all C are chiral except the C in position 1 (is this for aldehydes lol

minimum 3 to make a glyceraldehyde ???? what does that mean bruh

dihydroxyacetone has no chiral centers??

• possible to have very large carbohydrates

**carbs are main source of energy for body; main ways to store energy

• lipids also store energy

mono - 1 unit that does not repeat

disaccharide - 2 units connected

poly - long chain w repeats of the same units

• idk he said something about glucose connects in diffeent way???

**hexose most important to us ; biggest group

**pentose also→ ex. ribose contained in DNA and RNA

stereoisomers !!

^^ mirror images of each other

ex.

fischer projection

• vertical parts are going into the paper

• horizontal parts are pointing towards you

D- glyceraldehyde: O group is on the right

L - glyceraldehyde: O group on the left

more than one chiral C and then what lol??

Common Carbohydrates in Biochemistry

• Ribose is the standard five-carbon sugar.

• Glucose is the standard six-carbon sugar.

• Galactose is an epimer of glucose.

• Mannose is an epimer of glucose.

• Fructose is the ketose form of glucose.

• Lactose (milk sugar) is the disaccharide found in milk.

**memorize structure of glucose (linear structure)

alcohol (OH) of C5 attacks the C (1) of C=O (aldehyde or ketone)

anomeric carbon = C1 → depends on if the attack is front or back

• OH in axial or equatorial position

• axial = alpha (front attack) ; equatorial = beta (back attack)

can interconvert? between alpha and beta cia mutarotation

alpha: OH of anomeric carbon (1) is trans to the OH of C6

beta: same side as CH2OH molecule → cis

2 possible chair conformations (bc of alpha and beta?)

• interconversion between the two but need some energy to move from one to another

• they are in equilibrium but usually 1 is prefered

derivation of glucose

If a substance oxidizes, it combines with oxygen and loses hydrogen to form another substance, (loses electrons) (OIL RIG)

• glucose phosphorylated at position 6 → glucose 6-phosphate

reducing agents lose electrons (are oxidized) to reduce another molecule

sugars can be oxidized: carbonyl → carboxyl

cyclic form opens up → carbonyl → carboxyl (oxidized to respective acid)

fehling’s reaction

• cu2+ is an agent that can be reduced by sugar (reducing agent)

• copper precipitate: visual way to test sugar

• test urine for diabetes (test for glucose)

di-saccharides

• bind together 2 monosaccharides w covalent bond

• molecule of water is removed

• sucrose forms alpha bond between position 1 and position 2 ???

The second sugar, which retains a hemiacetal structure (meaning it has a free anomeric carbon), is more reactive. Hemiacetals can easily interconvert between their cyclic and open-chain forms, allowing them to participate in further reactions, such as oxidation or reduction.

In contrast, once the anomeric carbon is involved in a glycosidic bond, it becomes part of a more stable acetal structure and is less reactive.

^ what does the picture mean?? like any of these bonds can form?

Naming Disaccharides

Identify the Anomeric Carbon:

• In maltose, the glycosidic bond is formed between the anomeric carbon of the first glucose (α-D-glucopyranose) and the hydroxyl group on the fourth carbon of the second glucose. Since the first glucose is in the α configuration, the bond is designated as α.

Nonreducing Residue:

• The first glucose unit, which is involved in the glycosidic bond and is nonreducing, is named as α-D-glucopyranosyl.

Indicate the Carbons in Bond:

• In parenthesis, indicate the carbons involved in the bond: (1→4).

Name the Second Residue:

• The second glucose unit, which is a standard D-glucopyranose, is simply referred to as D-glucopyranose.

Complete Name

• Putting this all together for maltose, we get:

• α-D-glucopyranosyl-(1→4)-D-glucopyranose

**furano or pyrano for carbon ring

other disaccharide examples

• highly branched

• synthesized and degraded for energy as demanded

• i: is the van't Hoff factor C: is the molar concentration of the solute

BETA

CELLULOSE IS A Structural Polysaccharides

1. CELLULOSE is the most abundant organic compound on earth

2. Cellulose can’t be digested by most animals so it passes through our digestive tract undigested. What’s it called?

3. FIBER

4. We lack the correct enzyme in our intestines…

5. Therefore, cellulose is NOT considered a nutrient.