> For the complete documentation index, see [llms.txt](https://thisispiggy.gitbook.io/my-wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://thisispiggy.gitbook.io/my-wiki/01-step-1/biochemistry/07-glycogen.md).

# 07 Glycogen

![](https://f001.backblazeb2.com/file/wikiFiles/335421C5-ADC0-40B1-AD3E-53EE46E7BB46.jpg)

* muscles cannot release glucose from glycogen

![](https://f001.backblazeb2.com/file/wikiFiles/21F7904F-6760-4B46-AE06-75D981EF0FB6.jpg)

* 1-4 linear linkage
* 1-6 branching
* branching makes it more soluble and better storage

![](https://f001.backblazeb2.com/file/wikiFiles/349B5EE0-C4CF-4A60-8D7E-DFF3210129F8.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/78B627E6-F5AC-4176-81A4-5B3D3C27F06D.jpg)

* UDP: uridine

![](https://f001.backblazeb2.com/file/wikiFiles/87D1C4BE-1FBD-426C-8727-D6D8235F839B.jpg)

* lysosomes can collect glycogen and break it down to glucose

![](https://f001.backblazeb2.com/file/wikiFiles/6B48805D-84F7-45D3-BE96-59A72A86C0D3.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/7767CA9A-AA7A-4BF4-AB68-B7D426D3FD73.jpg)

* glycogen phosphorylase shrink purple link down to 3 or so
* debranching enzyme moves purple to red, releasing one molecule of glucose (green)

![](https://f001.backblazeb2.com/file/wikiFiles/955E285E-3A4A-405A-81BA-7CB4D25771ED.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/879765D4-751C-4F4E-ADED-2FB3F3F0FED7.jpg)

* glucagon/E phosphorylates both enzymes both have opposite effects
* glycogen phosphorylase activity increases
* glycogen synthase activity decreases

![](https://f001.backblazeb2.com/file/wikiFiles/EB47750B-21DF-4949-8DC5-B06B8E73B16A.jpg)

* insulin results in dephosphorylation of both and opposite effects

![](https://f001.backblazeb2.com/file/wikiFiles/2C1D9007-E086-42F3-A22D-FC92BD97E945.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/04A791BA-4A49-4B47-A368-E3DB2316EC87.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/1C364FD6-F6ED-4FF0-BD5D-D5D8869199A8.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/E90AE91B-191B-4E81-B2CE-1F02F8C2B762.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/2D408538-A47A-44EC-8F7C-369CEDA285A3.jpg)

* activate glycogen phosphorylase in absence of hormones
* immediate activation instead of hormonal

![](https://f001.backblazeb2.com/file/wikiFiles/5C64854D-2B6C-4AA6-838C-7BD02645ACB4.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/98A874D5-FA51-4F6F-8CED-F33C24F29970.jpg)

## Glycogen Storage Diseases

![](https://f001.backblazeb2.com/file/wikiFiles/A3DD0BA9-366C-4431-A1F3-76523DC31D2E.jpg)

* liver defective enzyme: hypoglycemia
* enzyme defective in muscle: weakness

### Von Gierke

![](https://f001.backblazeb2.com/file/wikiFiles/0EA68298-ED04-4831-806B-75261E490B0F.jpg)

* can't release glucose between meals
* can't get glucose out of liver = hepatomegaly 

![](https://f001.backblazeb2.com/file/wikiFiles/D4824D28-5B6C-408B-8005-43DC466D632A.jpg)

* muscles will be ok
* no symptoms of muscle weakness

![](https://f001.backblazeb2.com/file/wikiFiles/07177D7D-9791-4E3C-9122-A44CA9E348D1.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/677B3BAA-1457-4A0E-94B0-91DD9C736FDD.jpg)

* consume corn starch between meals

### Pompe

![](https://f001.backblazeb2.com/file/wikiFiles/9805E919-3583-41D1-82F9-A731DE0A53AB.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/E2E862FA-D74A-40E0-9396-00CB03D41250.jpg)

* liver is ok, continue make glucose
* no hypoglycemia symptoms

![](https://f001.backblazeb2.com/file/wikiFiles/98949B83-AFD0-4BC4-9F5B-E082BD02EF13.jpg)

* entrapment of glycogen inside muscle cells
* enlarged tongue classic finding

### Cori

![](https://f001.backblazeb2.com/file/wikiFiles/3C8384E4-276C-4048-A6DD-4CC11E07F0FE.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/24353400-09E3-46BC-A441-B9CF5C45A411.jpg)

* gluconeogenesis intact from other sources: hypoglycemia not as severe
* no glucose in muscles either: **weakness**

![](https://f001.backblazeb2.com/file/wikiFiles/5F95A878-1E57-46B5-BCEE-D984D8E1DBFF.jpg)

* usually no seizures
* **muscle** symptoms distinguish from Von Gierke

### McArdle

![](https://f001.backblazeb2.com/file/wikiFiles/99C3F9B3-6519-46B8-B5F9-3786C23C0968.jpg)

* no liver problems, no hypoglycemis
* muscle difficulties
* can get muscle damage with exercise