100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
MCT Block 3 EXAM WITH CORRECT ANSWERS 2024 $18.49
Add to cart
Quickly navigate to
Preview
  2.  
  3. MCT Block 3 Part 1
  4.  
  5. MCT Block 3 Part 1

Exam (elaborations)

MCT Block 3 EXAM WITH CORRECT ANSWERS 2024
 0 purchase
  • Course
  • MCT Block 3 Part 1
  • Institution
  • MCT Block 3 Part 1

major substrate sources that enter TCA cycle correct answers carbohydrates (glucose) fatty acids ketone bodies alanine ethanol what enzyme converts pyruvate to acetyl-coA correct answers pyruvate dehydrogenase complex (PDC or PDH) features of pdc correct answers -large multienzyme comp...

[Show more]

Preview 4 out of 42  pages

Document information

  • August 21, 2024
  • 42
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers

Subjects

Written for

  • MCT Block 3 Part 1
  • MCT Block 3 Part 1

Seller

avatar-seller
HopeJewels

Reviews received

Content preview

MCT Block 3 Part 1

major substrate sources that enter TCA cycle correct answers carbohydrates (glucose)
fatty acids
ketone bodies
alanine
ethanol

what enzyme converts pyruvate to acetyl-coA correct answers pyruvate
dehydrogenase complex (PDC or PDH)

features of pdc correct answers -large multienzyme complex
-three types of protein subunits
-utilizes five cofactors
-regulated

what chemistry is used to convert a-ketoglutarate to succinyl-coA correct answers
same as PDH

E3 subunit is same protein that serves as E3 subunit of akg dh complex

3 enzymes of pdc correct answers -pyruvate decarboxylase (E1)
-dihydrolipoyl transacetylase(E2)
-dihydrolipoyl dehydrogenase (E3)

pdc 5 cofactors correct answers -thiamine pyrophosphate
-lipoic acid
-coenzyme A
-FAD
-NAD+

(Tender Loving Care For Nancy)

E1 reaction correct answers releases CO2 and attaches remaining carbons to
Thiamine-PPi

E2 reaction correct answers first moves carbon chain from TPP to lipoic acid, then
carbons are transferred to coenzyme A

E3 reaction correct answers uses tightly bound FAD to oxidize the lipoic acid back to
disulfide form, then transfers protons and electrons from FADH2 to NAD+ to form NADH
and H+ that are released from complex

,transcriptional regulation of pdc correct answers amount of enzyme reduced during a
fast and is increased by insulin when fed

allosteric regulation of pdc correct answers regulated by energy state of cell and by
substrates and products:

Inhibitory: nadh, acetyl-coA
activators: nad+, CoASH

pdc regulation by covalent modification (phosphorylation) correct answers -pyruvate
dehydrogenase kinase (complex associated, allosterically regulated)
-pyruvate dehydrongenase phosphatase (complex associated, regulated by calcium)
-principle form of regulation
-phosphorylated=inactive!

pdc kinase correct answers inhibited by adp & pyruvate
-pdc on (ATP/ADP)
activated by NADH and acetyl coA (PDC off)

pdc kinase occurs as correct answers tissue specific forms

where does phosphorylation of pdc occur? correct answers on pyruvate decarboxylase
subunit (E1)

where are 7/8 TCA enzymes located correct answers mitochondrial matrix

where is succinate dehydrogenase located correct answers inner mitochondrial
membrane

what does tca pathway accomplish correct answers complete oxidation of acetyl
groups to CO2

tca cycle yields energy as correct answers NADH, FADH2, GTP

TCA cycle is major source of correct answers reduced coenzymes for electron
transport and oxidative atp formation

what pathways besides tca cycle contribute reduced coenzymes for electron transport
and oxidative atp formation correct answers fatty acid oxidation
glycolysis

what are the energy yielding steps of tca cycle correct answers isocitrate dh
a-ketoglutarate dh
succinate thiokinase
succinate dh
malate dh

,what does isocitrate dh yield correct answers nadh + h+

what does a-ketoglutarate yield correct answers nadh + h+

what does succinate thiokinase yield correct answers gtp

what does succinate dh yield correct answers fadh2

what does malate dh yield correct answers nadh + h+

what is the energy yield in et/atp synthase correct answers 10 atp

E1 of a-ketoglutarate dh correct answers results in decarboxylation of a-ketoglutarate,
with transfer of other four carbons to tpp

what enzyme is complex II correct answers succinate dehydrogenase

in inner mitochondrial membrane, feeds electrons into electron transport pathway for atp
production

what reflects the energy status of a cell or energy charge correct answers ratio of
atp/adp and nadh/nad+

what kind of regulator is NADH correct answers major negative regulator

what kind of regulator is adp correct answers positive allosteric regulator

how is citrate synthase primarily regulated correct answers by availability of
oxaloacetate

how are the three enzymes that produce NADH regulated correct answers inhibited by
nadh

what is the rate limiting step of tca cycle correct answers isocitrate dehydrogenase
(allosteric enzyme)

how is a-ketoglutarate dh regulated correct answers inhibited by nadh (but not a
allosteric enzyme)

calcium activates what two tca enzymes in muscle correct answers isocitrate dh and a-
ketoglutarate dh

tca rate is dictated by correct answers rate of nadh use by electron transport, which is
regulated by need for atp

, anaplerotic reactions correct answers replaces lost intermediates to maintain pathway
when intermediates are removed, or speed it up for more energy production

what is the primary anaplerotic pathway for tca cycle correct answers pyruvate
carboxylase
(in tissues other than liver, propionyl-coA pathway is second most important)

what is a major source of added tca intermediaes in liver correct answers a-
ketoglutarate produced by transamination or by oxidative deamination of glutamate

hyperpyruvic acidemia correct answers -most often from defective E1 within pdc
complex (x linked pdhad gene)
-lots of hetero females have symptoms
-mutations can be in 1/5 other subunits or regulatory proteins
-low percent will respond favorably to large doses of B1

metaolic presenation of hyperpyruvic acidemia correct answers severe lactic acidosis in
newborn period that is fatal

neurologic presentation of hyperpyruvic acidemia correct answers hypotonic, lethargic,
mental retardation, seizures, minimal metabolic issues but cns structural abnormalities

thiamine deficiency correct answers impaired pdc leads to increased conversion
(reduction) of pyruvate to lactate
-lactic acidosis
-hypoglycemia from impaired gluconeogenesis

how does hepatic EtOH metabolism heighten lactic acidosis correct answers high nadh
drives ldh in lactate direction

isocitrate dh 1 correct answers cytosolic
-important roles in lipid metabolism and insulin release

isocitrate dh 2 correct answers mitochondria
-major role in controlling mitochondrial redox balance and mitigating cellular oxidative
damage

idh1 and 2 mutations correct answers -frequently mutated in gliomas and myeloid
leukemia
-r132 in idh1 or idh2 (r172)
-mutation of active site arginine blocks final oxidation, changing final product from a-
ketoglutarate to 2-hydroxyglutarate which accumulates to high levels

2-hydroxyglutarate correct answers strong inhibitor of a-ketoglutarate dependent
dioxygenases
-high levels results in epigenetic changes

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller HopeJewels. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $18.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

69052 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 15 years now

Start selling
$18.49
  • (0)
Add to cart
Added