chapter 4- enzymes Flashcards
what are enzymes made up of
amino acids=proteins (globular proteins)
are enzymes made up of high molecular weight
yes
what do globular proteins have
a spherical shape, alpha helix molecules, 1y, 2y and 3y structure- hydrogen, ionic and disulphide bonds
what do intracellular enzymes do
the synthesis of polymers into monomers in cells?????
what does anabolic mean
building up molecules it is required for growth
what does catabolic mean
breaking down molecules into sub units
eg of work down by a catabolic enzyme
digestion- amalase breaks carbohydrates into starch then glucose
eg of work down by anabolic enzymes
nail growth
what are enzymes
biological catalysts that speed up the ror without getting used up in the reaction and changing the produced substances.
An enzyme is a protein that acts as a catalyst, increasing the rate of a biochemical reaction.
It does this by lowering the activation energy.
what is enzymes specificity
the ability of an enzyme to select a specific substrate from a range of chemically similar compounds
what is a cofactor
a non protein chemical compound or metallic ion that is required for the enzymes activity as a catalyst. they can be considered as helper molecules that assist in biochemical reactions
what is a holoenzyme
refers to the active enzyme with its nonprotein component.
what is an apoenzyme
is an inactive enzyme without its nonprotein part
what is an enzyme
a protein that acts as a catalyst increasing the rate of a biochemical reaction by lowering the activation energy
Why is the tertiary structure of enzymes important?
the active site has a specific tertiary structuee which is complementary to a specific substrate enabling an enzyme-substrate complex
what is an active site
the group of amino acids that make up the region where a substrate fits to catalyse a reaction
An active site is the region on an enzyme where a substrate fits to catalyse a reaction
The shape of the active site is determined by the enzyme’s tertiary structure
what does the lock and key hyphothesis state
that the binding of the substrate with the enzyme occurs because the active site has a shape which is complementary to the shape of the substrate meaning the substrate fits the active site like a key fits a lock
The lock and key hypothesis says that the active site and substrate have fixed shapes that are complementary
what does the induced fit hyphothesis state
that the interaction between the substrate and the tertiary structure of the enzyme causes the shape of the active site to change slightly allowing the substrate to “fit”
The induced-fit hypothesis says that when the substrate starts to bind to the active site, the shape of the active site changes. This puts stress on the bonds in the substrate and makes them easier to break. This lowers the activation energy.
what is a substrate in the context of enzymes
a substance that is acted on or used by another substance or process
define activation energy
the energy required to bring about a reaction
Activation energy is the minimum amount of energy required to bring about a reaction.
what is a competitive inhibitor
an inhibitor that binds to the active site of an enzyme
what is a non-competitive inhibitor
an inhibitor that binds to an enzyme but not at the active site at an allosteric site
what are coenzymes
organic molecules such as vitamins loosely bound to enzymes allowing them to by catalytic
what are cofactors
inorganic ions which combine with apoenzyme to activate it forming holoenzyme
example of a cofactor
chloride ion for amylase
what is a prosthetic group
inorganic ion or organic molecules that are tightly bound to the enzymes
xample of a prosthetic group for an enzyme
zinc ion for carbonic anhydrase
is amylase intra or extracellular
extra
is catalase intra or extracellular
intra
are vitamins a source of coenzymes
yes
is Cl- a cofactor for carbonic anhydrase
no it is for amylase
do Both inorganic ions and coenzymes bind temporarily to enzymes.
yes
immobilised enzymes can be produced by which method
enclosing enzymes within a partially permeable membrane
