Overview of carbohydrates as essential macromolecules in biology.
Serving Size: 216 g
Calories: 590 (Calories from Fat: 306)
Total Fat: 34g (52%)
Saturated Fat: 11g (55%)
Cholesterol: 85mg (28%)
Sodium: 1070mg (45%)
Total Carbohydrate: 47g (16%)
Dietary Fiber: 3g (12%)
Sugars: 8g
Protein: 24g
Vitamin A: 6%
Vitamin C: 6%
Calcium: 30%
Iron: 25%
Percent Daily Values are based on a 2,000 calorie diet.
Carbohydrates serve as a primary energy source for organisms.
Producers: Plants and autotrophs synthesize carbohydrates.
Consumers: Animals and heterotrophs utilize carbohydrates and release carbon dioxide.
Monosaccharide: Basic building block of carbohydrates.
Glucose is a key monosaccharide that can form pyruvate for ATP production in mitochondria.
Carbohydrates can exist as:
Monosaccharides (1 unit)
Disaccharides (2 units)
Polysaccharides (multiple units)
Types of polysaccharides include:
Alpha carbohydrates (starch, glycogen)
Beta carbohydrates (cellulose, chitin, peptidoglycan)
Photosynthesis: Plants convert CO2 and H2O into carbohydrates.
Energy conversion processes include:
Photosynthesis: CO2 + H2O + sunlight → O2 + (CH2O)
Energy Storage in forms of glucose, starch, glycogen, and fats.
Cellular Respiration: Glucose + O2 + ADP + Pi → CO2 + H2O + ATP
Carbohydrates comprise carbon, hydrogen, and hydroxyl groups.
Key structural features:
Carbonyl (C=O) group
Hydroxyl (-OH) groups
High-energy C–H bonds
General formula: (CH2O)n
Example: Glucose (C6H12O6)
Monosaccharides vary based on the number of carbons in their structure.
They can spontaneously form ring structures in solution.
Glucose (monosaccharide) exists in three forms:
Linear form (rare)
α-glucose ring
β-glucose ring
The orientation of hydroxyl groups differentiates α and β forms.
Stability: β-glucose is more common due to stability.
During cellular respiration, glucose is oxidized to convert stored energy into usable forms (ATP).
Mitochondria are the organelles responsible for ATP production from glucose.
Monosaccharides link through covalent bonds known as glycosidic linkages.
Types of glycosidic linkages:
α-glycosidic linkage
β-glycosidic linkage
Example of disaccharides formed via these linkages: Maltose, Lactose.
Lactose example involves a combination of glucose and galactose through glycosidic linkages.
Polysaccharides formed by repeated units of monosaccharides:
a-1,4-glycosidic linkages
Unbranched structures (e.g., amylose)
α-glucose chains: Store chemical energy.
β-glucose chains: Form fibrous structures, including cell walls in many organisms.
Starch
Highly branched helices of α-glucose.
Stores energy for plants.
Glycogen
Energy storage in animals (liver and muscles).
β-glucose chains: Have straight chains with hydrogen bonds, making them difficult to hydrolyze.
Examples include cellulose, chitin, and peptidoglycan which provide structural support in cell walls.
Polysaccharide Chemical Structure Function | ||
Chitin | B-1,4-glycosidic linkage | Structural support in fungi |
Peptidoglycan | B-1,4-glycosidic linkage | In bacterial cell walls |
Chitin: Used for support in fungi and exoskeletons of insects/crustaceans.
Peptidoglycan: Provides structural support in bacterial cell walls.
Carbohydrates are crucial for energy storage and utilization in organisms.
Plants synthesize carbohydrates; animals consume them and produce CO2.
Core structures include monosaccharides, disaccharides, and polysaccharides differentiated by their bonding and functional properties.
Alpha and beta carbohydrates are types of sugars that differ based on how a specific chemical group (the hydroxyl group) is arranged.
Alpha Carbohydrates (α): In alpha sugars, the hydroxyl group on the first carbon is placed below the ring structure. This form is commonly found in energy-storing sugars like starch and glycogen.
Beta Carbohydrates (β): In beta sugars, the hydroxyl group on the first carbon is positioned above the ring structure. This form is found in structural sugars like cellulose, which helps support plants.
In simple terms, the main difference is that alpha forms