2. Molecular Biology Flashcards
Explain the production of lactose-free milk.
Filtered through immobilised lactase
hydrolyse lactose to glucose and galactose
For lactose intolerant people
Distinguish between the structure of the chromosomes of prokaryotes and eukaryotes. (2)
Prokaryotes have circular DNA but eukaryotes have linear chromosomes
Histones associated with DNA in eukaryotes but naked DNA in prokaryotes
Some prokaryotes have plasmids but eukaryotes don’t
Eukaryotes have multiple chromosomes whereas prokaryotes typically have one
Eukaryotes have telomeres but prokaryotes don’t
Eukaryotes DNA can supercoil due to histones but not prokaryote DNA
Explain the secondary structure of alpha amylase.
alpha helices, beta pleated sheets
The picture mainly consists of alpha helices
Some beta pleated sheets in the picture
spiral coils held together by hydrogen bonds
hydrogen bonds between oxygen C-O and hydrogen atoms N-H of amino acids
Explain how enzymes catalyse chemical reactions
Enzymes form enzyme-substrate complexes binding of substrate to active site of enzyme enzyme changes shape slightly decreases activation energy Enzymes bind to specific substrates
State the function of amylase and the site of production.
breakdown starch to maltose. Salivary glands and pancreas
What is maltase break down? Where does digestion of starch mostly take place?
Maltose into glucose. Small intestines.
What does lactase break down?
lactose into glucose and galactose.
What does sucrase break down?
sucrose into glucose and fructose.
Explain, with reference to the thermal properties of water, how humans respond to overheating.
Water has high latent heat of vaporization
More energy required to evaporate water (breaking hydrogen bonds)
Evaporation has cooling effect, water is a good evaporative coolant
sweating as an example of using water as a coolant
