BIOC 3022

Glycolysis (0.8 < 0.95 -\> need to make ATP so glucose-6-phosphate is metabolized to pyruvate/acetyl CoA for use in TCA cycle)

What happens to glucose-6-phosphate when the energy charge is 0.80?

Glycogen synthesis (0.97 \> 0.95 -\> have enough ATP so glucose must be stored as glycogen)

What happens to glucose-6-P when the energy charge is 0.97?

Glycogenolysis (0.8 < 0.95 -\> Need ATP so glycogen is broken down into glucose to make pyruvate/acetyl CoA for TCA)

What happens to glycogen when the energy charge is 0.80?

UDP glucose is added to extend the glycogen chain (0.97 \> 0.95 -\> store energy in form of glycogen)

What happens to glycogen when the energy charge is 0.97?

Broken down by pyruvate dehydrogenase complex into acetyl coA (0.8 < 0.95 -\> need ATP so acetyl coA will enter TCA cycle)

What happens to pyruvate when the energy charge is 0.80?

Gluconeogenesis (0.97 \> 0.95 -\> have enough ATP so store pyruvate as glucose/glycogen)

What happens to pyruvate when the energy charge is 0.97?

1. Phosphoenolpyruvate via pyruvate kinase

2. Alanine via alanine: alpha-ketoglutarate amino transferase

What compounds (2) can pyruvate be derived from and through what enzyme?

1. Acetyl CoA via pyruvate dehydrogenase complex

2. Oxaloacetate via pyruvate carboxylase

3. Lactate via lactate dehydrogenase

4. Acetaldehyde via pyruvate decarboxylase

What compounds (4) can be derived from pyruvate and through what enzymes?

(Acyl-CoA) dehydrogenase

The enzyme most similar to succinate dehydrogenase from the beta oxidation of fatty acids is...

(Enoyl-CoA) Hydratase

The enzyme most like fumarase from the beta oxidation of fatty acids is...

(Hydroxy-CoA) dehydrogenase

The enzyme most like malate dehydrogenase from the beta oxidation of fatty acids is...

Acyl Carrier Protein

ACP stands for...

A 3 carbon compound on ACP formed by carboxylation of

acetyl-ACP (or acetyl-CoA). It is the donor in fatty acid biosynthesis

What is malonyl CoA?

Exactly the reverse

How does the chemistry of fatty acid synthesis compare to that of beta oxidation?

HMG-CoA reductase

What enzyme is the key control point in cholesterol biosynthesis?

1. Phosphorylation

2. Protein degradation

3. mRNA degradation

List three ways that HMG-CoA reductase is regulated

COX 1

Aspirin inhibits this enzyme

COX 2

Vioxx inhibits this enzyme

Thromboxane

What hormone is produced by COX 1?

Prostacyclin

What hormone is produced by COX 2?

Promotes

Thromboxane (promotes/reduces) blood clotting

Reduces

Prostacylcin (promotes/reduces) blood clotting

Nitrogen

What atom do cells have to deal with when they break down amino acids that they did not have to deal with when breaking down carbohydrates?

Glutamate dehydrogenase

What enzyme removes the alpha amino group from glutamate?

Transferred onto an alpha-ketoglutarate to make glutamate by a specific aminotransferase enzyme

How are the alpha amino groups of amino acids other than glutamate removed?

Arginase

What enzyme removes two nitrogens from arginine as urea in the urea cycle?

Decarboxylation of glucose-6-phosphate in the pentose phosphate pathway

How are five carbon sugars generated?

Synthesize nucleotides for DNA/RNA synthesis

Why might growing cells need a lot of 5-carbon sugars?

Generate carbon backbones of different lengths

What problem do transketolases solve?

Complex I

What component of the ETC is most similar to Photosystem II?

Coenzyme Q

What component of the ETC is most similar to plastoquinone?

Complex III

What component of the ETC is most similar to cytochrome B6F?

Cytochrome C

What component of the ETC is most similar to plastocyanin?

Complex IV

What component of the ETC is most similar to Photosystem I?

None

What component of the ETC is most similar to ferrodoxin?

None

What component of the ETC is most similar to ferrodoxin/NADP+ reductase?

NADH and FADH2

What is the initial electron donor for the mitochondria?

H2O

What is the initial electron donor for the chloroplast?

O2

What is the terminal electron acceptor in the mitochondria?

NADP+

What is the terminal electron acceptor in the chloroplast?

ATP

What is the only product of cyclic photophosphorylation?

CO2, ATP, NADPH

What are the inputs of the Calvin Cycle?

Glucose-6-phosphate (fructose-6-phosphate)

What is the product of the Calvin cycle?

Rubisco

What is the key enzyme of the Calvin Cycle?

Fixes carbon by adding CO2 to ribulose

What does Rubisco do?

Glucose, ketone bodies

What energy source(s) does the brain use?

Fatty acids

What energy source can the brain not utilize?

Acetyl CoA

What compound are ketone bodies made from?

Creatine kinase

What enzyme phosphorylates ADP using the high energy bond found in phosphocreatine?

Alcohol dehydrogenase and aldehyde dehydrogenase produce NADH

How does alcohol metabolism lead to excess NADH?

Hypoglycemia, diabetes, low blood pH, elevated VLDL, fatty liver disease, kidney damage, addiction

What problems can excess NADH cause in the body?

Anaerobic metabolism of glucose in cancer cells. Anaerobic metabolism produces less ATP than aerobic

What is the Warburg effect? Why is it surprising?

Gag

HIV gene that encodes the core, matrix, and nucleocapsid proteins

Pol

HIV gene that enodes reverse transcriptase, integrase, and protease

Env

HIV gene that encodes gp120 and gp41

Tat

HIV gene that encodes the transactivator of transcription

Rev

HIV gene that encodes the regulator of viral expression

CD4 and CCR5

What host molecules are required for fusion of HIV to the cell?

gp120 and gp41

What viral molecules are required for fusion of HIV to the cell?

gp120 changes conformation upon attachment which allows gp41 to unfold hydrophobic tails that insert into the host cell membrane. Once inserted, gp41 refolds, bringing the virus in contact with the host cell membrane

What conformational change takes place in gp120 and gp41 when HIV fuses with the host cell membrane?

Being error prone allows for genetic diversity which allows virus to evade immune response and repopulate patient

Why is the low fidelity of HIV reverse transcriptase an advantage for the virus?

Rev allows unspliced mRNA from the nucleus to be exported which serve as the genome for the next virus. Without it, there would be no genetic material in the new virus

Why is the rev protein essential for HIV replication?

Rapid replication, strong selection for resistance, gradual loss of immune competence, latent T cells allow virus to hide for decades

Four reasons why the HIV virus always wins

Virus mutates rapidly so antibodies aren't effective against new variety; immunogenic parts of surface proteins are not accesible to immune system

Why are HIV vaccines so hard to develop?

Glucagon

You just woke up after fasting for 18 hours: what hormone is controlling your

metabolism?

Glycogen, Gluconeogenesis

What is the source of blood glucose after fasting?

Gluconeogenesis

What pathway produces glucose from pyruvate?

Pyruvate carboxylase

What enzyme converts pyruvate to oxaloacetate using CO2 and ATP?

Insulin

You ate a big breakfast 2 hours ago: what hormone is controlling your metabolism?

Glycolysis, Krebs, e-

transport, oxidative phosphorylation

If your energy charge is 0.91, what pathways are active?

Glycogen synthesis

If your energy charge is 0.97, what pathways are active?

UDP-glucose pyrophosphorylase

What enzyme produces UDP-glucose from glucose-1-phosphate?

Adrenaline

You overslept and are late for a quiz: what hormone is active in your body?

1. Glycogen breakdown

2. Beta oxidation

1. Glycogen synthesis

Name two pathways that are activated and one that is inactivated by adrenaline

1. Glycogen phosphorylase kinase (GPK)

2. Triacylglycerol lipase

1. Glycogen synthase

Name two enzymes that are activated and one that's inactivated by adrenaline

O2, NAD+

You missed the bus and sprinted 2 km to class: name 2 things you ran out of.

1. Glycolysis

2. Kreb's cycle

3. Electron transport chain

4. Oxidative phosphorylation

You chug 2 litres of Coke (with high fructose corn syrup). Your energy charge is 0.80. Name 4 pathways you use

Fatty acids produce acetyl CoA when degraded which consumes oxaloacetate and prevents ATP production because the TCA cycle is inhibited

You eat two sticks of butter after sprinting 2 miles. Your energy charge is 0.80.