Bio151

Carbohydrates

Carbohydrates are sugars with the general chemical formula $C<em>xH</em>{2x}O_x$.

• Monosaccharide: $1$ simple sugar unit

  • Examples: Glucose, Fructose

  • Memory trick: mono = one

• Disaccharide: $2$ sugars joined together

  • Memory trick: di = two

• Polysaccharide: Many sugars joined together (usually hundreds to thousands of sugar units)

  • Memory trick: poly = many

Aldose vs. Ketose

Determined by the position of the carbonyl group ($C=O$):

• Aldose: Carbonyl group is at the end of the carbon chain ($\text{ALDO} = \text{edge}$).

• Ketose: Carbonyl group is in the middle of the carbon chain ($\text{KETO} = \text{middle}$).

Glucose

• Chemical formula: $C<em>6H</em>{12}O_6$

• Classification: Monosaccharide

• Role: Major starting material for cellular respiration.

Polysaccharide Functions

• Starch: Plant energy storage

• Glycogen: Animal energy storage

• Cellulose: Building material in plant cell walls (cellulose chains are held together by hydrogen bonds)

Energetics and Cellular Respiration

Photosynthesis

Plants convert light energy into glucose:

$CO<em>2 + H</em>2O + \text{light energy} <br>ightarrow C<em>6H</em>{12}O<em>6 + O</em>2$

Cellular Respiration

Breaks down glucose to produce usable cellular energy ($\text{ATP}$):

$C<em>6H</em>{12}O<em>6 + O</em>2 <br>ightarrow CO<em>2 + H</em>2O + \text{energy (ATP)}$

Key focus areas include carbon tracking, $\text{ATP}$, $\text{NADH}$, $\text{FADH}_2$, starting materials, and key enzymes.

Phosphorylation

• Definition: Addition of a phosphate group to a molecule ($\text{Phosphorylation} = \text{add phosphate}$).