Enzymes and Energy Carriers Flashcards
metabolism
the sum of all chemical reactions in an organism
what is an enzyme
biological catalyst
biological-made by the body and used by the body
catalyst-speeds up chemical reactions without being used up itself
what are the 2 types of reactions
anabolic and catabolic
anabolic reaction
builds smaller molecules into larger molecules. requires energy
give 2 examples of anabolic reactions
photosynthesis, protein synthesis
catabolic reaction
breaks large molecules into smaller molecules. releases energy
2 examples of catabolic reactions
respiration, digestion
what is the anabolic enzyme
DNA polymerase
joins nucleotides forming DNA
what does the catabolic enzyme do
breaks down starch into maltose
chemical nature of an enzyme
protein
shape/structure of an enzyme
chains of amino acids folded into a 3D globular shape
what is the specificity of an enzyme
enzyme has a specific shape that only matches with a specific substance (substrate)
chemical composition
C, H, O, N
formula for enzymes
substrate + enzyme=product
active site
the part of the enzyme where the substrate combines to the enzyme.
lock and key model
the substrate fits precisely into the active site of the complementary enzyme (forming the enzyme substrate complex) the substrate changes to products and are released
induced fit model
- enzyme is specific to one particular substrate
- substrate moves into active sight of the complimentary enzyme
- the substrate causes the active site to change shape slightly to allow for a perfect fit, forming the enzyme substrate complex
- substrate changes to products and are released
- active site of enzyme returns to its original shape so that it can be reused.
+ diagram pg 76 book 1
how do conditions effect how enzymes work?
they have certain conditions where they work best, this is known as their optimum activity
what are the 2 factors that affect enzyme activity
temperature and pH
optimum temperature
temperature at which enzymes work their best
what is the optimum temp for animals and humans
37
what is the optimum temp for plants
20-30C
optimum pH
pH at which enzymes work at their best rate
what is the optimum pH for most enzymes
7-9
what is the exception for optimum pH
pepsin-found in stomach- pH 2
denaturation
when an enzyme has lost its shape and can no longer function
factors effecting denaturation
if pH and temp change sufficiently from the enzymes optimum the active site irreversibly changes shape
why can the enzyme no longer work if it is denatured?
if the active site has changed shape, the substrate cannot combine with the enzyme anymore and therefore can no longer function
what temp causes denaturation
anything above 60
what pH causes denaturation
anything out of the optimum of 7-9
bioprocessing
reactions involving enzymes to produce a product
bioreactor
a vessel in which products are made by microorganisms
immobilised enzymes
enzymes that are fixed to each other or inert material ie a gel - unreactive
what are the physical methods of immobilisation
absorption
enclosed by a membrane
Trapped in a gel
what are the chemical methods of immobilisation
bonded to a support
bonded to each other
what are the advantages of immobilistation
immobilised enzymes are:
easily removed from product
can be reused reducing cost
more stable
the efficiency of the enzyme is no effected
uses of immobilisation
lactase breaks down lactose into glucose and galactose. these monosaccharides are used as sweeteners
penicillin acylase breaks down penicillin to form new anti biotics
what are the 3 energy carriers
ADP, NADP+, NAD+
what does ADP stand for
adenosine diphosphate
(di = 2 phosphates)
what type of energy does ADP have
low energy
what does ATP stand for
adenosine triphosphate
(tri= 3 phosphates)
what type of energy does ATP have
high energy
what do molecules energy carriers do
they trap and transfer energy during cellular processes
what does NAD stand for
nicotinamide adenine dinucleotide
what does NADP stand for
nicotinamide adenine dinucleotide phosphate
what process is NAD+ involved in?
respiration
what process is NADP+ involved in?
photosynthesis
what energy does NAD+ have
low
what energy does NADP+ have
low
how is NADH formed?
when NAD+ combines with 2 electrons and 1 proton it becomes NADH
how is NADPH formed
when NADP+ combines with 2 electrons and 1 proton is forms NADPH
