Biochemistry Exam 2 (Carbohydrates)-Questions and Answers Graded A+

Biochemistry Exam 2 (Carbohydrates)-Questions and Answers Graded A+ The 2 f-groups in a sugar - ANSWER-Hydroxyl and carbonyl The 2 carbonyl groups in sugars - ANSWER-Aldehyde and Ketone Minimum number of carbons in an aldose - ANSWER-3 Minimum number of carbons in a ketose - ANSWER-4 What's the basis for defining a sugar? - ANSWER-How it behaves in acid Aldose vs. Ketose - ANSWER-Aldose - aldehyde; ketose - ketone Triose - ANSWER-sugar with 3 carbons Tetrose - ANSWER-sugar with 4 carbons Ultimate C - ANSWER-The last C in a sugar Penultimate C - ANSWER-next to last C and last chiral center In Fisher Projection formulas, what designates a D or L sugar? - ANSWER-It is a D if the OH is to the right; it is an L if the OH is to the left Characteristics of Glucose - ANSWER-ALDOSE - most often in D form Characteristics of Fructose - ANSWER-KETOSE - most often in D form - has same sequence as glucose Epimer - ANSWER-Only 1 chiral carbon differs, rather than all Write out the formation of a hemiacetal. - ANSWER-DO IT. Write out the formation of a hemiketal. - ANSWER-DO IT. The result of ring formation - ANSWER-C1/2 (aldose/ketose) becomes chiral, anomeric In Haworth formulas, what designates an alpha and beta sugar? - ANSWER-Alpha: OH is down, same as acetal end; Beta: OH is up, opposite of acetal end In Haworth formulas, what designates a D or L sugar? - ANSWER-D: if the CH2OH is up; L: if the CH2OH is down Anomers - ANSWER-2 compounds with one or more chiral center that differ at the anomeric C Anomerization - ANSWER-The reaction that results in anomers from straight chain sugars