enzymes and water review 11/9/26

chemical reaction

a process that changes or transforms one set of compounds or chemicals into another

reactants

the elements or compounds that enter into a chemical reaction

products

the elements or compounds that are produced in a chemical reaction

catalyst

a substance that speeds up the rate of a chemical reaction by lowering the activation energy

activation energy

the energy needed to get a reaction started

what is an enzyme

biological catalysts

what do enzymes do

enzymes speed up reactions that take place in living cells by lowering the activation energy

how do enzymes function

the substrate binds to the active site forming an enzyme-substrate complex where the reaction takes place forming products. the active site on the enzyme stresses the formation or breaking bonds in the substrate

how an enzyme works

enzymes provide a site (active site) where reactants (substrates) can be brought together, reducing the activation energy needed for the reaction.

what can affect the way an enzyme works

pH and temperature leading denaturing

denature

changes shape which then changes the function

competitive inhibitors

slow down or stop the activity of the enzyme by binding to the active site

noncompetitive inhibitors

slow down or stop the activity of the enzyme by binding to another part of the enzyme

polar molecules

electrons are not shared equally between H and O in the covalent bonds.

why is a water molecule polar

electrons are attracted more strongly to the 8 protons in the oxygen atom than the 1 proton in the two hydrogen atoms. weak hydrogen bonds are formed.

cohesion

the attraction between molecules of the same substance. it causes water molecules to be drawn together.

adhesion

the attraction between molecules of different substances

capillary action (adhesion)

water travelling up against a force of gravity in a narrow tube

heat capacity

the amount of energy needed to raise a substance’s temperature by making its molecules move faster

water heat capacity

water’s heat capacity is relatively high, meaning the water heats more slowly and retains heat longer than other substances. humans sweat to release heat, maintaining homeostasis. oceans and lakes absorb large amounts of heat with only small changes in temperature

water in living things

water accounts for approximately 60% of mass of the human body. growth, development, movement, maintaining homeostasis takes place in chemical reactions in a water environment. This is why water is essential to all living things.

pH

pH scale indicates the concentration of H+ ions in a solution

acids

any compounds that release H+ ions into solution. pH <7 is acidic-more H+ ions that OH- ions

bases

any compounds that produce hydroxide ions in solutions. pH >7 is basic-more OH- ions than H+ ions

solution

a type of mixture in which all the components are evenly distributed

suspension

a mixture of water and non-dissolved materials

solute

substance that is dissolved

solvent

substance in which the solute dissolves in