proteins Flashcards
How does the rate of an enzyme inhibitor decrease the rate of an enzyme-controlled reaction? (3)
-inhibitor has a similar shape to the substrate
-binds to active site
-prevents E.S complexes forming
if stale bread has changed starch which acts as a competitive inhibitor of amylase in the ileum, how does this reduce weight gain? (3)
-less hydrolysis of starch
-to maltose
-less absorption of glucose
describe the structure of a protein (5)
-1’=amino acid sequence
-2’=long chains of pp fold into alpha helix or beta pleated sheet held by H bonds
-3’=aa seq determines where H/I/D bonds are
-further folds into 3D shape
-4’=prosthetic group
why is there a higher concentration of fatty acids and a lower concentration of triglycerides an hour after eating comp to 45 mins? (3)
-fatty acids increase due to lipase
-triglycerides decrease due to hydrolysis
-of ester bonds
To see the concentration of triglycerides and fatty acids in a sample, why did the scientist immediately heat it to a high temp after? (2)
-denature enzyme
-prevent hydrolysis
describe the roles of micelles in the absorption of fats into cells lining the ileum (4)
-micelles include bile salts and fatty acids
-makes fatty acids more soluble in water
-carries fatty acids to ileum lining
-fatty acids absorbed by diffusion
how does E.S complexes increase the rate of reaction? (2)
-lowers activation energy
-by weakening bonds
when lyxose binds to an enzyme, why does it increases the rate of reaction? (3)
-binding to enzyme changes shape
-changes active site
-more E.S complexes form
describe the induced fit model and how an enzyme acts as a catalyst (3)
-substrate binds to active site
- active site changes shape SO it becomes complimentary to substrate
-lowers activation energy
explain this (2)
-as phosphate increases, more e.S complexes form
-at 40 all active sites are occupied
explain how the active site of an enzyme causes a high rate of reaction (3)
-lowers activation energy
-induced fit CAUSES active site to change shape
-E.S complexes form and CAUSES weakened bonds
how are dipeptides similar? (3)
-amine group
-carboxyl group
- two R groups
how are dipeptides different? (1)
- ## different R groups
what does the position of the spots show about the three amino acids? (3)
-they moved to the negative electrode cuz they’re positively charged
-moved different distances cuz have diff charges
- shows two spots as two aa have same charge
describe how a non-competitive inhibitor reduces the rate of an enzyme-controlled reaction? (3)
-attaches to other binding site not active site
-changes shape of active site
-no longer complimentary SO substrate cant fit
how does a peptide bond form b/t two amino acids to form a dipeptide? (2)
-condensation reaction
-b/t amine and carboxyl group
how is the 2’ of a pp produced by bonds b/t amino acids? (2)
-H bonds
-form b/t amine and carboxyl
-form alpha helix or beta pleated sheet
why does two proteins have the same number and type of proteins but diff 3’? (2)
-different aa seq
-forms H/I/D bonds in diff places
why does maltase only hydrolyse maltose?
-active site complimentary to substrate
-only maltose binds to it
-forms E.S complexes
why is attaching lactase to beads more efficient than adding it directly to cow’s milk? (3)
-beads can be reused
-don’t need to remove lactase from milk
-allows continuous process
why does lactose-free milk hydrolysed by lactase tastes sweeter than regular milk?
-galactose and glucose
-more sugars so sweeter
why is it important to maintain a constant blood pH? (3)
-enzymes affected by changes in pH
-changes shape
-less O2 binds w/ haemoglobin
Contrast competitive with non competitive inhibitor (4)
- C binds w/ a.s|NC binds w/ allosteric
- C doesn’t change a.s shape|NC changes shape of a.s
- C enzymes still available|NC enzymes unavailable
- C higher chance of collisions w/ high sub conc|NC not possible
