Test 2 Flashcards
What are the two basic forms of energy?
Potential energy and kinetic energy
What is potential energy?
stored energy
What is kinetic energy?
energy in the process of doing work
What determines how much potential energy is stored in a system?
- the function of order
- the more order the system, the more potential energy
Which side has more order / more potential energy?
AB –> A + B
- the reactants have more order so more potential energy
- reactants are less stable
Exothermic / Exergonic reaction
- reduction in potential energy
Activation energy
energy required to start a reaction
2 ways to overcome activation energy
- Heat (energy)
- Catalyst/Enzymes
What is an active site?
region of an enzyme where a substrate binds and undergoes a chemical reaction
What is a cofactor?
an inorganic substance that binds to an enzyme and activates an active site
(only required for certain enzymes)
What is a coenzyme?
an organic molecule that binds to an enzyme and activates an active site
(required for all enzymatic activity)
Endothermic/Endergonic Reaction
- increase in potential energy
- driven by/ requires exergonic reactions
- requires energy and enzyme
What supplies the neccesary energy to drive all of the endergonic processes of the cell?
Cellular respiration
Cellular Respiration (aerobic)
a series of exergonic reactions that break down organic molecules to release their energy and harnessing that energy to create adenosine triphosphate (ATP)
What is ATP (adenosine triphosphate)?
an energy carrier
What are the 4 processes of cellular respiration?
- Glycolysis
- Pyruvate oxidation
- Kreb’s cycle
- Oxidative Phosphorylation
Glycolysis
- breaking down a sugar
Occurs: in cytoplasm
Reactants: glucose, 2 ADP, 2 Pi (inorganic phosphate), 2 NAD+
Products: 2 ATP, 2 NADH, 2 Pyruvate
Overall Picture: coupling of endergonic and exergonic rxns to create ATP
What is the transfer of electrons called?
Oxidation and Reduction
Pyruvate Oxidation
Occurs: mitochondrial matrix
Reactants: 2 pyruvate, 2NAD+, 2 CoenzymeA
Products: 2 CO2, 2NADH, 2 AcetylCoA
Overall Picture: coupling of endergonic and exergonic rxns to create ATP
Citric Acid Cycle / Kreb’s Cycle
Occurs: in matrix
Reactants: 2 AcetylCoA, 2 FAD+, 6 NAD+, 2 ADP, 2 Pi
Product: 2 FADH2, 6 NADH, 2 ATP, 4 CO2
Overall picture: coupling of endergonic and exergonic rxns to create ATP
What is FADH2?
A high energy electron carrier
How many CO2 molecules are produced from cellular respiration?
6 CO2 molecules
How many H2O molecules are produced from cellular respiration?
6 H2O molecules
Step 1 of oxidative phosphorylation
- Generate a proton motive force
- high energy electrons from NADH and FADH2 are passed down an electron transport channel to a low energy state (EXERGONIC; HIGH TO LOW ENERGY) DOWN CONCENTRATION GRADIENT
- energy that is released is used to pump H+ across a membrane to produce a [H+] gradient = proton motive force (ENDERGONIC; ACTIVE TRANSPORT) UP CONCENTRATION GRADIENT
Step 2 of oxidative phosphorylation
- Chemiosmosis
- use the proton motive force to phosphorylate ADP to make ATP
What is oxidized and reduced in oxidative phosphorylation?
Oxidized: NADH and FADH2
Reduced: O2
Oxidative Phosphorylation
FOR ONE GLUCOSE MOLECULE
Occurs: on inner membrane of mitochondria
Reactants: 10 NADH, 2 FADH2, O2, ADP, 2 ATP
Products: 38 ATP, NAD+, FAD+, 6H2O
What is the theoretical max number of ATP molecules created in cellular respiration?
36 ATP per glucose molecule
How many ATP molecules does NADH produce?
3 ATP
How many ATP molecules does FADH2 produce?
2 ATP
Anaerobic Respiration
Bacteria use non-oxygen (SO4) final electron receptor in oxidative phosphorylation