Give me two questions answere please Transcribed Image Text: QUESTION 7 Give the systematic name of the disaccharide shown below by filling in the blanks for each part of the name. (For instance, lactose is galactose b (1→4) glucose) он он но но OH он он но first sugar name Greek letter (a, b, ab, aa, ba, bb) first number – – second number second sugar name QUESTION 8 Which type of stereo isomer are these two molecules? alpha-D-glucose and alpha-D-galactose
QUESTION 7
The systematic name of the disaccharide shown below can be determined by filling in the blanks for each part of the name.
To determine the systematic name:
1. Identify the first sugar name.
2. Determine the Greek letter (a, b, ab, aa, ba, bb) that represents the glycosidic bond.
3. Specify the first number.
4. Indicate the second number.
5. Identify the second sugar name.
Now, let’s use this approach to determine the systematic name of the disaccharide shown:
OH
/
OH H O HO
3 │ │ │ │
HO–C–C—C—C–OH
│ │ │ │
OH HO HO
To fill in the blanks:
1. The first sugar name: This can be determined by considering the sugar molecule on the left side of the glycosidic bond. In the diagram, the left sugar is glucose.
2. Greek letter: The Greek letter represents the configuration of the anomeric carbon involved in the glycosidic bond. In this case, since the OH group is pointing downwards (cis orientation), the Greek letter would be b.
3. First number: The first number represents the carbon atom where the glycosidic bond is formed in the first sugar (glucose). In this case, the glycosidic bond is formed at the carbon 1 (C1) of glucose.
4. Second number: The second number represents the carbon atom where the glycosidic bond is formed in the second sugar molecule. In the diagram, the glycosidic bond is formed at the carbon 4 (C4) of the second sugar molecule.
5. Second sugar name: The second sugar molecule is located on the right side of the glycosidic bond. In the diagram, the right sugar molecule is glucose.
Applying this information to the given disaccharide structure, the systematic name would be “glucose b (1→4) glucose” since both sugar molecules are glucose and the glycosidic bond is formed between C1 of the first glucose molecule and C4 of the second glucose molecule.
QUESTION 8
The two molecules mentioned, alpha-D-glucose and alpha-D-galactose, are both types of sugar molecules and can be classified based on their stereochemistry. Stereoisomers are molecules that have the same molecular formula and connectivity of atoms but differ in their spatial arrangement.
In this case, both molecules have the prefix “alpha” indicating that the hydroxyl group attached to the anomeric carbon is in the axial position. The “D” prefix indicates the configuration of the molecule based on the D-glyceraldehyde molecule.
To determine the type of stereoisomer:
1. Identify the stereochemical prefix (D or L) and the configuration (alpha or beta) for each molecule.
2. Compare the stereochemical prefixes and configurations of the two molecules.
In this case, both molecules have the same stereochemical prefix (“alpha-D”) and configuration (“alpha”). From this information, we can conclude that alpha-D-glucose and alpha-D-galactose are a pair of stereoisomers known as anomers. Anomers are stereoisomers that differ in the configuration of the hydroxyl group attached to the anomeric carbon (C1 in this case), while maintaining the same configuration at all other chiral centers.