Cell 1010 Test 3

△G= +

-not spontaneous
-anabolic
-endergonic/endothermic
-supplying lots of activation energy
-products have more energy than reactants

△G= -

-spontaneous
-catabolic
-exergonic/exothermic
-little activation energy required
-reactants have more energy than products

Spontaneous

reactants will react

instantaneous

reactants will react once brought close together

what does ATP stand for?

adenosine triphosphate

How is energy stored in ATP?

electrostatic repulsion in the phosphate bonds

How much △G in the break down of ATP into ADP + iP

-7.3 kcal

How do you increase the rate of reaction outside the body?

Apply heat

How do you increase the rate of reaction inside the body?

1. enzymes: lower activation energy
2. ribozymes: RNA molecules acting as catalysts

How do enzymes work?

Lower activation energy needed to start a chemical reaction by causing a temporary change to the internal environment

Prosthetic Groups

small molecules permanently attached to inside of the enzyme

Cofactor

inorganic (ions) that bind to enzyme temporarily and help enzyme function

Coenzyme

Organic molecules (not proteins) that help enzyme function

Conditions important for enzymes

1. Optimal temperature
2. Optimal pH

Purpose of enzyme inhibitors?

regulate in body to conserve energy

Competitive inhibitors

Inhibitor competes for and binds to active site

Allosteric

inhibitor binds to allosteric site which changes the shape of the active site

When does irreversible inhibition occur?

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Cooperactivity

a typ elf allosteric regulation where all parts of enzymes receive info from inhibitor or activator

activator in cooperactivity

binds and opens all active sites

inhibitor in cooperactivity

makes all active sites inactive

Feedback inhibition

products act as the inhibitor

rate-limiting step

product binds to slowest enzyme which brings the reactions to a halt

aerobic respiration

respiration that requires O2 to receive the de-energized electron

anaerobic respiration

respiration where inorganic compounds receive the reenergized electrons (like CO2 and SO2)

fermentation

process by which organic compound receives the electron

Respiration

organic compounds (hydrocarbons) broken down for energy

Where does anaerobic respiration happen?

in muscles when working out and in the gut (bacteria)

Principle of redox

electrons are constantly being passed on

reduced

receives electrons (neg. potential energy)

oxidized

loses electrons (pos. potential energy)

Two ways ATP are synthesized

1. Direct
2. Indirect

Substrate-level phosphorylation

types of direct ATP synthesis where phosphate from high energy compound is combined with ADP to make ATP

Glycolysis

type of direct ATP synthesis where glucose is broken down

oxidative phosphorylation

type of indirect ATP synthesis where ATP is produced by chemiosmosis (diffusion of ions)

What does NAD+ stand for?

nicotinamide adenine dinucleotide

What is NAD+?

coenzyme that receives electron

What is NADH?

energy intermediate that carries electron

What is another name for Glycolysis?

Carbohydrate Catabolism

In Glycolysis, what does Glucose (6C) become?

With the breakdown of ATP into ADP + iP by Hexokinase, Glucose 6 Phosphate is formed

In Glycolysis, what does Glucose 6 Phosphate become?

The enzyme Phosphoglucoisomerase forms Fructose 6 Phosphate

In Glycolysis, what does Fructose 6 Phosphate become?

With the breakdown of ATP into ADP + iP by Phosphofructokinase, Fructose 1,6 Biphosphate is formed

In Glycolysis, what does Fructose 1,6 Biphosphate become?

The enzyme Aldolase forms both Glyceraldehyde 3 Phosphate (3C) and Dihydroxy Acetone Phosphate (3C)

In Glycolysis, what does Dihydroxy Acetone Phosphate (3C) become?

The enzyme Triose Phosphate Isomerase forms Glyceraldehyde 3 phosphate

In Glycolysis, what does TWO Glyceraldehyde 3 phosphate become?

With the breakdown of NAD^+ + 2e + 2H^+ into NADH + H^+ by Glyceraldehde 3 Phosphate Dehydrogenase and the addition of iP, 1,3 Bisphosphoglycerate is formed

In Glycolysis, what does TWO 1,3 Bisphosphoglycerate become?

With the building of ADP + iP into ATP by Phosphoglycerate Kinase, 3 Phosphoglycerate is formed

In Glycolysis, what does TWO 3 Phosphoglycerate become?

The enzyme Phosphoglyceromutase forms 2 Phosphoglycerate

In Glycolysis, what does TWO 2 Phosphoglycerate become?

The enzyme Enolase forms Phosphoenol Pyruvate and a water leaves

In Glycolysis, what does TWO Phosphoenol Pyruvate become?

With the building of ADP + iP into ATP by Pyruvate Kinase, Pyruvate is formed

What is put into Glycolysis?

Glucose
2 ADP
2 iP
2 NAD^+

What is the net products of glycolysis?

2 ATP
2 Pyruvates
2 NADH
2 H2O
2 H^+

Which steps of glycolysis are energy investment?

Steps 1-3

Which steps of glycolysis are the cleavage/priming phase?

Steps 4-5

Which steps of glycolysis are the energy liberation phase?

Steps 6-10

When is the first time oxidative decarboxylation happens?

In Pyruvate Oxidation

Oxidative Decarboxylation

Losing carbon in the form of CO2

In pyruvate oxidation, which enzyme removes CO2?

Pyruvate dehydrogenase

In pyruvate oxidation, which enzyme forms acetyl coA?

Dihydolipyl transacetylase

In pyruvate oxidation, which enzyme forms NADH?

Dihydrolipyl dehydrogenase

What starts in pyruvate oxidation?

2 Pyruvate (3C)

What is the product in pyruvate oxidation?

2 NADH
2 Acetyl coA
Co2

What are the other names for the Kreb Cycle?

-Citric Acid Cycle
-Tri Carboxylic Acid Cycle

In Krebs cycle, what does Oxaloacetate (4C) become?

With the breakdown of acetyl coA into coASH by Citrate Synthatase, Citrate (6C) is formed

In Krebs cycle, what does Citrate (6C) become?

With the removal of H2O then addition of H2O by Aconitase, Isocitrate is formed

In Krebs cycle, what does Isocitrate become?

With the removal of CO2 and the build up of NAD^+ + 2e + 2H^+ into NADH + H^+ by Isocitrate Dehydrogenase, Diketoglutarate is formed

In Krebs cycle, what does Diketoglutarate become?

With the addition of coASH, removal of CO2, and the build up of NAD^+ + 2e + 2H^+ into NADH + H^+ by Alpha Ketoglutarate Dehydrogenase, Succinyl coA is formed

In Krebs cycle, what does Succinyl coA become?

With the removal of coASH, conversion of GDP + iP into GTP which then converts ADP + iP into ATP all by Succinyl coA Synthetase, Succinate (4C) is formed

In Krebs cycle, what does Succinate (4C) become?

With the build up of FAD + 2e + 2H^+ into FADH2 by Succinate Dehydrogenase, Fumarate (4C) is formed

In Krebs cycle, what does Fumarate (4C) become?

With the addition of H2O by Fumarase, Malate is formed

In Krebs cycle, what does Malate become?

With the build up of NAD^+ + 2e + 2H^+ into NADH + H^+ by Malate Dehygrogense, Oxaloacetate (4C) is formed

What is the priming phase in Krebs cycle?

Oxaloacetate to Isocitrate

What is the oxidative phase in Krebs cycle?

Isocitrate to Succinate

What is the regeneration phase in Krebs cycle?

Succinate to Oxaloacetate

Total yield from Krebs cycle?

2 ATP
6 NADH
2 FADH2

Why is it Krebs "Cycle"?

The starting compound is regenerated

When does the complete glucose break down happen?

In Krebs cycle when all organic carbon becomes inorganic carbon (CO2)

How many ATP does Glycolysis produce?

2 ATP
5 ATP (from 2 NADH)
TOTAL 7 ATP

How many ATP does Pyruvate Oxidation produce?

3 ATP (from 2 NADH, 2 used to get inside)

How many ATP does Krebs cycle produce?

2 ATP
15 ATP (from 6 NADH)
3 ATP (from 2 NADH2)

How many ATP does 1 glucose produce?

30 ATP

What are the two functions of Oxidative Phosphorylation?

1. Oxidation of NADH and FADH2 to provide energy to make a proton gradient in inter membrane space
2. ATP synthase enzyme: H^+ flow by chemiosmosis through ATP synthase to provide energy for iP + ADP into ATP

Where does oxidative phosphorylation occur?

inner mitochondrial membrane

What is the first protein in the oxidative phosphorylation electron transport chain?

NADH dehydrogenase = proton PUMP

What is the second protein in the oxidative phosphorylation electron transport chain?

Succinate reductase = NOT proton PUMP

What is the third protein in the oxidative phosphorylation electron transport chain?

Cytochrome b-c1 = proton PUMP

What is the fourth protein in the oxidative phosphorylation electron transport chain?

Cytochrome oxidase = proton PUMP

What is the first carrier in oxidative phosphorylation electron transport chain?

Q= ubiquinone carrier
transport electron from I to 3 and 2 to 3.

What is the second carrier in oxidative phosphorylation electron transport chain?

Cytc= cytochrome C
transport electron from 3 to 4.

What happens to the two deenergized electrons at end of electron transport chain in oxidative phosphorylation?

ee + 2H^+ + 1/2O2 becomes H2O

In which direction does electronegativity increase in the electron transport chain for oxidative phosphorylation?

Toward the O2 at the end

How much ATP does one NADH produce in electron transport chain for oxidative phosphorylation?

1 NADH goes through 3 pumps and makes 2.5 ATP (1/2 ATP lost due to imperfect system)

How much ATP does one FADH2 produce in electron transport chain for oxidative phosphorylation?

1 FADH2 goes through 2 pumps and makes 1.5 ATP (1/2 ATP lost due to imperfect system)

Why is electron transport chain for oxidative phosphorylation not a perfect system?

1. Leaky mitochondrial matrix
2. Not all proton go through ATP synthase
3 Not all NADH formed go through electron transport chain

What are all the parts of the ATP synthase?

9-12: c = proton channel
1 a= connect c to b
2 b=connects membrane embedded parts to matrix embedded ones
ε= epsilon
ɣ= gamma, rotates clockwise direction (120 * 3) which forces all 3 β to change confirmation which releases ATP into mito. matrix
3 β = beta, conformational change
3 α = alpha
δ= delta, connects b to β

Succinate dehydrogenase being inhibited by oxaloacetate is an example of what?

Competitive inhibition in the Krebs Cycle

Phosphofructokinase being inhibited by ATP is an example of what?

Allosteric Inhibition in Glycolysis

Pyruvate Dcarboxylase being inhibited by NADH is an example of what?

Allosteric inhibition in Pyruvate Oxidation

Citrate synthase being inhibited by ATP is an example of what?

Allosteric inhibition in the Kreb Cycle

Describe the experiment done to prove a proton gradient was needed to make ATP

Proton gradient observed in light and dark environment in bacteria, only the light environment produced ATP

Describe the experiment done to prove a segment in the ATP synthase actually does a 360 rotation

Actin was attached to ɣ subunit and then ATP was sent through. Actin was observed to move 360 proving that the ɣ subunit also rotates 360.