Essay on Unit 2 Test notes

Submitted By MeghannnRoberts
Words: 815
Pages: 4

Unit 2 Biology Test
Chapter 3
Laws Of thermodynamics
First law of Thermodynamics- Energy is neither created nor destroyed during the conversion from one form to another
Second Law- Every process increases the entropy of the universe he laws apply to all systems that involve energy and energy transformations. Respiration and photosynthesis fall in this category. So in photosynthesis, the plant does not make energy but just transforms light energy into food energy (convervation law 1 ). During the process, not all of the energy is converted, since most of it is lost as heat (transformation law 2). To keep the system going, it needs a regular stream of energy (entropy, law 3). I hope you get the drift. Respiration also involves energy conversions .
Exergonic- A reaction where free energy is RELEASED
Endergonic- A reaction where free energy is REQUIRED

Reactant energy -------- Product energy

Bond Energy- The minimum amount of energy needed to break a particular type of bond.
Kinetic energy- The energy of a moving object
Potential Energy- The energy stored in a substance , through composition and position
Activation Energy- The minimum amount of energy to needed to start a chemical reaction
Covalent bonds contain the most energy, hydrogen bonds contain much less (therefore easier to break)
Entropy- Increases when complex molecules break down
- Decreases when complex molecules are synthesized
- Is a measure of the degree of disorder in a system
Hydroylsis reaction - Hydrolysis is a reaction involving the breaking of a bond in a molecule using water.
Phosphorylation- the process of attaching a phosphate group to another organic molecule, causes the molecule to gain free energy and become more reactive. ( 3 types) Substrate Level Substrate Level (quick and dirty) Oxidative (slow and steady)
Definition Direct formation of ATP via one enzyme catalyzed reaction, in which a phosphate containing molecule transfers a phosphate group to ADP ATP is produced INDIRECTLY through a series of enzymes catalyzed redox reactions, in which electrons are passed from organic molecules, to electron carrier coenzyme molecules such as NAD+ and FADH, and ultimately passed to O2
When its used Glycoysis and Krebs Cycle Electron Transport Chain
ATP yield 4 ATP / glucose 32-34 ATP/Glucose

Photophosphorolation- the conversion of ADP to ATP in photosynthesis. Two types cyclic and no cyclic.
Enzymes- enzymes reduce active energy for endergonic and exergonic reactions.
Enzymes lower the required energy: brings the substrate closer to the active site, allowing the chemical bonds to weaken and change with less energy. The enzyme is lowering the entropy of the substrate.
Increasing reaction time: Enzymes act as biological catalysts, increasing the rate of the reaction without changing into a different molecule or raising the temperature. The enzyme does not add energy ( energy cannot be created or destroyed) but it speeds up a reaction.
1) Enzymes bring both substrates into contact by binding them to a specific site, this allows them to collide which allows the bonds to be broken faster
2) Enzymes bring a substrate into a changed environment and alter the substrate.
3) Enzymes can distort or bend the shape of a substrate, which weakens the chemical…