Digestive system p2

What do digestive enzymes do?

Break macromolecules into smaller absorbable units.

What are carbohydrates broken into?

Monosaccharides (glucose, fructose, galactose).

What form of carbohydrates can be absorbed?

Only monosaccharides.

What are proteins broken into?

Amino acids, dipeptides, and tripeptides.

What lipid breakdown products are absorbed?

Monoglycerides and free fatty acids.

What are nucleic acids broken into?

Nucleotides → bases, sugars, phosphates.

Where does most absorption occur?

Small intestine.

What percentage of electrolytes and nutrients are absorbed in the small intestine?

Most nutrients and ~80% electrolytes.

How are most nutrients absorbed?

active transport

Which nutrient is NOT absorbed via active transport?

Lipids

what regulates calcium absorption?

Calcitriol (vitamin D) and PTH.

How is iron absorption controlled?

Based on body need.

How much water enters the small intestine daily?

9 L

How much water is absorbed in the small intestine?

95%

How is water absorbed

osmosis

What is a nutrient?

Substance needed for growth, repair, maintenance.

What are the 3 macronutrients?

Carbohydrates, lipids, proteins.

What are micronutrients?

Vitamins and minerals.

What are essential nutrients?

Nutrients the body cannot make sufficiently.

Main function of carbohydrates?

ATP production

What cells rely heavily on glucose?

Neurons and RBCs

What happens to excess glucose?

Stored as glycogen or fat.

Main functions of lipids?

Energy, insulation, protection.

What is cholesterol used for?

Membrane stability and hormone/bile precursor.

What do lipids help absorb?

Fat-soluble vitamins.

What are complete proteins?

Lack one or more essential amino acids.

Main function of proteins?

Structure and functional molecules (enzymes, hormones).

What happens if amino acids are missing?

Used for energy or converted to fat/carbs.

What are vitamins?

Organic compounds needed for metabolism.

Main role of vitamins?

Act as coenzymes.

Two types of vitamins?

Water-soluble and fat-soluble.

What does vitamin C do?

Collagen synthesis and antioxidant.

What disease is caused by vitamin C deficiency?

Scurvy

What does vitamin D do?

Help absorb calcium

What does vitamin K do?

Blood clotting

What are minerals?

Inorganic nutrients for body function.

What is calcium used for?

Bones, teeth, muscle and nerve function.

What is iron used for?

Hemoglobin and oxygen transport.

What mineral is needed for thyroid hormones?

Iodine

How does WHO define obesity?

Excess fat posing health risk.

What tool is commonly used to assess weight?

BMI

BMI formula (US)?

Weight (lb) / height (in²) × 703.

Limitation of BMI?

Does not account for body composition.

What is BMI used for?

Screening, not diagnosis.

What metabolic condition is linked to obesity?

Type 2 diabetes.

What cardiovascular risks are increased?

Stroke, hypertension, heart disease.

What is metabolic syndrome?

≥3 risk factors (BP, glucose, fat, HDL, triglycerides).

Other conditions linked to obesity?

Sleep apnea, osteoarthritis, depression, cancers.