Atoms, Ions & Bonds
What negatively charged particle is found in an atom?
Electron
Is water a polar or non-polar molecule?
Polar
What are the starting substances in a chemical reaction called?
Reactants
What is a biological catalyst called?
An enzyme.
What enzyme did we investigate in the lab?
Catalase
What determines which element an atom belongs to?
The number of protons in the atom.
Which part of a water molecule has a slight negative charge?
The oxygen atom.
What are the substances formed during a chemical reaction called?
Products
What do enzymes do to the activation energy of a chemical reaction?
They lower the activation energy.
What substance does catalase break down?
Hydrogen peroxide, H₂O₂.
What happens to electrons when a covalent bond forms?
The atoms share one or more pairs of electrons.
Which part of a water molecule has a slight positive charge?
The hydrogen atoms
What happens to atoms during a chemical reaction?
The atoms are rearranged as bonds are broken and new bonds are formed.
What is the name for the reactant that an enzyme acts on?
Substrate
What two products form when catalase helps break down hydrogen peroxide?
Water and oxygen
How does an atom become an ion?
It gains or loses electrons.
What type of attraction occurs between the slightly positive hydrogen of one polar molecule and a slightly negative atom of another?
A hydrogen bond.
Are atoms created or destroyed during a chemical reaction? How do you know?
No. The atoms are conserved and rearranged into new substances.
In the lock-and-key model, where does the substrate bind to the enzyme?
The active site
Name two factors the lab identifies that can affect catalase activity.
Temperature and pH.
Compare ionic and covalent bonds in terms of what happens to electrons.
Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.
Name two properties of water that result from hydrogen bonding.
Any two of the following: high specific heat, cohesion, adhesion, or surface tension.
What is activation energy?
The energy required to start a chemical reaction.
Why can extreme temperature or pH cause an enzyme to stop functioning properly?
The change can denature the enzyme, altering its shape so the substrate can no longer properly bind to the active site.
In the catalase investigation, what should remain the same except for the factor being tested?
The controlled variables, or constants. The investigation changes one chosen variable while keeping the other variables constant.