Biological Molecules p50-56 Flashcards
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Name the three polysaccharides.
cellulose, glycogen, starch
What is true for monosaccharides and disaccharides but not for polysaccharides?
poly are not sugars
What are the two things starch is made of?
amylose and amylopectin
Describe the structure of amylopectin.
Many 1,4 linked alpha-glucose molecules; contains 1,6 too which are branch points
How is glycogen and amylopectin similar?
Both have 1,4 links formed by glycosidic bonds formed by condensation. 1,6 links of glucose too, forming branches. Both are polysaccharides.
Describe the structure and shape of amylose.
Alpha-glucose molecules are 1,4 linked. Chains coil up to form a helical shape, so it is compact.
How does glycogen become visible on liver and muscle cells?
Glycogen clumps up together to form granules which are visible and act as an energy reserve.
Compare the chains of amylose and amylopectin.
amylose has longer chains than amylopectin
What is a difference between glycogen and amylopectin?
Glycogen has more branches.
How is cellulose different from the other polysaccharides?
It is a polymer of beta-glucose
Why is cellulose the most abundant?
- present in cell walls
- slow breakdown
What is the purpose of cellulose?
Strong for structural purposes
Describe how the beta-glucose molecules are joined together to make cellulose.
One is 180 to the other to form 1,4 links
Discuss the strength of cellulose and the way that the glucose molecules are linked together.
Linkage between H and O are weak. Many hydrogen bonds= enormous strength
How are microfibrils formed?
60-70 cellulose molecules are tightly cross-linked by hydrogen bonding, forming bundles
