Biology Quiz 2.4

Explain the relationship between an enzyme and a reactant molecule

Enzymes provide a site where reactants can be brought together to react. Reactants must collide with enough energy so that existing bonds will be broken and new bonds will be formed. The enzyme lowers the amount of energy needed to react.

The process of photosynthesis�where does it get its energy and where does it go?

Photosynthesis happens when the plants get there energy from the sunlight and use this energy to stay alive.

Know the role of an enzyme in a reaction

Enzymes provide a site where reactants can be brought together to react. The enzyme lowers the amount of energy needed to react.

Is photosynthesis endergonic or exergonic, explain why

Photosynthesis is an endergonic reaction because it is absorbing energy and an endergonic reaction is when something absorbs energy

What is your body's short term energy molecule`

CO2

What are coupled reaction�how do they work together

Chemical reaction with a common intermediate in which energy is transferred from one side of the reaction to the other. An example is the formation of atp, which is an endergonic process and is coupled to the dissipation of a proton gradient.

What is kinetic energy�give examples

Energy that a body possesses by virtue of being in motion.
When a ball is rolling down a hill

What is potential energy�give examples

The energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
A ball at rest on the top of a hill

What form does activation energy normally take?

It won't happen on its own, something needs to be done for it to supply enough energy to start a reaction.

What are exergonic reactions and be able to explain how they work

Exergonic reactions are those that release energy. These reaction occurs spontaneously and their rate is usually increased by enzymes.

What are endergonic reactions and be able to explain how they work

Endergonic reactions are those that store energy. They do not happen spontaneously and need supply of energy to occur.

How do cells regulate enzyme activity?

Temperature, pH, and regulatory molecules can affect the activity of enzymes.

What are catalysts�and how do they differ from enzymes

A catalyst is a substance that speeds up the rate of a chemical reaction. Catalysts work by lowering a reaction's activation energy. Enzymes are proteins that act like a catalyst in nature.

What factors effect the reactivity of enzymes?

Temperature, pH, and regulatory molecules can affect the activity of enzymes.