Digestion and Absorption Flashcards

Flashcards covering key concepts from lecture notes on digestion and absorption, focusing on carbohydrates, proteins, lipids, absorption mechanisms, and adaptations for absorption.

Where does the digestion of carbohydrates primarily take place?

Mouth and small intestine

What enzyme, produced by the salivary glands, hydrolyzes glycosidic bonds in starch?

Amylase

What disaccharide is produced when amylase hydrolyzes starch?

Maltose

What enzyme, found in the ileum, hydrolyzes maltose into glucose?

Maltase

Sucrase hydrolyzes sucrose into what two monosaccharides?

Glucose and fructose

Lactase hydrolyzes lactose into what two monosaccharides?

Glucose and galactose

Where does the digestion of lipids primarily take place?

Small intestine

With what substance do lipids mix to undergo emulsification?

Bile salts

What enzyme hydrolyzes lipid micelles?

Lipase

Lipase breaks down lipids into which components?

Glycerol, fatty acids, and monoglycerides

Where does the digestion of proteins begin and primarily occur?

Stomach and small intestine

What type of protease hydrolyzes central peptide bonds to produce polypeptides?

Endopeptidases

What type of protease hydrolyzes peptide bonds at the end of polypeptide chains?

Exopeptidases

What enzymes hydrolyze dipeptides into amino acids?

Dipeptidases

In which part of the small intestine do nutrients enter the blood?

Ileum

How do amino acids initially move into epithelial cells when the concentration is high in the lumen?

Facilitated diffusion

What process allows amino acids to move into epithelial cells against the concentration gradient?

Co-transport

What is an example of active transport and is a special type of transport protein?

Sodium-potassium pump

How does glycerol enter epithelial cells from the ileum?

Simple diffusion

What structures transport monoglycerides and fatty acids to epithelial cells?

Micelles

Where are monoglycerides and fatty acids converted back into triglycerides inside epithelial cells?

Endoplasmic reticulum

What structures are formed when triglycerides combine with cholesterol and proteins?

Chylomicrons

How do chylomicrons exit the epithelial cells?

Exocytosis

What are the lymphatic capillaries that chylomicrons enter?

Lacteals

What is the function of microvilli in absorption?

Large surface area for absorption

What organelle provides ATP for the sodium-potassium pump in epithelial cells?

Mitochondria