carbohydrates exam paper Flashcards
what type of diffusion occurs through a protein channel
facilitated diffusion
what kind of molecules can use simple diffusion to move across membranes
small nonpolar molecules
what kind of transport is used to allow glucose with sodium irons to cross a membrane?
co-transport
describe the induced fit model of enzyme action
The Active site isn’t a complimentary shape to the substrate
when it binds the active site changes shape to allow it to fit
It does this by bending bonds which causes a reaction
what reducing sugar would you expect to be produced during chewing?
maltose because the salivary amylase breaks down starch
what are the enzymes required for the complete digestion of starch?
Maltase and amylase
when investigating the effect of chewing on digestion, why was it necessary for samples to be mixed with water hydrochloric acid and pepsin?
to mimic the effect of the stomach
give one reasons why it might be more efficient to attach lactate to beads as opposed to directly adding lactase to cows milk:
1) beads can be reused
explain why lactose free milk made after hydrolysis might taste sweeter than cows milk containing lactose
hydrolysis breaks down disaccharides and produces bad components in this case the monosaccharides were galactose and glucose and so more sugars are present 
Give two ways in which the structure of starch is similar to Celulose
1) they both contain glycosidic bonds
2) they are both polymers made of monomers 
why does maltase only break down Maltose?
The active site of maltase is complementary to the shape of maltose
what are enzyme inhibitors?
Inhibitors reduce the binding of enzymes to substrates
Describe the competitive inhibition of an enzyme
A competitive inhibitor is usually of a similar/complimentary shape to the active site and so it is able to bind to the active shape of that enzyme
describe a non-competitive inhibition of an enzyme
An inhibitor binds to another site on an enzyme other than the active site and prevents the formation of an active site and changes its shape
how would you test the sample of food for the presence of starch?
add a drop of iodine and if the sample turns blue black or purple colour starch is present
why is the rise in concentration of glucose in the blood slower if a carbohydrate is starch rather than sucrose?
starch requires two enzymes for it to be fully broken down. it first needs to be broken down into maltose by amylase and then maltose digested to glucose by maltase.
Whereas sucrose only needs one sucrase
where is the enzyme amylase produced?
pancreas
what is the product of a reaction catalysed by amylase?
maltose
where is the enzyme maltase produced?
In the Epithellium
what is the product of a reaction catalysed by maltase
glucose
how do use a biochemical test to show better reducing sugar is present
add a heated Benedix reagent to the sample and observe the colour
if the sample turns yellow red orange a reducing sugar is present
True or false?
starch glycogen deoxy both contain only the elements carbon hydrogen and oxygen
true
what is DNA Helicase made from?
amino acids
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