Nutrition - Carbohydrates

saccharides

Carbohydrates are often called

sakcharon

(Greek word ___ = sugar), though not all are sweet.

watered carbon

The term “carbohydrate” means

(CH₂O)ₙ

They are the most abundant biomolecules on Earth, with many having the formula

1. Primary energy storage: starch & glycogen

2. Support long-term energy storage (alongside lipids)

3. Quick energy source (e.g., blood glucose)

4. Aid plant-based protein production in herbivores 

5. Used in making certain antibiotics

6. Cellulose in plants → textiles, paper, wood

7. Abundant in ecosystems & vital for DNA/RNA structure

8. Form structural polymers like cellulose & chitin

FUNCTIONS of Carbohydrates

materials, medicine, nutrition, and energy.

To put it briefly, carbohydrates are necessary for?

MONOSACCHARIDES
DISACCHARIDES
OLIGOSACCHARIDES 
POLYSACCHARIDES

CLASSIFICATION OF CARBOHYDRATES

BASED BY DEGREE OF POLYMERIZATION

MONOSACCHARIDES

• Simplest carbohydrates; basic units of complex carbs 

• Building blocks for polymers 

D-glucose

• is the most common monosaccharide. 

Glucose
Fructose
Galactose

• – primary energy source 

• – fruit sugar 

• – milk sugar component

Trioses:

Pentoses:

Hexoses:

Examples by number of carbon atoms: 

• glyceraldehyde 

• ribose, xylose 

• glucose, fructose

DISACCHARIDES

• Two monosaccharides linked by glycosidic bond 

• Hydrolyzable into two monosaccharides

GLYCOSIDIC BONDS 

• It is the name given to the covalent bond between the two saccharide molecules. 

• Form between hydroxyl groups of the two saccharide molecules.

Sucrose  

Lactose

Maltose

• Glucose + Fructose 

• Glucose + Galactose 

• Glucose + Glucose

OLIGOSACCHARIDES

• Found in legumes, onions, human milk 

• Often non-digestible, act as prebiotics

Raffinose, Stachyose

Examples of Oligosaccharides

POLYSACCHARIDES

• Linear or branched; generally insoluble, not sweet 

• Polysaccharides function in storage or structure. 

• Made of glucose units linked by glycosidic bonds. 

Starch

Glycogen 

Cellulose (same glucose units, different structures).

Examples of Polysaccharides

Starch (plants): amylose, amylopectin 

Glycogen (animals): highly branched, stored in liver/muscles

STORAGE POLYSACCHARIDES examples

Cellulose - plants, indigestible to humans 

Chitin - fungal cell walls, arthropod exoskeletons

STRUCTURAL POLYSACCHARIDES examples

MONOSACCHARIDES

All reducing sugars

DISACCHARIDES

Some reducing (depends on free anomeric carbon)

POLYSACCHARIDES

Non-reducing

Not Sweet & Mostly Insoluble

CLASSIFICATION BY TASTE & SOLUBILITY of Polysaccharides

Sweet & Soluble

CLASSIFICATION BY TASTE & SOLUBILITY of Monosaccharides

Sweet & Soluble

CLASSIFICATION BY TASTE & SOLUBILITY of Disaccharides

Slightly Sweet & Variable

CLASSIFICATION BY TASTE & SOLUBILITY of Oligosaccharides

1

Monomer units of monosaccharides

2

Monomer units of disaccharides

3-10

Monomer units of oligosaccharides

> 10

Monomer units of polysaccharides

MONOSACCHARIDES

Small
Sweet
Water soluble

DISACCHARIDES

Sweet
Hydrolyzable to monosaccharides

OLIGOSACCHARIDES

Found in plants
May have prebiotic roles

POLYSACCHARIDES

Storage / Structural
Often insoluble

rice, pandesal, noodles, pasta, fruits (banana, mango), milk products, root crops (potato, camote), beans, cereals, sweets

CARBOHYDRATE SOURCES IN FILIPINO DIET

Low carb
High carb

DIET TYPES 

LOW CARB

non-starchy vegetables, meat, fish, healthy fats

HIGH CARB

whole grains, fruits, starchy vegetables

SIMPLE CARBOHYDRATES (SUGARS)

COMPLEX CARBOHYDRATES

FIBER SOURCES

CLASSIFICATION OF CARBOHYDRATE SOURCES 

SIMPLE CARBOHYDRATES (SUGARS)

• Monosaccharides & disaccharides in fruits, vegetables, milk, processed foods 

fruits, fruit juices, vegetables, milk products, foods with added sugar

SIMPLE CARBOHYDRATES (SUGARS) examples

cereal grains, legumes, tubers, potatoes, sugarcane

COMPLEX CARBOHYDRATES sources

COMPLEX CARBOHYDRATES

• Starches & non-starch polysaccharides 

FIBER SOURCES

• From bread, fruits, vegetables (esp. unrefined plant foods) 

• Mostly non-starch polysaccharides from plant cell walls 

glycolysis, Krebs cycle, gluconeogenesis

METABOLISM

• Breakdown & use of carbohydrates for energy, storage, and cellular functions 

• Involves ____ regulate glucose & energy balance 

Simple sugars

Complex sugars (polysaccharides)

CARBOHYDRATE TYPES

glucose, fructose

Simple sugars examples

starch, glycogen (energy storage), cellulose, chitin (structural components) 

Complex sugars (polysaccharides) examples

1. Starts in mouth

2. Small intestine

3. Glucose

4. Cellular Respiration

CARBOHYDRATE DIGESTION process

salivary amylase

• breaks starch into smaller sugars

bloodstream

Small intestine

• sugars (monosaccharides ) absorbed into ___

Glucose

• a monosaccharide and the basic unit of carbohydrates

• transported to tissues for cellular respiration

Cellular Respiration

• a process that breaks down glucose → ATP production 

Glucose

is the main energy source. Can be used immediately, stored as glycogen, or converted to fat if in excess. 

Fates of Glucose in the Body

Gluconeogenesis

Low glucose → body converts protein into glucose

Lipogenesis

Excess glucose turns into fat for long-term storage

• Providing a Food Source for Oral Bacteria 

• Acid Production

• Enamel Demineralization

• Long-term Acid Exposure

ROLES OF CARBOHYDRATES IN DENTAL CARIES

Streptococcus mutans, Lactobacillus

Acid Production

• Bacteria (___ , ___) ferment sugars → lactic acid 

5.5

pH drops below ___ → enamel starts dissolving

calcium & phosphate

Enamel Demineralization

• Loss of ___ & ___ → weakens teeth → early cavities

20–30 mins

remineralization 

Long-term Acid Exposure

• Acid lasts 1. ___ mins after eating

• Frequent snacking → less time for 2. ___

1. Frequent/high sugar intake 

2. Sticky foods stay longer on teeth 

3. Poor oral hygiene, diet and nutrient intake (especially calcium and fluoride)

Factors that Speed Decay

1. Saliva flow & composition → saliva washes away food, neutralizes acids, and provides minerals.

2. Oral hygiene habits → brushing & flossing remove plaque and food particles.

3. Diet & nutrient intake → especially calcium & fluoride, which help remineralize enamel.

PREVENTION

OBESITY
NIDDM (Type 2 Diabetes)
CARDIOVASCULAR DISEASE
CANCER
GI DISEASES (NON-CANCER)
DENTAL CARIES

6 CARBOHYDRATE RELATED DISEASES

OBESITY

• Rising worldwide; ↑ risk for diabetes & heart disease. 

• High-carb foods give short-term fullness; less efficient fat storage than dietary fat. 

• Cause: Excess calories + low activity, not carbs alone.

NIDDM (Type 2 Diabetes)

• Linked to obesity, genetics, rapid lifestyle change. 

• Protective: High fiber & low-GI carbs (legumes, fruits, whole grains).

• Sucrose OK if calorie-controlled & nutrient rich diet maintained

CARDIOVASCULAR DISEASE

• Risks: Central obesity, high saturated fat. 

• Whole grains, fruits, veggies replace harmful fats & provide antioxidants. 

• Fiber (beta-glucans) lowers cholesterol. 

CANCER

• Colorectal: Fiber fermentation (butyric acid) protective. 

• Fiber dilutes carcinogens & improves gut pH. 

• Phytoestrogens in carbs may protect against breast cancer. 

• Obesity ↑ cancer risk more than carbs themselves. 

GI DISEASES (NON-CANCER)

• Fiber & resistant starch → heavier stools, less constipation. 

• Bran/cereals reduce diverticular disease risk. 

• Carbs support healthy gut bacteria

DENTAL CARIES

• Sugars & high-GI starch → acids → decay risk. 

• Risk ↑ with frequent snacking, poor hygiene, low fluoride. 

• Prevention: Oral hygiene & fluoride use.

galactosemia, glycogen storage diseases

Rare inherited disorders

sucralose

Ex. splenda

sugar na ginagamit sa drinks

Xylitol

natural sugars

non cariogenic

softdrinks

least cariogenic

gums and candies

most cariogenic

streptococcus mutans

bacteria and microorganism

in enamel

lactobasilus acidophilus

bacteria and microorganism

in dentin

actinomycosis viscosus

bacteria and microorganism

in cementum

type 1 diabetes

"1 missing"

No insulin produced

type 2 diabetes

"2 problems"

insulin resistance

reduces insulin