carbohydrates

Question 1

What is the function of starch?

Answer 1

found in starch grains inside plant cells for an insoluble store of glucose (wont effect water potential)

Question 2

How is the structure of starch good for its function?

Answer 2

• amylose is a long chain of alpha glucose molecules joined together by 1, 4 glycosidic bonds which is coiled into a spiral held together by hydrogen bonds so it is more compact and therefore good for storage (smaller spaces)
• amylopectin is a polymer of alpha glucose that is branched due to frequent 1, 6 glycosidic bonds (also has 1, 4) so glucose can be released quickly (terminal glucose can be hydrolised when needed)

Question 3

What is the test for starch?

Answer 3

1.) add iodine
2.) positive observation = solution turns from orange to blue/black

Question 4

What is the function of glycogen?

Answer 4

store of glucose in animals in the liver and muscles

Question 5

How does the structure of glucose relate to its function?

Answer 5

• very frequent 1, 6 glycosidic bonds make it very branched so stored glucose can be released very quickly for a energy release in animals (also has 1, 4)
• very compact molecule = good for storage

Question 6

What is the function of cellulose?

Answer 6

keep the cell wall rigid and prevent it from bursting

Question 7

How is the structure of cellulose good for its function?

Answer 7

polymer of beta glucose linked by 1, 4 glycosidic bonds only
- form straight chains linked together by hydrogen bonds to form microfibrils
- every other beta glucose is upside down so the CH2OH stick out alternatively
- so it gives structural support for cells