Ch. 3

Explain what happens in Glycolysis?

*Each glucose molecule turns into 2 molecules of Pyruvate. *2 ATP molecules are consumed, but 4 ATP are produced. *grand total=2 pyruvate, 2 NADH, 2 ATP and 2 H+.

Explain what happens in Kreb Cycle?

*Glucose oxidation can't occur until pyruvate can enter mitochondrial matrix, so pyruvate is converted to acetyl coA. *Reaction for ONE OF the Pyruvates is: 2-Co2, 3-NADH, 1-ATP, 3 -H+,1 FADH

What occurs during Oxidative Phosphorylation?

*Hydrogen atoms or electrons are transported through compounds known as Electron Transport Chain (which releases Energy). *Through chemiosmotic coupling, the energy to make ATP is harnessed. (10 NADH *3)+(1 FADH X 2)=34 ATP

Explain Allosteric regulation

A molecule known as a modulator binds and induces a change to the enzyme's conformation that alters the shape of active site and causes a change in enzyme's activity by altering catalytic rate and its affinity.

When a substrate binds to an enzyme it does so through weak interactions. What kind of bonding is involved in this binding? What bonding is never used with these interaction.

Can be bound through: *Hydrogen bonds *Ionic bonds *Vanderwal forces But NOT Covalent Bonds!!

During a fast the rates of which reactions will increase?

Glycogenolysis, Gluconeogenesis

A reaction that uses water molecules to break up chemical bonds in the reactant molecule is called ___________.

Hydrolysis

The _________ of ATP liberates its stored energy for cellular use.

Hydrolysis

MOst Cells in the body can obtain their requisite energy from the ____________ of ____________.

Oxidation; glucose.

The term _____________________ is used to describe reactions that remove electrons from an atom or molecule. These electrons must be accepted by another atom or molecule in a process known as _______________.

Oxidation; reduction.

Glucose oxidation cannot proceed beyond glycolysis unless __________.

Oxygen is present!

What is the most common chemical group used in covalent modulation?

Phosphate group. (Protein kinase and phosphatase)

What is a genetic disorder which causes breaking down, jaundice, lethargy. How do you treat this?

Pyruvate Kinase Deficiency. *To treat this you would have to remove the spleen. *This is similar to Hereditary Spherocytosis, but with spherocytosis you have a structure problem in PYruvate Kinase Deficiency you have a metabolic disorder.

A reaction that removes electron from a reactant molecule is called __________.

oxidation.

Reactions such as glucose oxidation ____________ energy that is used to synthesize ATP.

release

What are the two mechanism for altering the activity of existing enzymes?

1. Allosteric Regulation 2. Covalent Regulation

Name at least 3 factors which affect the rates of chemical reactions.

1. Concentrations of the reactant and product. 2. Temperature 3. Height of the Activation Energy Barrier 4. Enzymes

What are the factors which affects the Rates of Enzyme-Catalyzed reactions?

1. Enzyme's Catalytic Rate. 2. Enzyme's Substrate concentration. 3. Enzyme Concentration 4. Affinity of enzyme for substrate 5. Temp and pH.

What are the 3 distinct stages of oxidation of glucose and where do these all occur?

1. Glycolysis (Cytosol) 2. Krebs Cycle (Mitochondrial Matrix) 3. Oxidative Phosphorylation (inner mitochondrial membrane)

The strength of the interaction between a protein and a ligand is called ____________.

Affinity. *This depends on the degree of complementary shape and the number and strength of the chemical interactions. (The higher the affinity, the more likely that a given protein will have a ligand bound to it.)

Describe the Law of Mass Action

An increase in concentration of reactants relative to products tend to push reaction forward and an increase of concentration of products relative to reactants tend to push a reaction in Reverse.

______________ reactions occur in the forward direction when they are part of a metabolic pathway that has a net negative delta E.

Anabolic

When cells need energy to perform work or to run energy-requiring reactions, they obtain it through what means?

By hydrolyzing previously synthesized ATP. atp+h20=adp + Pi+energy

Enzymes are proteins, but many enzymes possess additional non-protein components called ________.

Cofactors. *These are necessary for the enzymes to function properly.

Phosphorylation can also be a _______________ reaction and dephosphorylation can also be considered a ____________ reaction.

Condensation; Hydrolysis.

Affinity is how well things get together. A high affinity means it binds _________. What about low affinity.

Easily=high affinity Low affinity=Doesn't bind at all.

An energy-requiring reaction is called an ______________ reaction

Endergonic reaction. *Synthesis of proteins is an example (energy is required to form each peptide bond in a protein) Change of E=(+)

The reaction ADP + Pi → ATP is an example of a __________ reaction

Energonic/condensation/oxidative phosphoylation or substrate-level phosphorylation. (All 4 things are examples of the reaction.)

Metabolic reactions are normally catalyzed by ___________ that frequently require an additional non protein ___________.

Enzymes, Cofactors.

In ___________ reactions, The activation energy for the forward reaction is less than for the reverse reaction.

Exergonic

An energy-releasing reaction is called an ____________ reaction.

Exergonic. *If the free energy of reactant (left side of equation) is greater than the product (right side of equation) then the value of the free energy change for the reaction is a negative number and is an EXERGONIC reaction. Burning of paper is an example.

Normaly Catabolic reactions are _________ and proceed spontaneously. Anabolic reactions are normally ____________ and require energy to proceed.

Exergonic; Endergonic.

Each turn of the kreb cycle produces ________.

FADH, In the Krebs cycle, NAD and FAD are reduced to NADH and FADH2, respectively, in reactions that remove carbon atoms from the pyruvate molecules that enter the cycle. But only 1 ATP molecule is synthesized.

T or F:Chemical Equilibrium is reached when the concentration of the reactant equals the concentration of the product.

FALSE!!! Chemical Equilibrium is when there is NO net reaction direction. The reactant is converted to the product AT THE SAME RATE the product is converted to the reactant.

Give two examples of cofactors.

NAD and FAD.

In order for a reaction to proceed spontaneously in the forward direction, the energy change must be ________.

Negative

Molecules that enter a chemical reaction are called ___________.

REactants

What are these reaction: 2 H + 2e(-)=H2 A-B + 2H= HA-BH

Reduction Reactions

To catalyze a reaction, an enzyme molecule must first bind to a reactant molecule. What do we call this reactant molecule in enzyme-catalyzed reactants?

Substrate. *If this substrate is able to bind to enzyme, these will form an enzyme-substrate complex and if these are bound long enough, then this substrate will be converted to product. After this, the enzyme molecule emerges from reaction in the same form and is NOT consumed.

What does the oxidation of glucose do?

This releases energy and cells utilize some of this released energy to synthesize ATP.

Why do neurons need energy?

To depolarize

T or F: A reaction with a positive ΔE goes in reverse spontaneously.

True

T or F: Gluconeogenesis requires running the reactions of glycolysis in reverse.

True

What is covalent regulation?

Where changes in an enzyme's activity occurs as a result of covalent bonding of a specific chemical group to a site on the enzyme molecule.

We use about 40% of the energy released from one mole of glucose. The 60% that remains becomes __________.

heat