Metabolism II Exam 2

B5

pantothenic acid

B7

biotin

B6

Pyridoxine

B12

Cobalamin

B9

Folate

RDA for B5

5 mg/day

RDA for B7

30 microg/day

RDA for B6

1.5 mg/day

RDA for B12

2.4 microg/day

RDA for B9

400 microg/day

Cofactors of B5

CoA and ACP

Cofactors of B7

None. It binds to lysine in enzymes.

B6 Cofactors

PLP

B12 Cofactors

Methylcobalamin

B9 Cofactors

5-methyl-THF

Digestion of B5

Dephosphorylation by Phosphatases

Digestion of B7

Biotinidase breaks biocytin

Digestion by B6

Dephosphorylation by Phosphatases

Digestion of B12

R protein, IF

Digestion of B9

Conjugases (remove extra glutamate molecules)

Best source of B5

Shiitake Mushrooms

Best source of B7

Beef liver

Best source of B6

Pistachio nuts and Salmon

Best source of B12

Clams

Best source of B9

Shiitake Mushrooms and Spinach

B5 Transporters

SMVT (sodium dependent)

B7 Transporters

SMVT

B6 Transporter

Passive simple diffusion

B12 Transporter

IF receptor

B9 Transporter

PCFT, RFC, and FRs

What does the amino Acid Degradation of lysine and tryptophan end in?

Acetyl CoA for the TCA cycle or acetoacetate for ketogenesis

What does the amino Acid Degradation of Isoleucine and valine end in?

Acetyl CoA for the TCA Cycle or succinyl CoA

What does the Fatty acid (even chain) degradation end in?

Acetyl CoA

What can acetyl-CoA synthesize?

Cholesterol and fatty acid

What does the degradation of fatty acid (odd chain) end in?

Succinyl CoA

In degradation pathways, proteins and Fatty acids are converted to what?

Acetyl-CoA

Amino Acids (Lysine and Tryptophan) are converted to?

Acetyl-CoA (2C)

Amino Acids (Isoleucine and Valine) are converted to?

Propionyl-CoA (3C)

What type of amino acids are lysine and leucine?

Non-branch amino acids

What type of amino acids are valine, Isoleucine and leucine?

Branch Amino Acids

What is the first step in using amino acids for energy production?

Removing the amino group

What are two ways that an amino group is removed?

Deamination or Transamination

What is Deanimation?

The removal of an amino group (-NH2) from an amino acid

What is the end product of Deanimation?

Ammonium and Water

What is Transamination?

The transfer of an amino group (-NH2) from one amino acid to an alpha-ketoacid

What vitamin is required in the process of transamination and Deamination?

B6 in the form of Pyridoxal Phosphate (PLP)

In Deamination, the alpha-ketoacid product is used in what cycle?

Citric Acid Cycle

In Deamination, the Ammonium product is used in what cycle?

Urea Cycle

How many carbon molecules are produced by even chain FFAs?

2-Carbon Molecules

How many carbon molecules are produced by odd chain FFAs?

3 carbon molecules

What is the last step in even chain FFA Degradation?

Enters the TCA Cycle

What is the first step of the degradation pathway of Odd Chain FFAs?

FFA turns into Propionyl-CoA

What is the second step of the degradation pathway of Odd Chain FFAs?

Propionyl-CoA turns into Succinyl-CoA

What is the last step of the degradation pathway of Odd Chain FFAs?

Succinyl-CoA enters the TCA cycle

In the Synthetic pathways, Acetyl-CoA is used to build what?

Lipids

What is the first step in the synthetic pathway?

Acetyl-CoA is converted to citrate

What happens after Acetyl-CoA is converted to citrate?

Citrate is transported into the cytosol

In the cytosol, Citrate converts to what?

Acetyl-CoA

What enzyme is needed to turn Acetyl CoA to an even chain FFA and Propionyl-CoA to an odd chain FFA?

Fatty Acid Synthase (FAS)

In the synthetic pathways, both even and odd chain FFAs end up making what?

Triglycerides Glycerol + 3 FFA

Acetyl CoA exits the mitochondria and enters the cytosol by turning into?

Citrate

What enzyme turns Acetyl-CoA to Malonyl-CoA?

Acetyl-CoA Carboxylase (ACC)

What is the major regulatory point for FA synthesis?

ACC

What replaces CoA in malonyl CoA?

ACP

What does FAS use as a source of electrons?

NADPH

After NADPH is used by FAS, what does it produce?

NADP

What is B-oxidation?

The Break down of fatty acids in the mitochondria to produce Acetyl-CoA

Acetyl-CoA enters the TCA cycle to generate what?

NADH and FADH2

What enzyme cleaves citrate to convert it back to Acetyl-CoA?

ATP-citrate lyase (ACLY)

Degradation/Oxidation

generates reduced cofactors

Glycolysis produces…?

Acetyl-CoA

NADH and FADH2 are then used in ____?

The Electron Transport Chain

the ETC results in the production of?

ATP

What kind of cofactors does synthesis use?

Reduced CofactorsW

What kind of cofactors does synthesis produce?

Oxidized cofactors

What pathway does NADP enter to convert back to NADPH?

Pentose Pathway

Besides the Cytosol, where can Citrate be transported and convert back to Acetyl-CoA?

The Nucleus

In the nucleus, what is Acetyl CoA used for?

Acetylation of histone tails

What are histone tails?

Proteins that bind to DNA

Acetyl-CoA is derived from ___?

Patothenic acid (B5)

What enzyme uses Acetyl-CoA to increase acetylation of histones?

Histone Acetyl Transferases (HAT)

The increase in acetylation of histones by HAT results in an increase of what?

Gene expression

NAD is derived from what vitamin?

Niacin (B3)

What type of histone deacetylases (HDAC) is dependent on NAD (niacin)?

Sirt1

What enzyme reduces acetylation of histones?

Sirt1

The reduction of acetylation of histones results in?

The reduction of gene expression

Step 1 of increased expression by vitamin B5?

Pantothenic acid turns into CoA

Step 2 of increased expression by vitamin B5?

CoA turns into Acetyl-CoA

Step 3 of increased expression by vitamin B5?

Acetyl-CoA increases histone acetylation

How does histone acetylation affect gene expression?

increased expression

How does DNA methylation affect gene expression?

reduces gene expression

How does histone deacetylation affect gene expression?

reduces gene expression

How does histone biotinylation affect gene expression?

increases gene expression

What enzyme is used in the histone biotinylation process

Holocarboxylase synthase (HCS)

Step 1 of reduced expression by vitamin B9 and B12?

B9 donates a methyl group to B12

Step 2 of reduced expression by vitamin B9 and B12?

B12 turns into Methylcobalamin

Step 3 of reduced expression by vitamin B9 and B12?

Methylcobalamin donates methyl group to the amino acid homocysteine converting into methionine

Step 4 of reduced expression by vitamin B9 and B12?

methionine combines with ATP to create SAM

Step 5 of reduced expression by vitamin B9 and B12?

DNMTs (DNA Methyltransferases) remove methyl group from SAM and add it to the DNA

What happens when there is a genetic mutation of biotinidase?

The recycling of biotin and its absorption are prevented