are saturated Km = The substrate concentration when the reaction is at ½ the maximum velocity (Vmax)
Limiting factors for the rate of enzymes
Enzyme concentration
Substrate concentration
Temperature (limitation to conditions, there will be an optimum)
pH (limitation to conditions, there will be an optimum)
Inhibitors. There are two types of inhibitor competitive (Vmax unchanged, Km increases because it takes more substrate to overcome the inhibition) and non-competitive (Vmax decreased, Km remains the same)
Measuring enzymes allows us to ….
Detect suspected disease Confirm suspected disease Assess the response to therapy Assess organ function Detect inherited metabolic disease detection of vitamin deficiencies
Conditions that will alter the enzyme concentration in the plasma
Hypoxia Cellular damage Physical damage Immune disorders Microbiological agents Genetic defects Nutritional disorders
Challenges with working with enzymes
The measurements are not specific
They require particular conditions
Assays must be optimised
Recall points for carbohydrates
Functions Shape Monosaccharides Disaccharides Polysaccharides Glycogen and disease Glycoproteins Proteoglycans Metabolism
What are the functions of carbohydrates
- Metabolism. Sugar and starch is a major source of energy collected through catabolism.
- Potential energy store. i.e. in starch and glycogen
- Structural and protective i.e. cells walls (in plants) and extracellular matrices of animal cells.
- Communication, where they are found on the surface of the cell. i.e. blood types
Why are carbohydrates stored in polymers?
- Space saving
- Creates non-reducing ends allowing for ready synthesis and degradation
- exist as a hydrate gel which is not soluble and therefore isn’t able to leave the cell
Examples of monomers
Glucose
Galactose
Fructose
Bonds formed between monomers in carbohydrates
Glycosidic between the hydroxyl group and anomeric group of two monosaccharides
Bonds formed between proteins
Peptide bonds
What bond forms between nucleotides
Phosphodiester
What is an anomeric carbon?
Carbon with 4 different groups bonded to it
What does an anomeric carbon do ?
Stabilise the structure
Examples of disaccharides
Maltose
Lactose
Sucrose
What is maltose?
Mainly comes from the break down of starch however is found in beer and baby foods.
Reducing sugar as anomeric carbon is available for oxidation.
What is lactose?
Main sugar in milk.
Formed by one galactose and one glucose monomer.
Reducing sugar as anomeric carbon is available for oxidation.
What is sucrose?
Sugar in ‘table sugar’ and used as a sweetener in food.
Not a reducing sugar as anomeric carbon is not available for oxidation.
What are the two broad types of polysaccharide?
Homopolysaccharide and heteropolysaccharide