Carbohydrate Metabolism How is glucose used and stored in the body? - - PowerPoint PPT Presentation

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Carbohydrate Metabolism How is glucose used and stored in the body? - - PowerPoint PPT Presentation

Oct 11, 2022 381 likes •617 views

Carbohydrate Metabolism How is glucose used and stored in the body? 1. Complex carbohydrates (polysaccharides) are ingested starch from plants (wheat, rice, potatoes, and maize) is broken 2. Excess glucose is stored in liver 3. Glycogen is

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SLIDE 1

Carbohydrate Metabolism

How is glucose used and stored in the body?

  • 1. Complex carbohydrates (polysaccharides) are ingested

starch from plants (wheat, rice, potatoes, and maize) is broken

  • 2. Excess glucose is stored in liver
  • 3. Glycogen is broken down into glucose monomers to be used in glycolysis

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SLIDE 2

Carbohydrate Metabolism

Polysaccharides

Monosaccharide - Oligosaccharides – linkage of ____________________________________ disaccharide of glucose Polysaccharides - linkage of

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SLIDE 3

Carbohydrate Metabolism

Polysaccharides

Glycosidic bond - a bond between the #1 _________________________________

  • can be between __________________________________
  • bond can be in the __________ depending the OH orientation

around C#1

α- β- 3

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SLIDE 4

Carbohydrate Metabolism

Polysaccharides Polysaccharides can be linear or branched

Two forms of starch:

  • 1. amylose -
  • 2. amylopectin -

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Carbohydrate Metabolism

Glycogen Glucose from ingested complex carbohydrates ______________________ Excess glucose is used to form ________________________. During low glucose, glycogen can be broken down into glucose for glycolysis Glycogen - a branched polymer _____________

  • about _____________ units per glycogen molecule
  • linear portions have ________________________
  • branch points are __________________________
  • 13: average chain length of glycogen branches

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SLIDE 6

Carbohydrate Metabolism

Glycogen Break down of glycogen

  • glucose is released from glycogen at
  • highly branched structure allows for release of many ______________

_____________________________

  • allows for quick _____________________ at times of need

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SLIDE 7

Carbohydrate Metabolism

Glycogen breakdown Glycogen phosphorylase - enzyme that releases

  • uses Pi to phosphorylate glucose to G1P, breaks

Phosphoglucomutase - enzyme that isomerizes

  • this G6P can then be put directly into

_________________ α-1,6 branch bond broke by ______________________

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SLIDE 8

Carbohydrate Metabolism

Glycogen breakdown Glycogen phosphorylase - enzyme that releases _________________

  • note that the phosphate for G6P formation from glycogen
  • thus, glycolysis from glycogen
  • net from glycolysis

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SLIDE 9

Carbohydrate Metabolism

Glycogen formation Energy for glycogen production from glucose uses _________________ UDP-glucose pyrophosphorylase - enzyme that carries out this reaction ____________________ to form uridine diphosphate glucose (UDPG) First step:

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SLIDE 10

Carbohydrate Metabolism

Glycogen formation Second step:

  • UDPG is linked to another ________________________________
  • carried out by __________________________________

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Carbohydrate Metabolism

Glycogen formation Branching step:

  • branching enzyme transfers 7 glucoses from ______________________

_____________________________________________

  • forms _________________
  • each transferred segment

comes from at least

  • each branch point at least

4 glucoses

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SLIDE 12

Carbohydrate Metabolism

Glycogen formation Why do athletes that perform endurance events (long distance running, cycling) eat pasta before exercise? Glycogen loading (carbo loading) - _________________________ __________________________________________

  • extra glycogen allows for ______________________________

by anaerobic glycolysis during extended exercise

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SLIDE 13

Carbohydrate Metabolism

Gluconeogenesis

  • Conversion of ___________________
  • essentially ____________________, but not exactly
  • _________________ of glucose
  • occurs in ________________
  • occurs in time of _________, __________, or intense _________
  • requires energy (ATP) input

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SLIDE 14
  • Many of the steps in glycolysis are ________
  • 3 steps in glycolysis are irreversible:

These reactions must be __________ in gluconeogenesis Carbohydrate Metabolism

Gluconeogenesis

  • 1. G6P production from ______________

_____________________

  • 2. F1,6BP production from ___________
  • 3. ________________________ from

phosphoenolpyruvate (PEP)

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SLIDE 15

Carbohydrate Metabolism

Gluconeogenesis

  • carried out by enzyme __________________
  • uses 1 ATP
  • reaction takes place

Step 1. Conversion of pyruvate to __________

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Carbohydrate Metabolism

Gluconeogenesis Step 2. Conversion of oxaloacetate to

  • carried out by enzyme phosphoenolpyruvate

carboxykinase

  • uses 1 instead of ATP
  • reaction takes place in ________________

+ GTP Mg2+ Phosphoenolpyruvate carboxykinase C C CH2 O O- O P O O- O-

phosphoenolpyruvate

+CO2 + GDP

  • now PEP is produced,
  • PEP continues through gluconeogenesis

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SLIDE 17

Carbohydrate Metabolism

Gluconeogenesis

  • carried out by enzyme ________________

___________________________

  • removes __________________ from F1,6BP
  • reaction takes place in ________________

1 2 3 4 5 6 7 8 9 10 11

Step 9. Conversion of F1,6BP

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SLIDE 18

Carbohydrate Metabolism

Gluconeogenesis

  • carried out by enzyme ________________

_______________________________

  • removes phosphate from G6P
  • reaction takes place in

1 2 3 4 5 6 7 8 9 10 11

Step 11. Conversion of G6P to _____________ Gluconeogenesis and glycolysis are not exact reversals of each other,

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SLIDE 19

Carbohydrate Metabolism

Gluconeogenesis

1 2 3 4 5 6 7 8 9 10 11

Entry points for gluconeogenesis

  • 1. Lactate can be
  • 2. Amino acids can be converted to
  • 3. Glycerol can be converted to

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SLIDE 20

Carbohydrate Metabolism

The Cori Cycle

  • fast twitch muscle mostly carries out

.

  • during exercise such as sprint

fast twitch muscles will _______ ________________________

  • lactic acid is transported _____
  • lactic acid is converted to

glucose via _______________

  • glucose is shuttled back to

__________________

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Carbohydrate Metabolism

The Cori Cycle Why warm down or have massage after exercise?

  • muscle soreness after exercise
  • warm down or massage keeps

blood flowing to ____________ _______________________

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Carbohydrate Metabolism

The Cori Cycle Carl Ferdinand Cori & Gerty Theresa Cori

  • naturalized Americans
  • born in Prague
  • worked at the State Institute for the Study
  • f Malignant Diseases (now the Roswell

Park Cancer Institute) in Buffalo, New York

  • defined Cori Cycle in 1929
  • Nobel Prize in Physiology or

Medicine in 1947

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