Biology 181 Chapter 8 Study Questions

Front 1

What is energy?

Back 1

The capacity to cause change, especially to do work (to move matter against an opposing force).

Front 2

What are the different types of energy (potential and kinetic)?

How do those relate to biological systems?

Back 2

Potential Energy – The energy that matter possesses as a result of its location or spatial arrangement (structure).

Kinetic Energy – The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter.

Front 3

What are the types of work that cells perform?

Back 3

Coupled Reaction – Energy released by exergonic (release energy) reaction drives endergonic (require energy) reaction. Breakdown of ATP releases energy used by muscle. ATP-->ADP+(P).

Front 4

What is Thermodynamics?

Back 4

The study of energy transformations that occur in a collection of matter. See first law of thermodynamics; second law of thermodynamics.

Front 5

What are the 1st and 2nd laws of Thermodynamics?

Back 5

1st Law of Thermodynamics The principle of conservation of energy: Energy can be transferred and transformed, but cannot be created or destroyed.

2nd Law of Thermodynamics The principle stating that every energy transfer or transformation increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat.

Front 6

What is meant by an open and closed system?

Is the earth an open or closed system?

Back 6

Closed system (liquid in a thermos) = isolated from surroundings

Closed Hydroelectric system – Water flowing downhill turns a turbine that drives a generator providing electricity to a light bulb, but only until the system reaches equilibrium. ΔG<0 (Before Equilibrium) and ΔG=0 (After Equilibrium)

Open Energy System – Open system (plants) = energy is transferred between the system and surroundings
Transform sunlight --> chemical energy (food)

Energy input constantly – Open Hydroelectric System – Flowing water keeps driving the generator because intake and out flow of water keep the system from reaching equilibrium. ΔG<0 (Flow is constant)

Open

Front 7

What are enzymes?

Back 7

Enzymes – A macromolecule serving as a catalyst, a chemical agent that changes the rate of reaction without being consumed by the reaction.

Front 8

What do enzymes do to chemical reactions?

Back 8

They speed them up by lowering the energy required to complete a task.

Front 9

How are enzymes sometimes named?

Back 9

They are named after their substrate ending in -ase.

Front 10

What is a substrate?

Back 10

Substrates are substances that fit together much like the correct puzzle piece into the active site of the enzyme.

Front 11

What is an enzyme-substrate complex?

Back 11

An enzyme-substrate complex uses the reactants (substrates) and the enzyme. The enzyme is like a catalyst that reduces the required activation energy and speeds up the chemical reaction.

Front 12

What is ATP again?

Back 12

Adenosine Triphosphate or ATP – An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive energonic reactions in cells.

Front 13

Describe how ATP is like a rechargeable battery?

Back 13

It is an energy carrier which stores, transports, and regulates energy.

Front 14

What are endergonic and exergonic reactions?

Back 14

Endergonic - Required Energy (+ΔG) - CO2+H2O+Solar Energy-->Sugar+O2

Exergonic - Release Energy (-ΔG) - Coal+O2-->CO2+Energy

Front 15

How does endergonic and exergonic relate to spontaneous and non-spontaneous reactions?

Back 15

Spontanious - Occures w/o help + Release Energy - Sliding Downhill + Diffusion

Non-Spontanious - Occurs only if energy is added - Walking Uphill

Front 16

What are some things that regulate or affect enzyme activity?

Back 16

Heat and pH

Front 17

What is allosteric regulation?

Back 17

It is a non-competative inhibitor that changes the shape of the enzyme by using the allosteric site.

Front 18

What is a competitive inhibitor?

Back 18

It is something that fits in the puzzle slot of the enzyme that blocks the substrate from the ability to bind to the enzyme.

Front 19

What is a non-competitive inhibitor?

Back 19

This changes the enzymes shape thus blocking the substrate from being able to connect properly with the enzyme.