Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
Different forms of energy depends on what?
|
The stability and complexity of the system in consideration.
|
|
What is the second law of thermodynamics?
|
Every time there is energy transfer or transformation, there is an increase in the overall entropy of the universe
|
|
Describe free energy and entropy in an unstable system vs. stable system
|
An unstable system has a low degree of entropy and a greater amount of free energy than a stable system.
|
|
What is Gibb's free energy equation? What do the variables stand for?
|
deltaG = deltaH - TdeltaS
G = Gibb's free energy H = Total energy T = Time S = Entropy |
|
What's the relationship between positive/negative G value and energy in a reaction?
|
A negative G value means the system gives up energy and is exergonic. A positive G value requires energy and is endergonic.
|
|
What is the important chemical equation regarding glucose in metabolism?
|
glucose + oxygen >> carbon dioxide and water
c6h12o6 + 6o2 >> 6co2 + 6h2o |
|
What are the components of ATP?
|
A phosphate group, a ribose group, and an adenine group.
|
|
Which bond is most important in ATP? What's an example?
|
The third phosphate bond. An example is the synthesis of glutamine from glutamic acid and ammonia.
|
|
What's the energy investment required to initiate a reaction?
|
The activation energy
|
|
What occurs immediately after a reaction begins?
|
It enters the transition-state, which has higher energy than any other part of the reaction.
|
|
What are enzymes?
|
Enzymes are proteins that act as biological catalysts.
|
|
What do catalysts do? What do they not do?
|
Catalysts lower the required energy of activation. They do not cause reactions that could not ordinarily occur.
|
|
What enzyme catalyzes RNA? What does it not do?
|
RNA polymerase catalyzes formation of RNA but not DNA
|
|
What hydrolyzes RNA polymers?
|
The enzyme RNA nuclease
|
|
What important enzyme is involved with phosphorylation, and what does it do?
|
Hexokinase is an important kinase enzyme that accelerates the phosphorylation of a hexose monosaccharide like glucose.
|
|
How do enzymes alter the activation state of a reaction?
|
1. Orienting substrates
2. Add charges to substrates 3. Use covalent catalysis - temp. bond to substrate 4. Alter shape of substrates |
|
What conditions affect enzyme activity?
|
1. Temperature and pH
2. Substrate concentration 3. Cofactors 4. Regulators and inhibitors |
|
What is allosteric regulation?
|
An action at a site other than the active site.
|
|
Discuss activators vs. inhibitors
|
Activators stabilize enzymes to make reactions occur, inhibitors stabilize an inactive form. This is different from cooperativity!
|
|
What is cooperativity?
|
Cooperativity is an allosteric activation where a substrate stabilizes the active form of an enzyme. This is different from an activator!
|
|
What are the two metabolic pathways, and what do they do?
|
Anabolic pathways synthesize the building blocks of macromolecules.
Catabolic pathways break down macromolecules and fuel molecules. |
|
What was the first example of feedback inhibition in class?
|
When isoleucine binds to an allosteric site on threonine deaminase
|
|
How much energy is required to synthesize glucose from co2 and h2o?
|
686kcal of energy per mol of glucose (180g)
|
|
What are the main processes in glucose metabolism? Where is ATP generated?
|
1. Glycolysis
2. Citric acid (or Krebs) cycle 3. Electron transfer chain & oxidative phosphorylation ATP is generated by oxidative phosphorylation in the inner mitochondrial membrane |
|
What bond has the most potential energy and why?
|
Covalent C-H bonds have the greatest potential energy because bonds are equidistant between C and H.
|
|
Discuss reduction and oxidation
|
A molecule that gains one or more electrons or hydrogen atoms is reduced. Oxidation is the other way around.
|
|
Discuss reducing and oxidizing agents
|
Reducing agents donate an electron or hydrogen atom.
Oxidizing agents accept an electron or hydrogen atom. |
|
Which agents do what in the metabolism of glucose?
|
Glucose is the reducing agent (and is oxidized) while oxygen is the oxidizing agent is reduced).
|
|
What's the deltaG of redox reactions?
|
Redox reactions have a negative deltaG, so energy is removed to be used elsewhere.
|
|
What are electron carriers? What's important about them?
|
During the catabolism of glucose, electrons are transferred along a series of electron donors and acceptors called electron carriers. This produces energy in small packets.
|
|
What are two key electron carriers involved in the breakdown of glucose?
|
NAD and FAD
|
|
What are the six steps in the release of energy from glucose?
|
1. Transport glucose into cell
2. Glycolysis: glucose > 2 pyruvates 3. Pyruvate oxidation > acetyl coA 4. Citric acid / Krebs cycle 5. Electron transport chain 6. ATP synthase |
|
Where does glycolysis occur?
|
In the cytoplasm.
|
|
Where does the Krebs cycle occur?
|
In the mitochondria.
|
|
Where does the electron transfer chain occur?
|
In the inner membrane of the mitochondria.
|