enzymes - the basics Flashcards
why are active sites so specific?
what does this mean for when the enzyme wishes to attach to a substrate?
what does the attachment end up forming?
- due to specific folding in the tertiary structure of the protein
- the enzyme can only attach to a substrate complementary in shape due to its specific active site
- enzyme substrate complex
what is the lock and key model like really quickly?
what does this model suggest?
how does the activation energy get lowered by this model?
what 3 things happen after the complex is formed?
- substrate fits into enzyme due to being complementary in shape and an enzyme substrate complex is formed
- active site is a fixed shape
- substrate slightly distorts in shape once combined in the E.S.C
- products are released, active site empty and ready to be reused
what is the induced fit model?
what does the enzyme moulding allow to occcur?
how is activation energy lowered?
what 2 things happen after the complex is formed?
- the enzymes active site is induced: slightly changes shape to mould around substrate WHEN IT BINDS
- the ESC to be formed
- moulding places strain on bonds
- the products are released and the enzymes active site returns to its og shape
what is the shape of globular proteins?
what are hydrophilic amino acids? (what is attracted to water)
what is one feature of globular proteins related to this hydro stuff?
why?
where in the globular protein would you find hydrophobic amino acids then and why?
- spherical
- r groups attracted to water
- soluble in water
- have hydrophilic amino acids on its surface to be able to interact with water molecules
- in the centre to stay clear of water molecules
what is the role of fibrous proteins?
what do fibrous proteins form?
what is one feature of these proteins? and what from this can you gather it has a large proportion of?
- structurous one
- long rope like molecules
- insoluble in water
- hydrophobic amino acids
pro of lock and key:
2 cons:
- gives insight into enzyme specificity
- suggests enzyme is rigid when the active site is actually flexible
- doesn’t explain how inhibitors and activators bind to other sites and change activity
what are 2 pros of induced fit?
- explains how inhibitors and activators affect enzyme acitivity
- explain how activation energy is lowered
condensation reactions ________ bonds
name the stuff:
a-
g-
c-
t-
u-
what is the name of the bond between nucleotides?
what does rRna do?
- makes
- adenine
- guanine
- cytosine
- thymine
- uracil
- phosphodiester
- folds with proteins to make ribosomes
what is a ribosome?
what is a gene?
where are introns found?
- site of protein synthesis made up of protein and rRNA
- a sequence of dna bases which code for the sequence of amino acids in a polypeptide
- within a GENE
3 key features of both DNA and mRNA
DNA:
- has introns
- double stranded
- very long
mRNA:
- no introns
- single stranded
- very short
what do we call a curved graph suddenly going straight?
what does limiting mean according to me?
“as substrate conc increases the rate of reaction increases why?” (mention what is limiting)
“as substrate conc increases further rate of reaction plateaus why?”
- plateau
- relevant
- substrate conc is limiting. more enzyme substrate collisions. more enzyme substrate complexes formed
- all enzyme active sites are filled and so subs conc is no longer limiting and so another factor is ex. enzyme conc
effect of temperature:
“as the temp increases the rate of reaction increases why?”
“as temp increases further the rate of reaction decreases why?”
- more kinetic energy. more enzyme subs collisions. more ESC formed
- hydrogen and ionic bonds broken. tertiary structure changes. no longer complementary to substrate. enzyme is denatured. no ESC formed
too high of a ph meaning?
too low of a ph meaning?
what happens if the ph is above or below the optimum? (as in what happens to the enzyme like the previous flashcard)
- too many OH- ions
- too many H+ ions
- these charges from the ions we’ve mentioned interfere with the charges of the amino acids in the active site. this breaks hydrogen and ionic bonds causing the tertiary structure to change meaning the active site changes shape. enyme is denatured and less ESC formed
what does a competitive inhibitor look like?
what does it do (3)
_____ substrate conc and _____ rate of reaction
- similar shape to substrate
- binds at the active site. blocks the substrate from binding at the active site. less ESC formed
- increases substrate conc and increases rate of reaction
what does the non competitive inhibitor do? (4)
____ substrate conc and has ____ rate of reaction
- binds at a site away from the active site
- causes active site to change shape
- substrate no longer complementary and so can’t bind
- NO ESC formed
- increase substrate conc and has no effect on rate of reaction
