Subject: What makes the glycosidic links rigid in cellulose as opposed to starch?

Hello, I'm a second year Biochemistry major at the University of Guelph. I 
was taught that alpha-1,4 glycosidic linkages of glucose in starch, 
glycogen is what makes these structures highly branched and more easily 
degraded somehow than beta-1,4 linkages that you would find in say 
cellulose. I have seen Haworth type diagrams of these structures but it 
hasn't help convince me as to why they are so physicaly different? 

Re: What makes the glycosidic links rigid in cellulose as opposed to starch?