Enzymes and metabolism

C1.1

Enzymes as catalysts

catalysts are defined as substances which increase rate of reaction but don’t cause a change in the reaction

enzymes act as biocatalysts, made by living cells to speed up reaction

enzymes convert substrates into products

without enzymes life processes would be very slow

Role of enzymes in metabolism

network of interdependent and interactions of chemical reactions that occur in living organisms.

molecules involved in metabolism are called metbolites

reactions inside cells, extrcellular reaction —> digestion of food in intestines

one molecule is transformed into another, generally chain reactions, some cycles generally metabolic reactions are catalysed by an enzyme

enzyme specificity

enzyme catalyse one specific reaction or group of reaction, this allows organism to make lot of differrent enzymes

cells with complez metabolism make thousands of enzymes

allows organisms to control metabolism, it allows organism to perform functions much faster than they would ideally.

Anabolism

build smaller molecules into large ones, require energy.

Photosynthesis

macromolecules are produced from monomers uses energy from ATP, this occurs through condensation as water is one of gthe products,

protien synthesis by ribosomes

dna synthesis

synthesis of complex carbohydrates include starch, cellulose and glycogen

Catabolism

Break down of large molecules into smaller releasing energy. Energy is captured by coupling catabolic reaction to synthesis of ATp, which is used in cell

• digestion of food

• cell resporation —> glucose or lipids are oxidised to co2 and water

Metabolism= catabolsim +anabolism

exergonic

releasing free energy in process of the reaction

endergonic

reaction which needds energy to process

globular protiens

active site for catalysis

globular protiens have three dimensional structures and properties which allows them to work as catalysts/enzymes

the location at which substrate binds in an enzyme is called an active site

the shape and properties of active sit eand substratre should match for them to bind,

substrate+active site= products which are releaed and active site is free for another reaction to be catalysed.

certain amino acids are needed for chemical reactions to convert subtrate into product

if enzyme is altered catalysis won’t occur

induced fit binding

subtrate moves randomly till it is close to the active site, and as it gets clsoer the enzymes surface attracts substrace molecules towarsds active site.

induces fit binding theory suggests that an enzyme, when binding with its substrate, optimizes the interface through physical interactions to form the final complex structure.

lock and key is an interaction in bindign which causes change in the lengths and angles of both the substrate and active sit e

in case of second substrate, it goes to another region of the active site and binds there this is also causes changes in the structure thus allowing binding.

These changes make it easier for substrates to bond and break to create products.

molecular motion and collisions

molecular motion occurs because an enzyme can only at its active site with the substrate if they are close to each other

substrates and active site come together is called active site collision

molecular motion in liquids

• molecules are closely packs but thye can move anyways and direction is random, thus they are bound to collide and interact with each other

• successful